主持人 潘家华（中国社会科学院城市发展与环境研究所所长）：非常高兴，今天我们有幸请到德国发展研究院院长、德国政府全球变化咨询委员会副主席、中国环境与发展国际合作委员会委员、城市发展与环境研究所特邀专家迪尔克·梅斯纳教授来到咱们研究生院。

德国发展研究院是中国社科院选定为合作机构的四家国际知名智库之一，Dirk教授作为院长，长期致力于全球治理、全球发展、气候变化、低碳发展等领域研究，我们一直合作得非常愉快。发展低碳经济，应对气候变化，保障能源安全，推动经济结构调整，已成为国际社会共识。当前基本上所有的发达国家以及主要发展中国家都在积极发展低碳经济。下面我们用热烈的掌声请Dirk教授为同学们作主题为“全球低碳经济大转型”的报告。

迪尔克·梅斯纳（德国发展研究院院长）：在讲座之前，我想先向大家解释一下WBGU这个缩略语的含义，它意为德国全球变化咨询理事会。我是位于德国西部的德国发展研究所的所长，同时也是全球变化咨询理事会副会长。德国全球变化咨询理事会的研究课题是由德国9家主要研究机构在全球变化与可持续发展领域进行合作研究。所以我们9位研究所的所长都是德国政府的气候顾问，为德国政府提供关于能源问题以及其他全球气候变化动态的相关建议，例如，臭氧化就是我们关注的一个重要问题。今天我为各位所做的报告是“全球低碳经济大转型”。我的演讲基于《转变中的世界：可持续发展的社会契约》，这是德国学术界所做出的一份450页的报告。

我将围绕四个问题讲述。第一，低碳转型。从全球视角探讨这个转型需要怎样的速度以及称之为“大转型”的原因。为什么称其为大转型？第二，我们是否能够应对这一转型，我们如何解决问题。我会提出5个好消息和推动力，同时也会提出5个挑战和障碍。我们在推动转型时不能盲目乐观。第三，关于转型中最重要的部门，我关注的是能源、城市化和土地使用。第四，关于低碳转型中的主要推动力量：协同进化、临界点、可持续发展的社会契约。以上是我将要介绍的四个方面。

首先，我们来看第一个问题：大转型、全球转型，需要怎样的速度？第一张幻灯片是关于“我们为什么需要全球低碳转型？”（见图1）我这里要引用曾在几年前获得诺贝尔经济学奖的美国经济学家迈克尔·斯彭斯的一句话：“在全球新经济中我们实在不能扩大现在的这种增长模式。”我认为这是我们要记住的，由于自然的原因，在全球新经济中我们实在不能扩大现在的这种增长模式。为什么不可能呢？因为2050年地球人口将达到90亿，世界的GDP将从2010年的60万亿美元达到2030年或2040年的180万亿美元，全世界的中产阶级人数将大量增加，如果这些中产阶级继续现在的增长模式和消费模式，我们在全球范围内无法实现可持续发展。关于中产阶级，请大家注意幻灯片右下角的表格：这些数据是对最近的和对未来的预测。1990年的数据显示，中产阶级，根据美国统计数据的定义，是指年收入在4000美元至40000美元之间的个人（此处数据似乎有误，但演讲者原文如此）。按此标准，20年前，在1990年全球有13亿人口属于中产阶级，80%生活在OECD国家，即西方的工业化国家。只有20%生活在非西方国家。请看2009年的数字，这是最近的情况，当时有18亿中产阶级，50%仍生活在OECD国家，另外的50%生活在非OECD国家，这是一个良好的趋势，因为这意味着那些非OECD国家、发展中国家，经济的高速发展导致收入水平迅速提高。但是从可持续发展的角度看，这意味着现在由新的中产阶级驱动的新兴的增长需要保持可持续性。因为，如果仍维持像以往一样的高碳、高资源密集型经济发展模式，在地球疆界我们将无法持续生存。我们可以从表中看到，在并不遥远的2030年，全球将会有48亿中产阶级，差不多50亿人，80%生活在非OECD国家，只有20%生活在OECD国家，这与20年前的数据相比是一个剧烈的转变，同时也是全球经济的一个巨大变化。从可持续发展的角度看，这是很重要的，因为20年前，1992年召开的关于可持续发展的联合国大会认为OECD国家能够实现可持续发展，之后非OECD国家可以复制它们的做法。但是现在的情况不同了，因为经济增长发生在非OECD国家，全球的中产阶级有80%生活在非OECD国家。这意味着OECD国家和新兴经济体，如中国、印度、巴西和南非，需要同时转向可持续经济、低碳经济。你们可以看到，如果这些新兴中产阶级依赖高碳增长，我们就无法遏制全球变暖的趋势，而这也是全球低碳谈判已经达成的协议。所以我们需要全球，而不仅仅是一些主要国家，都转向低碳经济，中国也是这一领域的主要推动者。

图1 我们为什么需要全球低碳转型

第二张幻灯片关于全球转型（见图2）。左面的图形表示的是地球的疆界，物理的、化学的、生物的疆界。自然科学家能够比15年或20年前更好地向我们解释宇宙的形态，使我们了解在宇宙中如何组织全球经济。对于所有人来说重要的挑战在于如何在地球的疆界中发展出经济增长的模式，我们要接受这些自然的疆界，如果超越这些疆界，就可以看到右图中的地球系统的临界点。如果全球再变暖3～4摄氏度或更高，亚洲的季风可能会崩溃，美洲的亚马孙森林可能会崩溃，北极的冰川会融化。这意味着，如果我们的经济增长模式不能保持在地球的自然疆界之内，那么我们会在未来十年创造出一个新的地球系统。这一点在当前的社会中并不为科学界之外的很多人所理解。我与德国人探讨这个问题时，他们都理解我们需要停止全球变暖的进程，但是几乎没有人明白如果我们仍像之前那样，地球的基本系统将会发生改变。因此我们需要进行全球低碳转型。

图2 全球转型

这张幻灯片（见图3）我向大家展示的是在与全球变暖2摄氏度的目标相容的情况下我们还可以向大气排放多少温室气体。这是我们达成的协议，因为科学家们认为：“如果全球气温升高超过2摄氏度，我们会遇到严重问题。”那么，这对于全球的气候预算、温室气体排放预算意味着什么呢？我们在这一领域与潘教授合作——潘教授和他的团队提出了类似的预算法，我们提出在2摄氏度的升温空间中还有多少的温室气体排放的预算。我们提出的数字是从今天到2050年，全球还可以排放7500亿吨温室气体。如果我们有67%的可能实现这个数字，就能保持在2摄氏度的升温空间内。为什么不是100%的可能性？因为100%的可能性意味着非常小的预算，我们无法组织全球的低碳转型，也存在一定风险。750亿吨，这个数字表示多少呢？如果能够把温室气体排放稳定在当前水平，这个预算会在20年内用尽。这意味着用以组织我们的增长模式和观念转变的预算很小，因此这不是一件简单的事，而是一个大转型。我们所做的下一步是计算了温室气体排放不同的峰值年份。图中绿色曲线代表的是我们计算的以2011年为峰值年，另外的曲线分别是2015年和2020年。可以看到，如果我们当时是在2011年达到峰值（当然，事实上不是这样），为了保持在7500亿预算之内，每年温室气体排放量应减少3.7%。3.7%是可以想象的，劳动生产率和能源效率年均提升3.7%是可以实现的，我们在其他很多部门也实现过这样的效率提升。中国是这方面的领头羊，所以3.7%是可能实现的。图3显示，如果峰值是在仅仅8年后的2020年，需要每年减少9%的温室气体排放。这是很大的挑战，可能无法实现。这意味着我们的时间非常紧迫，我也感到非常紧张。你会发现，我对于可利用的技术、需要的条件很乐观，但是重要的是时间压力。接下来的几年里要达到峰值，因此关于气候的协商很重要，但是某种意义上也令人沮丧，因为我们的进展并不快。不过另一方面情况也在改善，中国是目前最重要的低碳技术投资者，德国仅次于中国，中德两国是这一进程中最重要的国家。所以，何时达到峰值是重要的，我们时间紧迫。我将这次低碳转型称为人类历史上再一次大转型，历史上与之相提并论的只有另外两次转型。一次是1万年前的新石器时代革命时期，人类发明了农业，开始建造村庄，走出狩猎采集模式的文明。那是人类历史上的巨大转变。当时地球上只有几百万人口。全球视角的第二次大转型是约250年前的工业革命，当时地球上人口数为10亿。第二次转型是基于由化石燃料驱动的能源革命，而之前的农业社会的基础是动物的能量以及在农业部门的农民，燃料是木材。第三次大转型就是这一次，我们还需要进行能源转型，因为在90亿人口的情况下，我们要走出化石驱动的能源系统，需要停止温室气体排放。这是下一个十年中我们所面对的挑战。正如之前我们已经看到的，时间紧迫。这一次的低碳经济可持续发展转型与之前人类经历的两次转型——新石器时代革命和工业革命——有一个显著差异，之前的两次转型是演进，它们自然而然地出现，不是人类组织的。而本次低碳经济可持续发展转型需要人类的管理和政治上的指导，需要人为促使发生。高碳经济不能自动摆脱，因此刺激措施很重要，决策者和研究机构都要发挥作用。

图3 在与全球变暖2℃的目标相容的情况下向大气排放的温室气体

这是关于为什么这次转型是全球的而且是大转型的最后一张幻灯片（见图4）。科学界有一个关于“人类世”时代的新争论，这是由保罗·克鲁岑推动的。可能有听众知道，他是化学专家、自然科学家，如果你不知道他的名字，你该知道他在其研究领域是第一人，他是世界首位观察到大气层的臭氧破洞在扩大的科学家，也因此获得了诺贝尔奖。保罗·克鲁岑和其他自然科学家提出一个关于可持续发展的新见解，他们提出大概是从20世纪末开始，在过去二三十年里我们正处于一个新的形势，在地球45亿年的历史上（各位知道人类的历史只有22万年），人类是地球系统中最强大的地质改变力量。这是非常有力的论点，因为直到最近，我们还认为地球系统是由自然科学的法则驱动的，生存在地球上的人类是其中的一部分，也许我们毁坏了一些森林，污染了海洋，但是我们不能影响地球动力系统。但是现在，数据显示了不同的情况，自从20世纪末以来，人类是改变地球系统地质的最大力量，这个观察很重要，因为这意味着人类对于驱动地球系统负有责任，如果延续之前的高碳、高资源消费型经济增长方式，我们会创造出一个新的地球系统。所以这就带来了一些启示：整个国际社会需要学习如何驱动地球系统，如何管理地球生态系统——海洋、森林和大气，需要为此制定制度。正如大家所知，关于地球生态系统正在进行国际合作，需要标准和价值观。管理地球系统，使其可持续发展，要以全球视角看待全人类。除此之外，还需要发明和实施能够使90亿人类可持续发展的经济增长模式；还要管理很多不同的时间标度。人类不太擅长从长期角度进行管理，也许中国人在这一方面比较擅长，而在西方的经济和政治体系中，短期主义盛行。我们需要从长期的角度思考，因为我们要考虑到长期中地球的动态系统。由于我们会改变地球的动态系统，所以需要考虑到代际动态变化和代际繁荣。我希望像中国这个具有悠久历史的国家能在这方面帮助我们学会这一点。我们可能已经处于“人类世”时代。

图4 为何本次转型是全球的大转型

当前展示的幻灯片（见图5）是我数月之前找到的，它非常有趣，因此我与大家分享。我曾与现年93岁的美国经济学家福格尔先生通过电话探讨过它，福格尔先生目前还在大学工作，他曾因为全球效应的创新研究获得诺贝尔奖，他的研究成果与我们的思想很相近：这三大转型分别是新石器时代革命、工业革命以及现在的可持续发展革命。在这里你们能看到我们已经讲过的第一次转型，福格尔先生展示的是：大概从1万年前新石器时代革命开始，在那之后的几千年里，大概每隔一千年，人类会有一项大的创新并产生巨大的影响，人类发明了城市、数学、农业革命、印刷术，如果没有印刷术，那么也不会有科学和工业革命，也不会有人类文明的发展。我们可以看到，250年前的工业革命是由创新过程加速驱动的。福格尔发现，每隔三四十年就会出现一个大的创新，创新过程提速了。这是第二次大转型。现在的第三次低碳转型就在眼前，我们需要加速创新过程使得转型发生在地球疆界之内，发生在7500亿吨温室气体排放预算之内。问题在于，我们是否有能力在全球范围内组织好那些创新？这是我接下来要谈的。我们研究了很多其他的转型：中国20世纪70年代末开始的工业革命，迎来了加速发展和结构调整；20世纪90年代拉丁美洲的结构调整；60年前欧盟的出现；等等。虽然这些不是之前我讲过的两次大转型，但是它们都是相关的重要转型，如果我们观察这些社会经济转型的驱动力量，可以了解到的有四种主要的驱动力量，我认为这四种驱动力量对于当前的低碳可持续发展大转型也有重要的相关意义。第一个驱动因素是愿景，如果你真的想改变一个系统，例如现在变为低碳可持续发展的系统，你要知道前进的目标是什么，你需要一个愿景。我们的报告中有两个有趣的转型可以证明愿景的重要性。报告中讨论了100年前愿景驱动的奴隶制的废除，描述了同样由愿景驱动的欧盟的出现，所以愿景对于大转型可能至关重要。第二个驱动因素很好理解，是技术，创新的迅速扩散。实现低碳转型，需要很多部门的低碳技术的创新，因此创新的迅速扩散很重要。30年前开始的IT革命改变了全球经济的很多方面，现在我们需要低碳可持续发展的技术创新。第三个驱动因素，在很多情况下是危机。人类经常在面临严峻考验时改变行为模式。因为改变模式和进行创新对于社会、经济、私营公司、公共公司以及个人都很困难，遵循惯例很容易，面临困境会带来模式的转变。世界是在2008年金融危机后改变了组织经济的模式。这一次，谈到气候挑战，我们需要在遭遇严重问题之前做出转型。因为科学家们已经向我们展示，如果我们的气温升高4摄氏度，其后果会极其严重，地球系统达到临界点，我们可能无法应对自然环境的变化。所以要避免这一危机。第四个驱动因素是知识，如果我们理解全球确实存在问题，这些知识会帮助我们调整政策、制度、刺激措施、增长模式。低碳转型需要的是基于愿景、技术、知识的转型模式，要避免基于危机的被迫转型。

图5 技术革命

在全球的低碳转型中我们现在处于什么位置？全球的低碳转型并非今天开始的，转型已经在中国、在欧洲、在全世界于几十年前开始。正如之前我讲到的，现在我们可以看到五个好消息和五个主要的挑战。实现转型需要保持乐观，所以我们首先叙述好消息，但是为了避免盲目乐观，我们也要意识到挑战后的存在。我们研究小组的物理学家绘制了PPT上这个看起来有点奇怪的图（见图6），从中我们可以看到，当前人类社会处在这个点，此时我们有增长有创新且升温了3～4摄氏度的气候危机尚未出现，因此我们不需要转型，这种舒适的形势可以维持二三十年，之后就要改变。为了避免危机，我们要努力转向低碳经济，减少温室气体排放。

图6 五个好消息与五个挑战

第一个好消息是我们做了技术评估，发现需要的低碳技术已经存在或者我们知道如何研发。这一点很重要，因为缺乏技术将无法解决高碳转向低碳的问题。从技术上来说，我们能够解决问题。第二个好消息是我们的资金足够负担这次转型，转型不会使我们陷入金融危机。数据表明我们需要投入大概全球GDP的2%～2.5%，这笔资金的数量不小，但是我们负担得起。第三个好消息是我们观察并研究、收集了资料，发现包括中国在内的很多国家，人们的价值观已经转为可持续发展。20年前在很多国家，绿色发展观念、可持续发展观念是少数派的观念，但是现在形势改变了，人们明白了可持续发展并不是一种奢侈品，这是一种福利，标准和价值观发生了转变。第四个好消息是由于互联网的发展，我们的全球网络可以让我们在全球更快地学习，知识的学习和传递速度比以前快很多。由于我们的时间紧迫，这一点也很重要。第五个好消息是转向低碳会使我们得到很多共同的利益。因为减少温室气体排放也是减少污染，这也关系到健康，关系到新的创新及其应用，关系到新的增长方式。我认为现在世界范围内除了低碳可持续发展之外没有令人信服的增长。但是同时也有很多阻碍和挑战，这里我会重点介绍五个。第一个转型的障碍是路径依赖。我们的社会中存在不同种类的路径依赖，如技术的路径依赖，当前的经济还是由化石能源驱动，这是占统治地位的技术，这种依赖很难改变。需要新的知识、新的技术，需要重建新的系统。除了很强的技术意义上的路径依赖，还有政治意义上的路径依赖，我们的报告中有题为“政治是愚蠢的吗？”的一章，论述了很多高碳行业、公司、部门之间的政治联盟。我们也需要克服这种政治的路径依赖。在个人层面，也有路径依赖。约翰·梅纳德·凯恩斯曾说：“困难不在于产生新观念，而在于背离旧观念。”我们要克服路径依赖，因为过去的250年里，世界上国家的发展都是基于这种不可持续的增长模式，我们需要改变。第二个转型的障碍是时间框架很紧张，这一点我已经谈过。第三个转型的障碍是当前组织全球合作有难度，但是我们需要进行全球协商以达成转型成功。我会在演讲末尾部分详细介绍这一点。第四个转型的障碍是全球迅速的城市化进程。现在城市居民有30亿人，到2050年会达到60亿人。而60%～70%的全球温室气体排放来自城市，如果未来十年我们的经济发展方式不变，而城市人口从30亿人增长到60亿人，那么全球变暖升高就会超过2℃。所以城市化要保证低碳，而且时间紧迫。最后一个转型的障碍是从气候的角度看，很遗憾确实很多国家拥有廉价的煤。煤矿储备很大，我们不会因为煤矿衰竭而走出高碳经济时代。但我们需要转向低碳的经济繁荣。

转型中哪些部门最为重要？答案是我们需要专注于三个最重要的部门以使低碳转型成为可能。第一个是全球能源部门，全球能源部门产生的温室气体排放占全球的70%，所以低碳转型关系到未来如何管理能源部门。第二个是土地使用，因为其温室气体排放占全球的25%。谈到土地使用，有两个重要动力，一是森林，因为森林会吸收温室气体，如果我们砍伐森林，就会有更多的温室气体排放到大气层。所以保护森林很重要。二是农业和农业的组织形式。农业可以是高碳的也可以是低碳的。我会先谈谈农业再接着谈能源，因为在能源的效率提升方面我们已经有所进展。但是在农业方面，过去的20年里碳效率提升一直停滞不前。我们知道如何做，并且也花费不高，但是由于路径依赖，农业的组织方式没有改变。第三个是城市化，前文已经论述了世界范围内的城市化趋势，而其中最重要的地区是亚洲。目前在亚洲有15亿人口居住在城市，到2030年，人口数会达到30亿。在接下来的20年里，在亚洲要建造的城市基础设施会是欧洲自工业革命以来建设的基础设施的2～3倍。由于能源需求大多来自城市，所以关注如何建设低碳城市很重要。

石油还有6600亿～10000亿吨的排放潜力，天然气还有3400亿～5000亿吨的排放潜力，煤还有290000亿～430000亿吨，前文提到在气温上升2摄氏度的预算之内，我们可以排放的温室气体是7500亿吨，我们需要在资源匮乏之前走出化石能源时代，理解这一点很重要。我们探讨在全球视角下能源部门应当采取何种措施转为低碳部门。当前全球能源生产85%的是以化石燃料为基础的，只有15%是非化石燃料。在未来五六十年里我们要实现的是把这个比例颠倒过来。因此，我们要关注再生性能源的投入。这是第一个部分。第二个部分，正如大家在此看到的，如果经济按照以往的方式发展，未来十年的能源需求会大大提高。图7左侧部分是气温上升6摄氏度的地球系统，这是我们要极力避免的。图7右侧部分显示的是升温2摄氏度的地球系统，有两点非常重要，其一是我们要有更多的可再生能源，需要更多的天然气，因为与化石能源（比如煤）相比，天然气的温室气体排放量会大大降低。大家可以从这个场景中看到，能源效率获得提高。这是能源革命的第二个部分，不仅仅关于再生性能源，还有关于提高能源效率的。第二种场景中所需的能源量减少很多因为效率获得了提高。这是能源转型的内容。一方面是新的能源结构，另一方面是更高的能源效率。提到我们拥有这方面的技术，我会向大家展示其中一些技术。图8右侧显示的是沙漠中的电力和能源结构。在欧洲，我们与非洲的伙伴合作在非洲北部沙漠生产可再生的太阳能，少部分传送至欧洲，大部分当然提供给能源匮乏的非洲。图8左侧传达的信息是风车产生能源，中国与德国都是风能的主要国家。可以看到风车发展得很快，德国20世纪90年代的风车，它们的直径只有40～50米，而现在建造的风车直径在180～300米，20年里增长了3.5～5倍。这意味着今天的风能并非缝隙技术，我们正在建设新的系统并深度开发。20～25个大风车就能取代一个核电站，这是一项大技术。在德国，我们要在2022年停止核电，就是用十年时间关闭核电厂。2050年拥有80%的再生性能源，我们会很快地停止使用化石能源。当前，再生性能源占20%，20年前是0%，到2020年会达到40%，2050年达到80%，其中没有核能。所以德国的能源转型非常彻底。中德在这方面应该加强合作，因为这是工业的未来。世界上的很多国家都需要这些新技术，拥有这些技术就能实现飞跃，这是全球经济的下一个创新浪潮。

图7 气温上升6℃和2℃的地球系统

图8 风力发电和沙漠中的电力与能源结构

图9是一张很重要的图表，传递非常乐观的信息。我们提出一个问题：全球能源市场中再生性能源份额需要有多大才能在化石能源时代和再生性能源时代之间为生产成本带来价格收敛。计算之前我们估计全球能源系统中可能需要50%～60%的再生性能源，（经过计算之后）我们发现与此不同，大概20%的再生性能源就能带来能源生产的成本价格收敛，这是很乐观的信号。问题在于，在国际合作的视角下，我们如何构建国际联盟以推进全球能源市场迅速达到这一点。因为，如果你看到在低碳能量载体和高碳能量载体之间价格收敛，这个大的路径依赖就会失效，这是全球低碳转型的转折点。当前我们在全球能源市场有6%的再生性能源，需要达到20%。这是基于技术学习曲线、规模效应提出的这个乐观的数据。

图9 成本价格收敛

图10 德国20世纪70年代建成的房子

我谈到了可利用的技术，这张图片是关于德国的。在德国不是新建城市地区，而是重建已有的城市地区。这里大家看到的是20世纪70年代建成的房子，为了提高能源效率而重建的，能源效率提高了90%，这种技术已经存在。在亚洲的城市化地区，城市人口在增长，问题在于如何建设整个城市。幻灯片中是高碳的图片和低碳的图片。我们要考虑低碳发展的城市规划。在德国和中国，我们能够建造零排放的建筑。德国现有的建筑不但不消耗能源，而且能产生出比所消耗的能源更多的能源。这很重要，因为，迄今为止，全球40%的能源消耗和排放是来自建筑，现在我们能够建造不消耗能源甚至产生能源的房屋，所以房屋可能成为分散化的能源结构，这是令人着迷的技术进步，而中国是这方面市场的一个领导者。同时这也与流动性概念有关，如何减少私人汽车的数量？如何改进公共交通？世界上有很多这方面的典范。

需要再次讨论成本。前文已论述到低碳转型我们有资金负担。不同的国际研究都表明我们需要投入全球GDP的2%～2.5%。高碳经济的和低碳经济的投资周期很相似。但是如果是低碳投资，前期投资要高得多，投资周期的第二阶段会出现有趣的投资节约，而高碳投资，前期投资少得多，但是没有第二阶段的节约。所以，低碳经济关系到前期投资，我们要考虑前期投资的资金。我们研究了如何为必要的前期投资提供资金来源，但同时还有几项重要的论证。当我们谈到投入低碳转型的2%～2.5%的GDP时，我们要认识到这些计算中并不包括全球气候破坏的成本。如果我们的世界升温3～4摄氏度，我们要投入资金应对气候破坏。当前全球经济的化石能源补贴的数量达到5000亿美元，占全球GDP的1.0%～1.5%。我们认为如果把这个高碳补贴转到低碳，就能为低碳转型提供相当大一部分的资金。最后一点同样重要，不仅关于成本，还关于提高投资比例。如果我们需要为低碳转型投入全球GDP的2.5%，就涉及改进投资比例。中国的投资比例很高很好，大家知道，欧洲当前有很多问题，从金融角度看，中国的情况比欧洲好得多。从技术角度看，欧洲、德国还有一些优势，从金融角度看，中国还有很好的实现飞跃的机会。这张幻灯片还蕴涵另一个重要信息，是关于转向低碳的投资结构。我们计算了需要向前述几个部门投资的数量，结果显示，从全球视角来看，有且仅有20%的低碳投资需要用于能源基础设施。我不知道中国对此的讨论具体是如何，在欧洲，关注的是基础设施，其他部分则非常少。但是这里显示的是基础设施只占20%，50%将用于建筑、交通和流动性，15%用于低碳技术创新研发，15%用于土地使用和工业部门。以上是投资组合。能源基础设施是其中的一部分，而能源效率提高则更重要。

现在进入最后一部分。我们来探讨全球低碳经济如何转型。图11中的这条曲线就是我们对于低碳转型的概念化。这里大家看到的是旧的增长模式——高碳、高能耗，现在我们可能处在这一点，需要向上攀升，这并不是线性发展，需要转型和变化。需要调动各种力量以便在这条曲线上向上移动，最后形成低碳社会。我们计算的这段时间需要30～40年。现在我们可能位于反弹路线之上，中国、印度、美国、欧洲，都在提高能源效率、碳效率、资源效率，但是我们的增长超过了能源的效率提升，这是反弹的含义。我们要做的是使这条曲线上移，推动转型规模，因为我们要从低碳试验转向低碳系统，事关加速，事关长期视角，我已谈到愿景，我们需要长期计划，不但要想到部门改革，还要系统改革。想到城市时，不仅关于建筑、交通，而且关于如何使整个城市系统可持续，因此，系统改革绝对必要。

图11 转型策略

现在我说明感到乐观的原因。为了向大家证明当前我们所处的形势可以加速低碳发展，我将对20年前1992年在里约热内卢举行的第一次关于可持续发展的国际会议和当前形势做比较。我会向大家解释1992年里约热内卢会议，当大家读到《21世纪议程》时会发现，1992年全球的政治领袖达成共识，原有的经济发展和增长模式是不可持续的，但是高碳增长模式事实上还在延续。高碳社会是复杂的体系，行业、市场、消费者偏好、政策组织形式、文化和技术，是个一体化的系统。所以尽管政治领袖达成共识，这种高碳增长模式不可持续，需要改变，但是事实上一切还在延续。当时的绿色发展思想家、绿色发展政治家、绿色发展公司和领导者，是先行者，20年前绿色发展观念和可持续发展观念是属于少数派的，不能推动经济发展或政治决策。今天的情况大不相同。从政治家认同原有方式不可持续到增长方式转型并不是容易的事，因为转型需要新的模式，需要增加低碳投入。从高碳社会转型到低碳社会，我们需要在图12中的曲线上向上攀升，这里有五个主要的竞技场要出现全球低碳转型。在我介绍这五个竞技场之前，我会先介绍这条曲线的起点和终点，来解释为什么低碳转型已经发生。这是1992年，政治领袖在里约热内卢提出人类在高碳的前景下不能前进，需要改变，但是当时没有解决办法。《21世纪议程》是一个250页的文件，国际会议的文件如果只有250页，就代表人们不知道如何解决问题。有很多问题，但是不知道如何应对可持续发展的危机。现在我们的情况好得多，我认为，我们拥有愿景，有想法，我们的研究试图为解决这个问题的思路做出贡献。我们拥有更多关于投资的知识，知道如何去做。下面我来介绍全球低碳转型需要出现的几个基础因素。第一个是参与者，我们的研究证明已经有很多经济体，如中国、欧洲和其他国家，越来越多地参与转向低碳发展。中国的“十二五”规划非常重视绿色发展和低碳发展。这些都是很重要的动力，参与者的数量比几年前大有提高。在德国，20家最大的公司邀请我们给它们做这个研究的报告，而20年前，没有一家公司会这样做，这表明，公司已经意识到增长动力已经改变，它们不能躲避而是要参与这个转变。现在确实已经有很多公司转向新的增长观念、发展观念，明天我会与中国环境与发展国际合作委员会会面，我已经在这个咨询委员会工作了5年，这次我们要研究的是生态文明和中国低碳经济的形势。中国在这方面的探索已经开始并逐步深入。OECD国家提出了超越燃料增长的福利的观念，这是与旧的发展模式不同的。第二个是政策体制。比较一下同一国家1992年推动经济发展的政策体制与2010年的政策体制，我们发现政策体制逐步转向可持续发展导向，也许并没有我们期望的那么快，但是全球范围内政策体制的确在改变，而且我们知道如何去做。20年前，我们不知道如何描述宏观经济的可持续发展，而现在可以。第三个是国际环境，事实上这是转型中最重要的部分。许多国家都已经取得了很多进展，但是国际合作还不够，气候谈判进展太慢，无法达到2摄氏度的目标。我已经介绍了，在国家层面已经取得很大进展，我在此倡议成立一个低碳开拓者联盟，朝着低碳方向发展的国家会更好地合作。我想，中国、德国、欧盟、美国的部分地区应与其他国家合作，帮助它们更快地实现低碳发展。我们建议德国政府与中国政府协商，共同投资，大规模培训下一代低碳建筑师、工程师、经济学家、交通专家。中国学生在中国和德国学习，德国学生先在德国学习，然后来中国，来展示中德两国在全球转型过程中在应对临界点方面的努力。

图12 从高碳社会转型到低碳社会

图13 推动低碳转型的三个重要机制

现在我们来看最后一张幻灯片（见图13）。有三个重要机制推动低碳进程。第一个重要机制是关于共同演进，这意味着这个进程不是你能够掌控的，确实有低碳的政策，有创新标准和探索，这些方面相互作用并且彼此巩固。大的技术创新、标准和价值观的转变，将使政策改革更加容易；另外，由于不同方面都出现了低碳趋势，使得参与者的数量增长，动力相互巩固。第二个重要机制是转型政策，这些政策的目的不仅仅是提高能源效率，还要组织转型变化以帮助人类在这条曲线上向上攀升，这是我明天要去参加的中国环境与发展国际合作委员会年会关注的问题，不只是能源效率导向的政策，而且是转型政策，我们的报告中也收录了我们认为的转型政策。最后一个能够使得这次转型成为可能的重要机制是基于我们对于可持续发展社会契约的思考，社会契约这一术语是从欧洲著名思想家卢梭、康德、休谟那里借用而来的。在大约250年前他们所处的时代，他们思考了向工业社会的转型，向人权、个人权利、公民权利的启蒙时期发展。他们在著作中提出，社会的这种变化只有在政治参与者之间、社会之间、私人部门之间出现社会契约的情况下才能实现。因此我们借用社会契约这一概念。显然，社会契约与我之前谈到的愿景有关，即可持续发展的社会契约。例如，我们在报告中论证，奴隶制的废除、童工制度的废除，都以社会契约为基础。这意味着，低碳转型不仅仅是政策、工具和刺激措施驱动的。为了实现转型，要以政策为基础，同时我们还需要可持续发展的社会契约。我认为中国关于生态文明的想法，以及如何平衡人类的发展与稳定大气系统，都是向这一方向的努力。以上是推动低碳转型的三个重要机制。

感谢各位的耐心，这是很长的一次讲座，大概90分钟，希望大家会觉得讲座中有值得讨论的思想。谢谢！

潘家华：非常感谢你，Dirk。这是非常有益的一课。教授给予我们一堂极富价值的关于全球向低碳经济转型的讲座。每个人都知道，我们拥有许多技术，但将其扩展至地球的疆界来考虑依旧超越了我们的想象。我们拥有这些技术来提高我们的福利，但这些地球的疆界问题使我们陷入窘境。同时，教授强调，我们必须具备一些驱动力遵循共同演化路径向低碳经济发展。最终，我们必然走向零碳经济。我认为教授所说的必然成真。在工业革命之前，确实存在零碳排放。所有的能源来自自然资源，且循环再生。也许100年后，当所有的化石燃料将被取代，我们最终将达到低碳排放。这的确是必然的，同时教授已经阐明，我们所拥有的机会且面临的挑战。德国和中国正在进行努力，我们在这些问题上已经取得了巨大的进步。近年来，在组织层面，存在着缺乏国际合作精神的现象。但这并不重要，只要我们继续前进，必将会有解决方案。

我想这简短的90分钟演讲，包含了上述的信息和知识。我相信我们享受这个过程的同时，学到了很多。但我们仍想了解更多，希望提出一些问题与教授探讨。这些问题是开放性的，任何人有任何问题、任何发现或任何评论都可以提出。我相信教授会很乐意与大家讨论。如果大家在英语表述上有障碍，当然，这是可以理解的，毕竟英语不是我们的母语。你可以用中文，然后我帮你把信息转达给教授，所以不用担心。如果你使用英语，自然最好；如果你使用中文，也不会有问题。因此，交流是开放的，任何人有任何问题皆可。

学生甲：首先，非常感谢教授，非常感谢您的演讲。我有一个问题。您提到未来的地球温室气体排放碳预算是750 Gtons。我在潘教授的建议下做了一些碳预算的提案工作。基于我的计算，这个数字相对于现实过于保守。您知道一些自然科学家计算出这个值为1000 Gtons，或更高的1400 Gtons。您知道在未来10～20年，没有基础技术和政策支持，我认为750 Gtons是不可能的。那么对于这个问题您有什么看法？还有，关于未来低碳转型的碳预算方案您有什么看法？这是我的问题。谢谢您！

迪尔克·梅斯纳：首先非常感谢你的提问。据我所知，潘教授和他的团队也在研究碳预算有关的问题。就这个问题，我们在两三年前的哥本哈根，已经和国际听众进行了全面讨论。这次我们的重点在于使气候谈判可行，并推动气候谈判取得进展。我们需要将我们的2摄氏度目标转化为更多实实在在的东西。这个有形的东西是指温室气体排放量。我们需要减少温室气体的排放量，而且我们需要知道预算实际上有多大。而这正是我们努力所需要做到的。

关于如何分配预算，这是一个司法问题。司法问题是非常重要的。而我们所关注的是现在有多少Gtons可用，我们通过计算自然科学家给出的数据，得出未来四十年750 Gtons和2摄氏度目标兼容的可能性达到67%。如果你把可能性降到50%，我们可以做到这一点，当然，这是一个高风险的游戏。如果你这样做，我们最高可把结果估至1200 Gtons。转型仍然是个挑战。这样更为容易，但你将面临更高的风险。更高的风险意味着接下来可能升温3摄氏度。当然，我们在中国和全球范围内的投资将会有更高的风险。所以我们需要权衡。它关乎风险，是一个概率性问题。它关乎我们认为转型的速率。无论事实怎样，到21世纪下半叶，温室气体的预算将会非常小。在你我的计算中，我们讨论的200 Gtons或300 Gtons是关乎于21世纪下半叶的。因此在下一个40～50年，它需要通过一条非常激进的途径来降低我们的碳排放量。我们所思考的是从技术层面上的演示，这是基于我们现在所知道的与所能做到的。从财务的角度看，它是可能的。我想补充一点，现在各个国家才是该过程的先驱，需要注意在这一过程中积累经济优势。

潘家华：好的，谢谢你。我认为这是出于安全角度。严谨的预算将确保2摄氏度目标，如果我们不拥有更严格的预算，这将意味着运行风险非常高。

学生乙：谢谢您的演讲。我想知道您对绿色增长转型的看法，因为有些人认为绿色增长是一种幻想。我们需要发达国家在法律上的部分妥协，以此给予发展中国家增长机会。所以我想了解，也许是过去我们所相信的，即维持经济增长就是确保一切。我想知道您对于这种增长的观点，同时结合您的大转型观点进行阐述。

迪尔克·梅斯纳：非常感谢你的这个问题，这是一个非常重要的事情，也是一个很难回答的问题。两周前，我们与德国的丹尼斯·梅多斯（Dennis Meadows）开了一个会议。我不知道你是否知道他的名字。丹尼斯·梅多斯是《增长的极限》的作者。他是个70岁的老先生。40年前，也就是1972年，他写了一份《增长的极限》研讨会工作记录。作为第一位真正专注于此类问题的科学家，他提到“想象一个拥有日益增长人口的世界变得越来越富裕并永远发展”。同时，他的回答是“我认为这是不可能的”。我的答案与他的有一些不同。我认为世界上仍然存在一天收入低于2美元的人。所以发展对于他们来说，财富的创造是必然的。在这个社会上，我们确实存在一些年收入在1500～3000或4000美元之间的人群，仅仅通过有组织的地区性分配来调节并不足够。因此，贫穷国家的增长仍然是绝对必要的。但我们需要做的是，通过控制碳排放相关自然资源的使用来调节这种增长。这是我们所面临的挑战，需要思考这样操作的可能性。我认为对于我们较为富裕的工业化社会，情况有所不同。在这种社会，人们对于一定水平增长的依赖逐渐减小。你可能知道，德国的人均年收入大约是35000欧元。他们并不显得比月收入2000～3000美元的人更为富裕或更为幸运。因此，对于高收入水平国家，增长的问题不同于贫穷国家，重要的是低碳方面的挑战。我们有很多部门不消耗原材料。这是我们所需要分享的增长模式。

潘家华：这也是一种度量方法。如果我们用GDP或者货币计量，这里所显示的收入实际上只是一种指示。这并不能表示更多的钱意味着更多的幸福和更高的福利水平。举个例子，如果生活方式是不健康的，你吃的太多，你喝的太多，也不锻炼身体，之后你就需要吃很多药。你吃了很多药，产生大量的GDP。这是资源的浪费。所以生活方式是非常重要的，我们需要的是生活的质量而不是物质上的满足。我们可以有无数的财富，但最后你不享受你的生活，没有一个很健康有品质的生活方式也没用。因此，更重要的是幸福，幸福不是由你的收入和财富的数量来决定的。

学生丙：谢谢您的精彩演讲。我的问题是清洁发展机制增加了一种美妙的方式来解决发展中国家与发达国家之间的碳交易问题。但其中也存在一些不同的声音。我的问题是您如何看待这个CDM系统？谢谢您。

迪尔克·梅斯纳：从我的角度来看，该机制很重要。主要由于美国与德国的碳公司通过对发展中国家低碳技术的投资来降低碳排放。我们可以把这个转化入CDM机制，同时转化为转移技术和财政资源。如果你观察基于CDM机制的投资量，这个量与前期投资相比是非常小的。因此，CDM是重要的，但不足以驱动全球变革。私人投资和大型发展银行的巨额投资相比更为重要。清洁发展机制仅是大故事中的一个小元素。

潘家华：我认为你当然是对的。CDM是在欠发达国家中一种减少排放成本的机制，是用来帮助发展中国家的低碳发展的。所以它是有一定的正面影响的，但是从长远角度看，资源的数量是有限的。这就是我们一直保持高额财政投资的原因。这也是教授建议的私人部门介入的原因。当然，CDM是由私人部门介入的，但是这个迹象是十分重要的。你知道，CDM项目在过去的几年内推进了中国等存在再生能源的国家的发展。所以CDM对市场信号是有重要影响的。

学生丁：非常感谢您精彩的演讲。近年来低碳经济是非常火的，请问您对中国低碳工业的看法是什么，在下一个十年当中什么因素将会成为主导因素？

潘家华：这是一个不小的问题。

迪尔克·梅斯纳：这是一个大问题。我们将尝试在年会上回答。在此，我将面向三个非常重要的方面进行探讨，并且你享有优先权。第一，中国是新兴中产阶级与城市化趋势相结合的国家。这在全世界范围内来说是非常强势的。所以，在中国，在建设低碳城市方面做出成果是非常重要的。中国是这一领域的先驱者。这是非常重要的一个领域，覆盖了城市化、低碳城市、低碳城市化这三个部分。第二个非常重要的领域就是能源领域，因为就如同潘教授所讲，中国的能源消耗持续在增加。在低碳能源方面，中国在数量上来说是做得最大的。德国是该领域的第二大投资者，所以说能源是非常重要的一块。最近的数据显示，中国在能源利用率方面有着非常大的进步，但是在低碳方面不尽如人意。在中国，能源依然是大比例依赖于化石燃料的，所以朝着可再生能源发展是非常重要的。我的最后一个观点就是，中国的投资比例非常高，40%的GDP都用来投资了。德国的投资比例大概在23%。这说明了中国在重建经济设计上面相比大部分国家而言是快得多的，你们可以令转型速度更快。所以问题就是，是否所有的投资都是按部就班地朝着低碳方向前进的。这是我必须要提出的第三点。

潘家华：低碳转型的成本很明显并不是小数目，但是从另一方面我们必须改变我们心态。它不仅一个机会，这些投资将会带来能源安全，同时将会产生一系列的工作岗位。这将大大驱动经济的发展，并且将会提高工作待遇。剩下的不长的时间内，大家还可以提最后一到两个问题。

学生戊：谢谢教授。在您的演讲中，您提到了国际上对于2摄氏度的共识。所以我能不能请您说明一下如果地球的生态系统达到了那个2摄氏度临界点会有哪些后果？您知道，凡事有利有弊，所以能否请您详细地讲一讲？谢谢。

潘家华：好的，那就更多了。我们可以挑选其中一到两个讨论。这是最后一个问题。

迪尔克·梅斯纳：非常感谢在场的各位提出的所有的问题。接下来我会把我的想法陈述一下。我认为，我们的确是有机会决定三种大转型方式的。不管怎么说，我们都在往大转型的方向走。我已经就低碳的话题讨论过了。低碳转型正在试图避免这些风险。如果你想要3度甚至4度的改变，我们就需要通过二次转型的手段。但是大多数的自然科学家都表示，气温提升3至4度的高额风险来自对水和土地的获取，来自天气，甚至来自更高的临界点。因为可以想象，21世纪末季风将会消失，我们并不知道接下来要面临的是什么。我们无法想象一个没有季风的世界是什么样，所以风险是非常高的。这是第二种可能性。我们正朝向全球变暖迈进，必须适应地球气候的变化。这是一个非常大的转变，并且这与大转型有很大的关系。近年来如何寻找解决的办法正在讨论当中。上个月，我在美国讨论过这个问题。我在不同的大学做了相似的报告，在华盛顿为智囊团做了报告，其中最重要的讨论项目就是这个研究。这是地球工程学的问题。它是一门关于讨论地球是否变暖，怎样为地球人工降温的学科。人工降温的成本和风险都是未知的。人们都表示这件事太难了，太具有挑战性了，他们希望走地球工程学这条路。我会尽量避免走这条路，因为始终是可能通过转型来实现低碳的。我们知道该如何进行工业设计。我们掌握着技术，我们也知道相关政策。为什么我们要走地球工程学这一条隐含着人为重新构筑全球生态结构的路呢？我对于这件事情持否定态度。我是说，这是有困难的。让190多个国家制定一个关于气候的政策是非常困难的。如果我们要走地球工程学这条路，我们需要在全球范围内讨论很多事情。举个例子，如果我们把化学剂加入海中来测试大海对于温室气体的容量，谁可以被允许这么做呢？我们应当把多少化学剂加入海中？或者我们把化学剂洒入大气层中来降温，这又是谁可以决定的？这种做法的可用性是多少，谁又该对此负责？所以我们需要对地球工程学提出一个国际标准。如果没有这个东西，很明显会引起国际争端。我认为，地球工程学这条路主要是解决什么是该避免的这个问题。我要对气温的大转型提出一些观点。二次转型引起的一个更高温度的世界的风险是非常高的。当大家看到我指出的这些要点的时候会发现，这些并不是地球的小事件。这些对于全球的系统都是大事故，我们也并不知道该做什么去应对它们。我们并不知道以后地球的生态系统会变成什么样。我们和全球很多的科研院所一样，都对亚马逊进行过研究，结果指出，由于3.5～4度的全球气温上升，亚马逊森林消失的可能性是非常大的。我们现在模拟不了的就是拉丁美洲的水和土壤系统会变成什么样。我们可能在整个地区陷入食物危机。所以我希望避免这一切的发生。我们都知道可持续转型，让我们朝着这个方向前进。

潘家华：非常好。人类是非常具有创造力的，但是有时候这些能力会用在错误的地方，如核工业。当然，核工业确实带给人类很多好处，但是最终我们并不确定它带给我们的究竟是什么。这是一个例子。教授还提到了地球工程学。很少有科学家支持这个提案，这意味着我们必须要干涉自然，人工地改变自然循环的趋势。他举了一个例子，就是把化学物质放入海洋，让所有的二氧化碳都被海洋吸收。还有一些科学家提议把飞机送入太空向大气层喷洒某种叫气溶胶的物质，用来减少地球收到的热辐射。其实从成本来说并没有多高，但是风险有多高是未知的。并且有一件事情很明白，那就是我们必须尽量减少人类对大自然的干预。这也是一种精神力，一种文明的观点的改变。因为在党的文件中已经明确标注出了，这叫生态文明。这和工业文明是截然不同的。在工业文明下，人类拥有统治权，我们可以征服自然，人们的价值观非常简单，那就是利润最大化。但是在生态文明下，事情变得有点不一样。在伦理上，不一样的是，我们尊重自然，我们和自然一起成长、一起生活。我们必须和大自然和谐相处。我们珍视的东西并不是追求利润最大化，而是对生活质量的追求。我们追求的是生活的质量，并不是金钱。对于每个人来说，生命是有限的。世界上并没有长生不老药。日本人的年龄期望值是全世界最高的，有些甚至达到了93岁。能够活过100岁的人微乎其微。所以生活的质量对于每个人而言都是非常重要的，对下一代也是。我们需要一些文明的转变、文明的观点。不然，我们的技术不会提高我们生活的品质。技术确实非常重要，但更重要的是我们需要有文明的观点。

我从教授的鼓舞人心的、启人心智的演讲中学到了很多，收获了很多。并且，私下观点的交流似乎也是硕果颇丰的。我必须说，教授的研究所也是世界上著名的智库。教授邀请了很多博士后学者去他的研究所进行研究。他和很多大学有合作，并且有着一些学术交流和联合研究的机会。这是一个不算大的世界。在地理上来讲，中国和德国有点儿远，但是在现代交通运输的技术和互联网技术的支持下，整个世界并没有那么遥不可及。我们可以齐心协力地一起做事。我建议你们和教授保持联系，并且我相信研究生院拥有继续联系的方式。让我们一起感谢教授的精彩演讲！谢谢你们的参加。

原文

Dirk Messner：And now，before I do so，I would like to explain to you what this acronym is —WBGU is meaning.This is the Germany Advisory Council on Global Change.So this is my second job to say，so I am the direct of German Development Institute located in the west part of Germany.At the same time，I am the vice-chair of the German Advisory Council on Global Change.This Germany Advisory Council on Global Change works together or works is based on corporation between 9 important institutions in Germany which work in the field of global challenges and global sustainable development.So there are 9 directors and 9 institutions together，we do advice for the German government.We are the climate advisors to the government.We work on energy issues，and other important global change dynamics.For example，the urbanization is one of our most important issues that we are current focusing on.The issue I am going to talk about to you today is about the great transformation towards a （global） low carbon economy.The lecture which I am giving is based on the study，a comprehensive study，which is titled World in Transition：Social Contract for Sustainability，so what I am talking about now is being written down on 450 pages in this report.It was the contribution of the German academic community towards Rio，2012.We will remember the great and big international conference in Rio，which has been focusing on green development and sustainable development.So this has been German contribution to Rio.For those you are interested to get one of these books，please give the names if this is fine with you，Pan Jinhua.Give the name to professor Pan，and all of you will get the report，if you are interested in this.We can organize this afterwards.

OK.So let’s start.I have organized my lecture for the next one，one and half hour around four big issues.The first issue I am going to concentrate on is the low carbon transformation.How fast do we need this kind of low carbon transformation from a global perspective？And why do we call it a great transformation？Because you have seen that I have talked the title about the great transformation towards low carbon economy.So how fast and why great transformation.Then I will go on to our second issue and I will ask the question whether we can manage this kind of transformation and how we can solve the problems. And I will come up with 5 good news.So 5 drivers of the transformation which we see already in place.But we also focus on 5 major challenges and barriers，because it is a difficult transformation and we also need to know the barriers in order to be not too naive when we drive the this transformation forward.The third issue here is the question which sector are the most important one in our economy when we reflect on the global transformation towards low carbon.I will focus on energy，on urbanization and on land use.Then the forth point is about the major drivers of the low carbon transformation.It is about core revolutionary processes.It is about tipping point the global economy towards low carbon development. And it is about something which we called a social contract for sustainability.So this is what I am going to talk about. And for all of those who are interested in all this kind of slides，the book is available.I will send to you afterward，if you are interested.

So let’s start with the question great transformation，global transformation how fast.My first sight here is about why we need a global low carbon transformation. And I got a citation here form Michael Spence.Michael Spence is an American U.S economist.He got a Nobel economy award several years ago，and in the World Bank conference one and a half years ago，he stated the following：“We simply cannot scale up existing growth patterns in the global new economy.” I think this is exactly what we have to need in mind we simply cannot scale up for physical reasons the existing growth patterns in the new global economy. And why isn’t it impossible？It is because that we are going to be 9 billion people in 2050.We are going to triple the global GDP from US$60 trillion in 2010 to US$180 trillion in 2030 to 2040.We do have huge growing middle classes in global economy.If these new global middle classes go the business as usual growth pattern and consumption pattern，we will not be able to organize the sustainability in the global context.Regarding to the global middle classes，I would like to ask you to look at this diagram here，this table on the right side. And the data are showing the following.I will give the data for the global middle classes in 1990（it was not here on the graph，but I will give you the numbers in 1990），now the current situation，then towards the 2030.So global middle classes，these are people defined by United Nations statistics，with a per-capital income between US$4000 and US$40000.So if you look at the group into the global economy，in 1990，only twenty years ago，1.3 billion people belonging to the middle classes，80% of those living in OECD countries in western industrialized countries.Only 20% of those global middle classes living in non-western countries.So have a look at the numbers in 2009.This is a current situation more or less.What you can see here is that now we do have 1.8 billion global middle classes in the global economy，50% of these 1.8 billion people are still living in OECD countries，but 50% are already living in non-OECD countries.This is very good，because this implies that non-OECD countries，developing countries are now developing fast，and are growing.So the income is growing，which is very good.But from the perspective of sustainability，of course，this implies this new growth which is emerging now driven by the new global middle classes needs to be sustainable.If we go business as usual，high carbon，high resource-intensive，we will not sustain in the planet boundaries.If you look towards 2030，this is not so far away.When I am looking at the auditorium here，most of you are in the twenties and earlier thirties，this is much part of your future，2030. And 2030，we will have，as you can see here，around 4.8 billion people call global middle class people.More or less 5 billion people.Are 80% of them will be living in the non- OECD countries.Only 20% of those will be living in the OECD countries.This is a huge shift.From eighty twenty OECD countries middle class people non-OECD countries middle class people only 20 years ago to 2030 at time at which 80%，now the new global middle classes people will live beyond OECD.This is a huge shift.The global economy is changing radically.From the sustainability perspective，this is very important，because this implies that the formula which we have been used in Rio one in 1992，you might remember，this was a very big conference on sustainable development 20 years ago.The idea in 1992 was that the OECD countries actually they can solve the sustainable issues，and afterwards non-OECD countries can copy that.The situation is different now，because the growth is coming from the non-OECD countries.The global middle classes are living in non-OECD countries now in their majority.This implies that OECD countries and emerging economy，emerging powers，like China，India，Brazil，and South Africa.At the same time in parallel，we need to move towards a global sustainable economy，a low carbon economy.Because if we would see，these new middle classes are growing up based on high carbon growth，we are not able to limit global warming by 2 degree，which is the target we all agreed on international carbon negotiation.So this is why we need a global low carbon transformation，not only a low carbon transformation in several countries around the world.We need a global low carbon transformation in the major economy around the world，and China is obviously one of the major drivers in this field.

This is the second slide which talks about the global transformation.What you can see here on the left side is a graph which is demonstrating the planetary boundaries—the physical and chemical and biological planetary boundaries.The scientists can explain to us now much better than 15 or 20 years ago，how the space looks like，in which we can organize creation in the global economy.We know the planetary boundaries now.The important challenge for all of us is to develop a growth pattern，to develop a wealth concept within these planetary boundaries.We need to accept these planetary boundaries because those are physical ones.If we move beyond those planetary boundaries，we will run in the second graph in the right side，we will run into several tipping points in the earth system.If we move towards 3 or 4 or even higher degree of global warming，we might see a collapse of monsoon in Asia，a collapse of the Amazon forests in Latin America，and an irreversible trend of melting down of the Greenland ice-shied in the Arctic.Tipping points in the earth system，this implies that if we don’t stay with our wealth concept and our growth pattern，if we don’t stay within the planetary boundaries，we will create during the next decade a new earth system.I think that this point is still not well understood in most of our society，beyond our science communities.When I talk to people，the citizens in my own country，they all understand that global warming is something that we should stop and should try to manage well，but few people understand that if we no move forward our business as usual，what we are doing is we are going to change the basic patterns of earth system as such.This is very strong message.

So these are reasons why we need to organize this global low carbon transformation.What we did here and what I demonstrated with this slide is how much greenhouse gas emissions we still can emit in the global atmosphere，which are still compatible within 2 degree Cels to the global warming target.This is what agreed all because scientists are arguing and natural scientists，climate scientists are arguing that beyond 2 degree Cels，we are running into serious problems.So what does this mean for the global warming budget，for the global greenhouse gas budget？Still available？We are coming up and we have been cooperating this exercise with Professor Pan and also his team to develop a very similar budget approach，so how big is the budget，the greenhouse gas budget，still available for us within these 2 degree Cels corridor.We came up with the number，which tells us between today and 2050 we can still emit as global society：750Gt of greenhouse gases.If we do that，with the probability of 67% we will stay within the 2 degree Cels corridor.You might ask me why aren’t you going with the probability of 100% towards the 2 °C target. And the answer is that if we do this with a 100% complete security just let us say so to move towards the 2 degree Cels，the budget will be so small that we cannot organize the global transformation.So there is also a certain risk，750 Gt.How much is 750Gt？If you would be able to stablize the greenhouse emissions on the current levels，this budget will be exhausted during the next 20 years to come. And this implies that budget is small.The budget in which we need to organize our growth patterns，our wealth concept is small.This is why we talk about a great transformation.It is not an easy thing to do.It is a major structure change which implies for our economy.The next step is that we calculated different peaking years regarding the global greenhouse gas emissions.So we calculated the peaking situation for the greenhouse gas emissions in 2011，the green curve here，in 2015 and 2020. And you can see the following，if we would have peaked in 2011（and we did not as you know），we would have needed to reduce the global emissions each year by 3.7% to stay in 750Gt.3.7% is something which is imaginable.If you have been working on labor productivity，energy efficiency gains，3.7% per year is something we can organize.We have seen this kind of efficiency gains in many other sectors.You，in China，you are a master；you are a pioneer in organizing this kind of efficiency gains.3.7% is possible.What you can see also is that if we would peaked in 2020，so only 8 years’ time，we would need to reduce the greenhouse gas emissions annually by 9%.This is very challenging.It might be impossible.So the important message here is with this slide we are under big time pressure，I would be much less nervous in term of organizing a low carbon transformation，if we would not be under such a high time pressure.You’ve seen that I am very optimistic in terms of technology available，institutions which we need，how to do it，the time pressure is very important.We need to peak during the next year to come.This is why the climate negotiations are so important. And it seems so frustrating because we are not moving rapidly.But on other hand，many economy，the investments in all these areas are improving.China is the most important investor in low carbon technology currently.German is the second.We are two important countries in the process.So peaking is important.When we peak，we are under the time pressure.

So I have been calling this low carbon transformation a great transformation.A great transformation.There are the comparisons，regarding other great transformation in history of human mankind.We have been through the history of human mankind and we argued that this transformation towards a low carbon economy reducing radically greenhouse gas emissions and afterwards，the use of resources during the next decade to come.This new situation，creation of wealth within the planetary boundaries is only comparable to 2 big other great transformations in the history of human mankind. And these two other great transformation are the Neolithic revolution，10000 years ago.You know 10000 years ago，human invented agriculture，we started to build villages，we moved beyond the hunt-and-gather pattern of human civilization.This was the Neolithic Revolution.It was a big shift in human history.In these times，we were only several millions people on earth.Human mankind was small，10000 years ago.The second big great transformation from the global perspective was the Industrial Revolution，Industrial Revolution started more or less 250 years ago.In these days，we have been 1 billion people on the earth from server million to 1 billion people on earth.The second transformation of human mankind was based on the energy revolution，because it was driven by fossil fuel.The agricultural society beforehand has been based on the energy of animals.On the animals and on the energy of us as human being working，the peasants，on the agriculture pattern. And based on burning wood.This was the pre-industrial era.Industrial Revolution was driven by energy revolution.It was driven by fossil fuels.This was the second big transformation in human history. And the third big transformation now is this one.We need to make again an energy transformation，because we need to move out of the fossil driven global energy system.We need to bring the greenhouse gas emissions to a stop.We need to organize our development within the 750Gt budget，within the planetary boundaries.With 9 billion people becoming richer，this is the challenge which we are confronted with during the next decade to come. And as we have been seeing，we are under time pressure.There is one very important difference between this great transformation，the low carbon and sustainability transformation and the other 2 big transformations that we already moved through，the Neolithic revolution and the Industrial revolution.The big difference is that the first 2 big transformations have been evolutions.They have been evolving.No one has been organizing the Neolithic revolution.It emerged.No one has been organizing the Industrial revolution.It came up.Now this，the third transformation，the low carbon sustainability transformation needs to be managed.It needs to be politically guided.We need to make this kind of transformation.We will now run out of high carbon era by evolution.We need to organize it.Policy matters，institutions matter.Incentives are important.This great transformation needs to be manmade.It cannot be evolution driven.It’s need to be manmade.This is a very important difference.

This is the last slide regarding the question why the global transformation and why do I talk about a great transformation.There is a new debate in the global science community. And it is about the era of the anthropocene.It has been driven by Paul Krutzen；some of you might know his name.He is coming from chemistry，so he is natural scientist.If you don’t know his name，you do know what he has been observing is the first scientist on earth，because he has observed the ozone hole in the atmosphere was growing and growing and growing.This is what he got noble prize for.Paul Krutzen and other natural scientists are pushing forward a new debate on sustainable development because they are arguing that we are current in a situation，probably since the end of 20 century，for the last 2 or 3 decades.We are in the situation in which for the first time in the history of the earth system.It is the first time during the 4.5 billion years history of the earth system as such （as we know our history as human mankind，as homo sapien history is only 0.22 million years）.Now we are talking about the earth system era.So for the first time in the earth system era，this is the argument of Paul Krutzen：human mankind is the strongest geological force in the earth’s system as such.This is a very strong argument，because till very recently，what we have been arguing is that the earth system is driven by physics；it’s driven by natural science and laws.We，as human beings，are as a part of that；we are living on the earth.Maybe we are destroying several forests and polluting several oceans，but we cannot influence the dynamic of the earth system as such.This is too big for humans.But the data are telling different stories，you know.Data are telling that since the end of the 20 century，human beings are now the strongest geological force in the earth’s system.This is a very important observation，because this implies that human mankind is now responsible to drive the earth’s system.We are making a new earth’s system，if we move forward business as usual，high carbon and high resource efficient growth.So there are several implications I do have on the right handside：we need to learn，as a global community，to drive the earth’s system.We need to manage the global commons：the oceans，the forests，and the atmosphere.We need institutions for that. And as you know，international corporation.We are struggling with this kind of managing the global commons.So we need norms and values for that.I think we need to understand that to manage the earth’s system，to drive it in a sustainable way；we need to perceive the human mankind as something like world sight.This is one of the consequences.Secondly，we need I already said we need to invents and implements a raise model，a raise concept，a growth pattern for billion people within the limits of the earth’s system. And third，we need to manage very different time scales as human beings.We，as human beings，are not very good in managing long term perspectives.Maybe，you in China，you are better organized in this respect.In western society，short-term is very very strong，in the economy or political system.We need to think long-term because wow we need to reflect on the long-term dynamic of the earth’s system as such and we can change those systems.We can change the dynamic of the earth’s system，so we need to think much more long-term，intergenerational dynamics and intergenerational prosperity，is something we need to have in mind.My hope is that the society with the long culture history.China is obviously one of the societies，may help us to do so，because we need to learn that.We are probably in the era of the anthropocene.

I found this slide you are seeing here only some months ago. And I found it incredibly interesting and this is why I want to show it to you.It is from a US economist，Mr.Fugel，who is now already 93 years I found this slide several month ago and called him.He was 92 years he still works at his university.He got the Nobel Prize for doing research on innovations which do have global impact，and what came out of his kind of research was which something very similar to our thinking：the three big transformations，the Neolithic revolution，the industrial revolution，and afterwards now，the sustainability revolution.So what you can see here is the first big transformation which are already talked about. And what Mr.Fogel，the economist，is demonstrating is the following：we have the Neolithic revolution more or less 10 000 years ago. And what he is showing is that during the next thousands of years to come up with the Neolithic revolution，human mankind had this kind of big innovations which impacted the human mankind as such in the rhythm of more of less 1000 years.So every thousand years，one very big innovation.Human mankind invented cities，mathematics，the agricultural revolution and the printing press.Without the printing press，there is no science；there is no industrial revolution；there is no development.So big innovations in a rhythm of 1000 years.

And then the industrial revolution started.About 250 years ago.What you can see here industrial revolution is being driven by acceleration of innovation processes.Fogel is finding every 30 to 40 years now，very big innovations.Very big innovations.So the industrial revolution has been the acceleration of innovation processes.This is being the second big transformation.

And now the third big transformation，the low carbon transformation，is in front of us. And again we need the acceleration of innovations to make the low carbon transformation within the planetary boundaries，and within this 750Gt budget possible. And the question is whether we will be able to organize those under the global scale.This is what I am moving towards.

We studied many other transformations.We studied the industrial revolution in China which started at the end of 1970s.The acceleration of growth in China and the structural change in China.We studied this structural adjustment program in Latin America in 1990s.We studied the emergence of EU 60 years ago.So transformations which are not big transformations.I said there were only two big transformations beforehand.But relevant significant transformations because we look at drivers for transformation.What can we learn from the past regarding drivers of these kind of transformations？What is driving these kinds of transformations，what is driving these kinds of social and economic changes？And we found four major drivers of transformation.I think these four major drivers are also very important and relevant for the current great transformation to low carbon sustainability.These four drivers are the following：

The first one is vision.Vision for a better future，normative perspectives.If you would like really to change system，now towards a low carbon sustainability，you need to know where to go.You need to be able to describe where you would like to move the old system towards.You need a vision.We have two big and interesting transformations which we discussed in our report here to demonstrate how important visions are.We discussed abolishing slavery driven by vision，100 years ago globally.We described the emerging of EU which was driven by vision also.Visions are important to make great transformations possible.

The second one is very easy to understand.It is about technology.Rapid diffusion of innovations.If now we move to low carbon，we need many of these innovations，low carbon innovations，in many sectors. And the diffusion of the innovations is very important.How to organize this.The IT revolution is one of the revolutions in the past which started 30 years ago，which change so many parts of the system of the global economy.Now we need low carbon and sustainability innovations.

The third driver of transformations are very often crisis.We，as human beings，we start changing patterns when we are confronted with serious challenges because changing patterns and innovation is difficult for societies，for economies，for private firms，for public firms，for us individuals.So being confronted with crisis，we change patterns.We started to reorganize the global financial markets after the crisis，the financial crisis in 2008.So crisis are important drivers of transformation processes.This time，talking about the climate challenge，we need transformation before we drive into serious problems.Because scientists can demonstrate to us that if we run into a 4 degree warmer world，the impact of climate change will be so huge，tipping point the earth’s system that we would have to manage irreversible trends in our natural environment.We might not be able to manage that.We might run to serious international problems.So we have to avoid this third element of transformation.The forth element of transformation is knowledge.If we understand that we do have a problem in our societies，in the global economy，this knowledge can help us to change polices，institutions，incentives，growth patterns.Knowledge driven transformation.What we need to organize now in this global transformation towards low carbon is a transformation pattern based on vision，on technology and on our knowledge.We should avoid the crisis.

So where so we stand in the global low carbon transformations？Because we argued that the low carbon transformation is not starting this morning.It already started in China，in Europe，worldwide，actually several decades ago.It started with these debates on serious resources constrains 30，40 years ago.The discussion is not new where we stand now. And as I said in the beginning，5 major good news and 5 major challenges which we find very important.Let’s start with the good news because to make a transformation，you need to be optimistic，and you need to know where to go.But in order to avoid to be？You should know the barriers and challenges also because there are challenges.There are many win-win constellations but there are also many big challenges.We need to know the challenges also.So let’s start with the good news.The facts are that we show on the left side.I should explain this strange diagram to you.This is something which the physicists in our group have been painting down.What we can see here is that this is the current situation.Our societies are here.We are in a comfortable situation still.We do have a growth.We do have innovation.It is not necessary to change now before because the crisis is still not there，the climate crisis.We are still now have the 3，4 degrees plus.We are at more or less a comfortable situation.We could maintain the situation for the next 2 or 3 decades to come.Then we need to change by crisis.But currently it is not necessary.So we need to organize some efforts to move towards a low carbon society，and reduce the low carbon emissions.Efforts are necessary.

So where we stand？The five good news are following：the first important good news is that we did an energy and technology assessment and we found that the low carbon technologies needed are already there and in place or we know how to develop them.This is very important because you would like to solve a high carbon situation go low carbon but technologies are not there.You cannot solve the problem.Technologically，we cannot solve the problem.This is a very important message.

The second important message is that we can finance the transformation.It would not drive us into a financial crisis when we do this transformation.All the data are demonstrating that we need to invest more or less 2% to 2.5% of the global GDP into the low carbon transformation，to make the transformation possible.2.5% of the global GDP is not a small money.It’s not little money.It is a lot of money.But we can finance 2.5% of the global GDP to make the transformation possible.I will give you a national example from my own background.As you know，we re-unificated the two parts of Germany starting in 1989.During the last 20 years after the unification，we in Germany invested 7% of our national GDP in the reunification process，so in infrastructure and investing in house，in different parts of the re-unificated Germany.We invested several percent in this project.We had a vision.We need to re-unificate our country.We need these investments，so 7%.What we need to do globally is 2.5%.We can finance that.

The third important message is we observed and we did study about that，and we gathered materials about that.We found that in many societies，and China is one of those，the values of people are changing towards sustainability.The green discourse，the sustainability discourse has been a minority discourse 20 years ago in many countries，in most countries.This is different now.People understand that the sustainability issue is not something that is luxury.People understand that it is a part of wellbeing，so there is shift in norms and values.The forth element which we do have in terms of favor factures is that we do have global networks in place，to learn much faster internationally than ever before in human history.This has to do with internet.This has to do with our mail systems.We can learn and diffuse knowledge and our innovation now much faster than ever before.This is very important because we are，as I said，under the time pressure. And the last element here is that if we go towards low carbon，there are many co-benefits because if we reduce greenhouse gas emissions，this is also about reducing pollution，about health，about investing in new innovation areas，about innovation and employment，about new patterns of growth.I think there is currently no other convincing growth story worldwide than the low carbon sustainability story.It’s about a new model economic innovation.So there are many co-benefits.

But there are also barriers and major challenges which we need to know. And I would like to focus on these 5 points here.The first one is the about the path dependencies.What does this mean？In our societies，we do have different types of path dependencies，technology path dependencies，for example.Our economies around the world are currently still based on fossil driven energy systems，so this is the technology that dominance.It is not so easy to change the technological patterns.You need to know how for that.You need to new technology for that.You need to rebuild your systems.Technological path dependencies are very strong.But there are also path dependencies in political sense.We do have one chapter in our report here which is titled Is Politics Stupid？This implies that in a high carbon economy when you start to organize the transformation towards low carbon，you do have many high carbon industries，and firms，and sectors and political coalitions around them，which imply political path dependencies.So we need to overcome the political path dependencies also. And then on the individual level，there are also path dependencies.John Mendes Keynes，who you all might know well，he once wrote down a very important sentence：“It is actually very easy to develop new concepts and ideas.The really difficult thing is to forget the old ones.” We have to overcome this kind of path dependencies，because last 250 years the raise of all our nations is being built on this old development model which is no longer sustainable..We need to change a very successful develop pattern.This is difficult.This is about path dependencies.The time frame is very tight.I already talked about that.This is the second barrier we have to change.The third barriers is that currently global cooperation is very difficult to organize but we need a global transformation process.We need to cooperate much more between our societies to make climate negotiation successful.But we are stuck in many cooperation blocks currently.I will come back to this point at the end of my presentation.Global cooperation is currently difficult.The forth point is rapid urbanization globally.You know that currently 3 billion people are living in the urban areas.In 2050，6 billion people will live in urban areas.Professor Pan and his institute is focusing exactly on this kind of challenge，urbanization challenges. And you also know 60%-70% of global greenhouse gas emissions are coming from cities.Cities are growing.Emissions are coming from these new cities.If we do build business as usual cities for the next decade to come，from 3 billion people living in urban areas to 6 billion people，the development within the 2 degree corridor is absolutely impossible.Urbanization needs to be low carbon，and we are under time pressure. And the last point is that from a climate perspective，it’s very unfortunate that we do have a lot of cheap coal available in many countries.From the climate perspective，this is a huge challenge.We are not running out of the high carbon growth era because we are running out of coal.There is a lot of coal around.But we need to shift towards low carbon prosperity.

So my next step is the question that which are the most important sectors which we need to focus on to make low carbon development possible. And the answer is that there are three major sectors which we need to focus on to make the low carbon transformation possible. And these are the 3 sectors.

Above you see is the global energy sector，which is responsible for 70%，75% of the global greenhouse gas emissions.So the low carbon transformation is about how we organize our energy sectors in the future.The second important sector is land use，because 25% of our global emissions are coming from land use.2 dynamics are important，when I talk about the land use.The first part is the forests.As you know，the forests are absorbing greenhouse gases.If we cut them down and destroy them，more greenhouse gases are coming into the atmosphere.So protecting forests is a part of the land use story.The other part of land use story，which is responsible for 25% of greenhouse gas global emissions is agriculture.How we organize agriculture？We can do agriculture high carbon，and we can do it low carbon.We do it high carbon.I will go into the energy sector in a minute，but I would like to focus on two or three sentences on the agriculture part，because in the energy sector we are making a lot of progresses in terms of energy efficiency gains and even carbon efficiency gains.In the agriculture sector worldwide，carbon efficiency is staying for the past 20 years，no progress at all. And we know how to do it.It’s not even more expensive.It is about path independencies.We don’t change the pattern of organizing agriculture.The last one is urbanization.I already talked about it.I already talked about the huge shift towards urbanization worldwide. And the most important region here when we talk about urbanization.The most important region is Asia.In Asia currently，1.5 billion people are living in the urban areas. And in 2030，so only 20 years to come，3 billion people will live in urban areas in Asia.You are going to build an Asia during the next 20 years，an urban infrastructure which is 2 to 3 times bigger than the urban infrastructure which we have been built in Europe since the industrial revolution，our two world wars included.It is huge.The infrastructure，the urban one which is emerging now in Asia during the next 2 decades to come is really big. And as I said that most of our energy demand is organized in cities.It is so important that we focus on how to build low carbon cities.If we go businesses as usual in this urbanization processes，we cannot solve the climate change.So urbanization is really very important.This is the third sector.

What you can see here is these are the greenhouse gas emissions which are still available globally.So have a look.We do have around 660 to 1000Gt in terms of emission potential in the form of oil.We do have round 340 to 500Gt in the form of natural gas；we do have 29000 to 43000Gt in the form of coal.You might remember that I said in the beginning that what we still can emit to stay within the 2 degree cels target is 750Gt.So this graph is demonstrating that we need to move out of the fossil energy era before scarcity becomes a real issue.This is important to understand.Then let’s have a look at the energy sector for a moment.What need to be done in the energy sector a global perspective to transform the global energy sector into a low carbon energy sector.Currently 85% of our global energy production is being based on fossil fuel.Only 15% based on non-fossil fuel.What we need to achieve during the next 5 to 6 decades，let’s say towards 2070，during the next half century and a bit more，is to turn it exactly around.We can still emit then 15% based on fossil fuels but 85% needs to be non-fossil based in terms of energy carriers.So we need to focus on the investments into renewable energy carriers.This is the first part. And the second part，as you can see here is that this is the businesses as usual development path of the global energy system.We are currently now here.What we can see is that during next decade to come，the energy demand if you go business as usual will grow heavily.This is what Professor Pan said the dynamic in many countries，in China also.The picture on the left side is earth’s system under 6 degree higher.This is what we need to avoid anyway. And the right had side you see the 2 degrees compatible global energy system. And 2 things are very important here.The one thing is which I already said is that we need much more renewable energy in the system and we need to have much more gas in the system because gas is less greenhouse gas in terms than coal for example.This is one perspective.More renewables，more gas. And the other perspective is that as you can see your energy demand on the second scenario is much less higer.So we improve our energy efficiency.This is the second part of energy revolution.It is not only about the renewables，and non-fossil energy carriers，but also about improving radically our energy efficiencies.In this second scenario，we demand much less energy because we improve our energy efficiencies in many sectors，urban sectors，industrial sectors，our consumption patterns.So this is what the energy transformation needs to be about.The new energy structure on one side and improving efficiency on the other side.We argued our report that we do have the technologies for that.I am showing you some of those.What you can see on the right side is the power and energy structure in the desert.In Europe，we call the plan together with partners in Northern Africa to produce renewable energy，solar based energy in the desert of Northern Africa. And part of this will be brought to Europe and the bigger share of it will be used of Africa itself because Africa is still an energy poverty region.So these are new technologies which we can already built up in deserts and the solar energy makes a lot of sense.The left side you can see windmills. And the important message here is that the technology is here and China is a driver in this sector，together with Germany actually.We are the two leading nations when comes to wind energy.What you can see here is that the windmills are developing very very fast.The windmills which you see when you would visit Germany are still the windmills made inform the 1990s.They do have a diameter of around 40 to 50 meters only.The windmills which are building currently in Germany do have a diameter between 180 to 300 meters.It is a 6-time growth within only 20 years. And this implies that windmills today is not a niche technology.We are building up new systems.We are going offshore with this kind of windmills，and 20 or 25 big windmill can substitute one nuclear power station.It’s not a niche.It is a big technology.In Germany as you know，as Professor Pan has already mentioned，we are trying to go out of nuclear power towards 2022.So in 10 years，we close our last nuclear power plant. And in 2050，80% of our energy will be based on renewables，80%.So we will go out of fossil energy very rapidly.Currently，20% of our energy mix is based on renewables.20 years ago，it has been 0%.In 2020，it will be 40%.In 2050，it will be 80% without nuclear energy.So in Germany，we are doing a very radical energy transformation.This afternoon，Professor Pan and myself will talk about this kind of dynamics in Germany，and the big investment in China in this area in the German Embassy because we think that Germany and China should cooperate even more in these sectors because this is the industrial future.These are the technologies.The world needs in many countries these kinds of new technologies.Countries which move forward faster than others will be able to lead.This is the next big innovation way for the global economy.

This is a very important diagram，and it is a very optimistic message.What we did here is the following：we ask the question how big need the share of renewable energies in the global energy market be to see a price convergence between the production cost of fossil energy carriers and the production cost of energy based on renewable energy carriers？We estimate，before we started calculating，that we probably will need 50% to 60% of renewable into the global energy system to see a price convergence.What we found out was different.What we found is that with the share of more or less 20% of renewable energy in the share of the global energy markets，we have already seen a price convergence between the cost for energy production base on fossil fuels and base on renewables.This is a very optimistic signal.The question is from the international cooperation perspective，how can we build a coalition of nations which will be able to push the global energy market rapidly towards this point here because if you would see a price convergence between low carbon energy carriers and high carbon energy carriers.Then one of these big path dependencies will be out of order.Then this would be a tipping point towards a low carbon energy sector worldwide.Currently，we do have 6% in the global sector.We need 20%.So this is based on technological learning curves.This is based on scale effects of driving the scale dimension of technologies into new levels. And we came up with this optimistic data here.

I talked about technologies are available，and there is a picture in Germany.Because I talked about cities，and in Germany，it is not about new urban areas.In Germany，it is about reconstruction in existing urban areas because the German population and the German urban population is not growing.So we need to rebuild our cities.What you can see here is a building has been built in the 70s. And you see the building rebuilt towards energy efficiency with 90% efficiency gains regarding energy consumption.90%，we can do that.It is possible.The technologies are already available.In Asia，in the areas where urbanization trends are pushing forward，and urban population are growing，the question is that how to build an entire cities.The slide shows us the pictures of high carbon and low carbon.We need to think about how urban designs need to look like moving towards low carbon development.In Germany and I think also in China，we now are able to build zero emission buildings.In Germany，we now have the first buildings which do not consume energy.We do have the first buildings which produce more energy than they consume.This is very important because until now，40% of the energy consumption worldwide and the respected emissions are being produced by buildings.Now we are able to build 0 or even plus energy houses.So the problem houses might become a decentralized energy structure.These are fascinating technological advancements，which are emerging internationally. And China is a leader in these markets.

It’s about mobility concept.So how to reduce number of private cars and how to improve public transportation. And there are many examples around the world which can make this kind of progress.So I will skip this slide and move to the next one.

We need to talk about costs again.I said that we can finance the low carbon transformation but server messages are important here.The first message is which I already mentioned：different international studies are all showing that we need to invest around 2.5% of the global GDP to make the transformation possible.So the message is which I would like to discuss with are the followings：when you compare over a whole investments cycle，investments in a high carbon energy system with investments in our low carbon energy systems，let’s say from today to 2050 because this is a cycle of energy investment，40，50 years.Comparing low and high carbon investments over the whole cycle，the investments are very similar.But if you go low carbon，you have much higher upfront investments. And you will see interesting savings in the second part of the investment cycle.If you go high carbon，the upfront investments are lower，but you do not have this kind of savings in the second part of the investment cycle.So going low carbon is about upfront investments.This is important.We need to think how to finance upfront investments.We did a study on that.I do have it in front of me this smaller paper which I brought with me. And for those of you who are interested in，I can send it to you of course.So we reflected it on how to finance this kind of upfront investment which are necessary.But there are several other arguments which we need to have in mind which are important.The first important argument which we need to have it in mind when we talk about this 2.5% of investment into low carbon transformations，we need to know that the costs for climate damages are not involved in this kind of calculation.We all know if we run into a 3 to 4 degrees warmer world，we need to invest a lot of money to manage the damages of global warm.If we balanced the pre-investments and the damages，pre-investments are less expensive than investing in managing the damages of global warming.This is the first important argument to contextualize to pre-investment argument.The second very important argument is that currently we do have the global economy subsidies for fossil energy driven plants.In a magnitude of US$500 billion.This is around 1.0% to 1.5% of global GDP.So we are arguing that if we shift this high carbon subsidies into low carbon investments，we can already finance the important part of low carbon transformation process. And the last point is also very important.It is not only about the cost.It is about rising and increasing the investment ratio.If I say that we need to invest 2.5% of global GDP in low carbon transformation，this is about the investment ratio improvement.Your investment ratio in China is very high and very good.You can finance that anyway.As you know in Europe，we do have many deep problems currently.For us，it is more difficult.You are in much better situation now than we are from a financial perspective.I think that from a technical perspective，we in Europe，and we in Germany still have several advantages here.From the financial perspective，China has great opportunities to realize its leap.There is another important message included in this slide.It is about the structure of investment if we go towards low carbon.These are important numbers.Please have a look.Because we calculated how much do we need to invest in these several sectors I talked about to make the low carbon transformation possible.What you can see is that 20% of low carbon investment from the global perspective，needs to be done in the energy infrastructure.20%，I emphasize only 20% because I don’t know how you discussed this in China.In Europe，the focus is very much on the energy infrastructure and very little on the other components of the low carbon transformation.But this is only 20%because then 50% of the low carbon investments are about investments in buildings，in transport and mobility.This is the urban sector.50% of the investment needs to be done here.15% are needed in low carbon research and development activities.So innovation，investing in innovation because we need to improve technologies. And 15% need to be done in land use and industrial sectors.So this is the investment mix needed from a global perspective when we move towards low carbon.Energy is a part of the system of the energy infrastructure，but the energy efficiency part in buildings，transport，mobility and industrial sectors is much more important than the actual energy infrastructure.This is very important to have in mind.

So I’m moving to the end，into the last part of my lecture.I would like to visualize a bit how we conceptualize the transformation towards a global low carbon economy. And this curve here，this diagram，is how we conceptualize the low carbon transformation.You can see here our old growth pattern，which is high carbon，high resource-intensive. And we are probably globally here and we need to climb this curve up.It is not a linear development.We need transformation of change，great transformation.We need to mobilize efforts to move this curve up，to move towards a low carbon society at the end of the day.We calculated this is a period of 30 to 40 years，3 to 4 decades.We are currently probably on this yellow path，the rebound path.In all of our societies，in China，in India，and the U.S，in Europe，we are improve currently energy efficiency，carbon efficiency，resource efficiency，but we are always compensating all our societies currently.We are all compensating the efficiency rates by growth. And this implies what rebound is about.So，in relative terms，we have energy efficiency gains；in absolute terms，the emissions are still rising.What we need to organize is to move this curve up. And driving the transformation，this is about scale because we need to move from low carbon pilots to low carbon systems.It is about acceleration of the low carbon process.It is about a long-term perspective.I already talked about vision.We need long-term plans to make this transformation possible.It cannot be step by step without any vision about the future. And we need to have in mind not only sector reforms，but system reforms.When we focus on cities，it is not only about buildings；it is not only about transport.It is not only how we organize our cities regarding work and our private living.It is the whole system of urban areas.How to make those sustainable.System reforms are absolutely necessary.

I will tell you why I am optimistic and why I think that we can make this. And we can drive this curve up. And I do so comparing the situation 20 years ago，first Rio conference in 1992 on sustainable development with the current situation.To demonstrate to you that we are currently in a situation in which we can accelerate the low carbon development path.So this is the situation in 1992 Rio conference.I would explain what it is about is not self-evident.It is the real conference in 1992.So I will explain to you what I have in mind when I look at this curve.So in 1992 in Rio，there was a consensus when you read the Rio Agenda 21between our political leaders worldwide that the old business as usual development and growth pattern is not sustainable.There was a consensus there.Leaders signed that from around the world.But at the same time，the high carbon growth patterns，the high carbon societies actually moved forward.The high carbon societies are complex systems.It is about industries；it is about markets and users preference；it is about how science organized or policies are organized；it is about culture and it is about technologies.It is a integrate system.So political leaders signed in 1992 that this growth pattern cannot move forward any longer.We need to change.But in reality，things moved forward.In reality，in 1992，the green development thinkers，and the green development political leaders，and the green development managers and firms have been pioneers of green development.The green discourse and sustainable discourse 20 years ago was minority discourse.It was not the discourse which really drove private investment，which really drove political decisions at the level of our governments.The old system for the first year after 1992 moved forward.This was the situation in 1992.The discourse about green and sustainable development was a minority discourse.The situation today is different. And I would like to explain to you why I am optimistic.If you would like to move from a situation which we had in 1992 when political decision-makers argued in Rio that we do have a problem there.We need to move toward a sustainable growth pattern.To transformation is not as easy because you，for a transformation，you need to organize a new model.You need to gain importance，and you need to grow the low carbon investment towards a dominant growth pattern.We have been far away from these transformations only 20 years ago. And the current situation，we are much better off，and I would explain the current situation with this graph here.You see，the curve from high carbon growth pattern to the low carbon society，we need to climb this curve to move towards a low carbon society. And I do have here 5 major arenas where the global transformation towards low carbon needs to take place.5 major arenas.I will I go through these 5 major arenas in a second.Before I do so，I will start with the beginning of the curve and the end of the curve to explain to you why the situation is changing towards a low carbon transformation already.This is the situation in 1992.We had a legitimacy problem with the old development model because in 1992 people argued，leaders argued in Rio that we cannot move forward high efficiency oriented and high carbon growth based.We need to change that.But in 1992 there was no concept at all how to solve the problem.When you read the Agenda 21，which has been signed in Rio.It is a 250 pages document.If you get a 250 pages document on an international conference，this implies that people have not understood how to solve the problem.Many many problems abd many many issues there，but no concept how to manage the sustainability crisis.We are now in a much better situation.I think we do have a vision，and we do have concepts how to solve the problem.Our study tries to contribute to this kind of concepts.Professor Pan and his team，you are contributing to a discussion about how a low carbon economy can look like.We know much more about how to invest.We know much more about how to do it.We know much more about technologies needed.So we have been in the situation 20 years ago and what we saw we cannot go further business as usual but we know how to solve the problem.Now we have concepts around，this is very important.So let me move through these 5 areas and arenas where low carbon transformation needs to take place.The first arena is the arena of actors and what we try to demonstrate in our study is that we now see in many economies.This is real for China，this is real for Europe；this is real for many other countries.We can see that in numbers of actors which are moving towards sustainable development and low carbon development is rising and growing exponentially.Low carbon firms，low carbon cities，governments which focus on low carbon private and public investment infrastructures.The 12th fifth-year-plan in Chinese government is focusing strongly on green development and on low carbon development.These are all very important dynamics.The number of actors is about power，I said it’s about politics.The number of actors investing in these areas is much bigger now than only a few years ago.I can tell you that in Germany what is remarkable is following observation.We have been presenting our study here on the transformation towards a global low carbon economy.In all the 20 biggest companies of the German industry，in all of them，they invited us.10 years ago none of these companies would have invite us to give a discourse on this kind of transformation. And this implies that companies are understanding that the growth dynamics is already changing，and they need to drive the curve instead of shying away.So the number of actors is growing dynamically.Green innovations here on the right side，I already argued that I am very optimistic in terms of technology towards low carbon.So I do not need to elaboraste more on that.Shifting norms and values are heuristics.We do have many actors and institutions now which move forward new rouse concepts，development concepts and growth concepts.Tomorrow I will meet China Council International Cooperation Environment and Development.I am working in this advisory body to your government for 5 years already now. And in this contact，we have been worked about what might an ecological civilization be about；how might low carbon development in China look like.So in China，new development is already emerging and becoming stronger.The OECD，the organization which represents all the industrialize nations，has been developed a concept about wellbeing beyond fuel growth concepts.This is different from the old development minds.I am coming back from Washington last week talking about this kind of issue also.The world is now developing green，growth and development concepts.So there is a big shift in terms of new development which are becoming stronger in many countries.Policy regimes.In our study we compare policy regimes which drive our economies in 1992 with policy regime in the same countries in 2010. And we see is that policy regimes are shifting step by step towards sustainability oriented policy regimes.Not as fast as we would like to see it，not accelerating on a path which we would like to observe，but the policy regimes are shifting internationally. And we know how to do this.20 years ago，we did not know how to describe sustainability，macroeconomic framework for sustainable development，but now we can do that.

The last one here is the international context.Actually this is the weakest part of the whole change.We are making progress in many countries in this for other areas which I already mentioned.In international cooperation，we are not strong enough.The climate negotiations are too slow to really achieve the 2 degrees Cels target.We are making much more progress on national levels as I demonstrated here.What I would like to educate for，and this is the last part of my presentation，is building up a club low carbon pioneers.So countries which move forward toward low carbon direction，we should cooperate in a much more elaborate way compared with the current situation.I could image that China，Germany and Europe，and parts of the U S cooperate another countries，cooperate in important low carbon eras to move forward more rapidly.We suggested to our government to discuss with the Chinese government to make a joint investment in the training，academic training of the next generation of low carbon architects，of low carbon engineers，of low carbon economists，of low carbon transportation experts large scale together.Young people study in China then in Germany. And the German study in our universities and then here to seek that these two countries are moving into a different direction to organize a tipping point in the global transformation process.So international cooperation needs and can be improved.

I am coming to my last slide.When we have these different arenas in mind.Arenas of change towards a low carbon economy，we do have 3 important mechanisms which drive the whole process towards low carbon. And I would like to mention at the end of the lecture these big，important mechanisms.The first important mechanism is about co-evolution.Co-evolution means that this is not thing that you can governance.This is not something which you can steal.When you do have low carbon dynamics in policy arenas in terms of norms.In the arena of innovation，these different arenas are interacting and mutually reinforcing themselves.So if you get big innovations in technological arena，it is not easy to make policy reforms.Its norms and values are shifting.Policy reforms are easier.The number of actor is growing.So mutually reinforcing dynamics because we do have certain low carbon trends in many of these arenas.This is about co-evolution.The second mechanism is about transformational policies.Transformational policies are policies which do not only aim at organizing any efficiency gain，green efficiency gain.It’s about organizing transformational shifts which help us to climb this curve up.This is what the China Council for International Cooperation on Environment and Development which has its annual meeting during the next 3 days and I would participate there.This is what we are focusing on.What are transformational policies about？Not only energy efficiency oriented policies，but transformational policies. And we do have it here in our report also recorded the transformational policies we considered.

The last mechanism to make this transformation possible，is based on our reflection social contract on sustainability.We borrow this term of social contract from important European thinkers like Rousseau，Kant，and Hume.In their time，about 250 years ago more or less，they reflected on the transformation towards an industrial society，and towards the era of enlightenment of human rights，personal rights，citizen rights. And they argues in their work that this kind of shift in societies is only possible when a social contract in a society emerges between political actors，between society，between the private sector.So we borrowed from them，the idea that social contract is needed.Social contract obviously has something to do with the vision I spoke beforehand.The social contract for sustainability.We argued in our study that the abolishment of slavery for example，and the abolishment of child labor has been based on this kind of social contracts.This means that the transformation towards low carbon is not only something which we can drive by policies，instruments and incentives.It goes beyond that.For this transformations，we need base these transformational policies.We actually also need a social contract for sustainability.I think that in Chinese reflections on ecological civilization and how to balance the development and interests of human beings with its necessities of stabilizing the earth’s is something move to this direction.These are the 3 basic mechanisms which drive the processes towards low carbon transformation.

So ladies and gentlemen，thank you very much for your patience.It has been a long lecture，90 minutes. And I hope that you have found some of the ideas interesting enough to discuss about.Thank you！

Pan：Thank you very much，Dirk.It is very informative.Well，Professor Messner has given us a highly valuable lecture with regards to the global transformation towards a low carbon economy with planetary boundary.Everybody understands that we have technologies but so far it is beyond our imagination that we could be able to enlarge the boundary of our planet earth. And we have the technologies to improve our welfare but we are cornered by these planetary boundaries.In the meantime，professor Messner has emphasized that we do have the drivers to co-evolve the path toward a low carbon economy. And in the end，we have to go 0 carbon economy.I think it is absolutely the truth as Professor suggested.Before the industrial revolution，there was 0 carbon emission at all.All the energy was from natural resources and renewable. And probably 100 years later，when all the fossil fuels will be replaced，we would have low carbon emissions at last.So this is actually a must and professor has suggested that we have the opportunities and we have the challenges. And the country like Germany and China are making efforts and we have made enormous progress.In recent years，at the group level，there is a lack of international cooperation spirit.But this does not matter as soon as we move forward，we will have the solutions.

Now I think after 90 minutes，this very short lecture in terms of the information and the knowledge that you know that it contains. And I believe that we enjoyed a lot，and we learnt a lot.But still we would like to learn more and we would like to have some，you know，questions to discuss with the professor.So it is open in case anybody would have any questions or any observations or any comments.I believe that professor would be happy to discuss with you. And in case you have some，you know，difficulties in using the English language，of course，it is understandable since you know English is not our mother tongue. And we can use Chinese and I can help you to pass the message on to professor for the discussion.So don’t worry.If you can use English，that is perfect.If you use Chinese，there will be no problem as well.So the floor is open.Anybody if you have any question.Yes，please.

Student：First，thank you very much professor.Thank you very much for your presentation.I have a question.You mentioned that the carbon budget for the future greenhouse for the earth is 750 Gtons. And I have done some work for the carbon budget proposal under the advice of professor Pan. And during my calculation that this figure is too tight for reality we think.You know some natural scientists calculate this may be 1000 Gtons or higher，1400 Gtons. And you know without fundamental technology or policy in the next one or two decades，I think 750 Gton is impossible.So what is your opinion about this and what is your opinion about the carbon budget proposal for the future low carbon transformation？This is my question.Thank you.

Dirk Messner：First of all thank you very much for your question.I know that professor Pan and his team that you are also working on this budget idea. And we both actually represented our two concepts in Copenhagen two or three years ago already for international audience or for the international discussions.Our point this time was that to make the climate negotiations feasible and to push the climate negotiation progress forward.We need to translate our 2 degree Cels target into something which is more tangible.The end of the day，the tangible stuff is about the greenhouse gas emissions.We need to reduce the greenhouse gas emission and we need to know how big the budget actually is. And this is what our efforts being about.

And the question how to share the budget.This is a justice question.The justice question is very important.So now regarding the how many Gtons are available，the data from the nature scientists which we are calculating with and demonstrating that 750 Gtons are compatible with 2 degree target for the next four decades with the probability to reach the 2 degree target by 67%.If you reduce the probability to 50%，we can do that of course，it is a higher risk game.If you do that，we are ending up with around 1200 Gtons.It still is a challenge to make transformation.It is easier but you do have a higher risk.Higher risk means afterward warming 3 degree Cels.Our investments here inChina and globally will have higher risk of course.So we need to balance that.It’s about risk.It is about probabilities.It is about how fast we think that we can make the transformation.What is real anyway is for the second half of the century，the greenhouse gas budget will be very very small. And in your calculation，in our calculations，we talk about 200 or 300 Gtons for the second half of the century.So it needs to bring our emissions down during next 4-5decades on a very radical path.Our reflections are demonstrating that technically. And base on what we know now，we can do that. And froma financial perspective，it is possible. And I would add that countries which move forward now is pioneers of this process，do also accumulate economic advantagesin this process.

Pan：OK Thank you.I think that this is on the safe side.A tighter budget would ensure the 2 degree target and if we do not have a tighter budget，that would mean that we run a very high risk.So the second question.

Student：Thank you for the lecture.I wonder what is your perspective on the growth in your great transformation because some say that green growth is an illusion. And we need a justice de-growth in over developed countries and set the chance for the developing world.So I wonder.It may be a path dependence but it seems that to maintaining growth is to ensure everything else.So I wonder what is your perspective in this growth and dynamics in your great transformation？

Dirk Messner：Thank you very much for this question and it’s a very important thing. And a very difficult one to answer.Two weeks ago，we had a conference in Germany with Dennis Meadows.I do not know whether you know his name.Dennis Meadows was the author of The Limits to Growth.He is a 70 years old gentleman and 40 years ago，in 1972 he wrote his seminar work on the Limits to Growth. He was actually the first scientist who really focused on this kind of question，who said that imaging a world with a growing population becoming richer can be growth forever. And his answer is I think it is not possible.My answer is a bit more differente.I would argue that we still do have 2 billion people worldwide living with less than 2 dollars a day.So growth for them，wealth creation is a must.In the society，we do have a per capita income for a year around 1500 to 3，4000 dollars only organized by regional distribution that we do not get sufficient situation for people.So growth in poor countries is still absolutely necessary.But what we need to do is we need to control this growth from resource use and from the emission of carbon.This is the challenge which we are confronted with.We reflect on how this is possible.I will argue that in our industrial societies，the situation is different.In our societies，we need much less growthto have a level of development which is appropriate for human beings.You might know the income per capita in Germany is around 35000 euro per capita per year.People are not becoming wealthier and not becoming more lucky gaining 2 or 3000 dollars a month.So in countries in a high level of per capita，the growth issue is different from situations in poor countries.But the important challenge is the low carbon.We do have many sectors where do not consume materials. And this is where we meet to share our growth patterns.

Pan：This is also a matter of measurement.If we use GDP or the monetary measurement，then you know here income is actually an indicator.But this does not mean that more money would mean more happiness，and would mean a higher level of welfare.Take one example，if the life style is not very healthy，you eat too much，you drink too much and do not do that you know physical excises and then you have to eat a lot of medicine. And you eat a lot of medicine that generates a big mount of GDP.In the end，this is waste of resources.So life style is very important because what we need is the quality of living not the absolute physical wealth.We can have numerous wealth like renounce everywhere but in the end you do not enjoy your life，you do not have a very healthy and very quality style of living.So that is more important happiness because you know the welfare is not indicated by the amount of money you earned and the amount of wealth you would have.So who is the next？Yes，Please.

Student：Thank you for your wonderful presentation.My question is the clean development mechanism adds a wonderful way to solve the carbon trade between developing and developed countries.But there are some different voices on this.My question is how you comment on this CDM system？Thank you.

Dirk Messner：From my perspective，the mechanism is important because the major idea is that carbon companies from the US，from Germany invest low carbon technologies in developing countries reducing the emissions.We can translate this into the CDM mechanism and translate into the transfer of technologies and financial resources.If you look at the volume investments which are based on CDM mechanism，the volume is very small compared with upfront investments.So the CDM is important but it is not the driver of this kind of global transformation.Private investments，and big investments from big development banks are much more important.CDM is a small element in the big story.

Pan：I think you are certainly right.You know CDM is a mechanism to reduce the cost of emission reduction in the developed countries and help the developing countries for low carbon development.So this does have some impacts very positive but in the longer round，the amount of resources you know can be limited.So that is why we need to scale up level of financial investment.That is why professor suggested that the private sector involvement.Of course the CDM is involved by the private sector but the signal is very important that you know the CDM program promotes the market development in China，etc.in the past several years，the renewable energy installations rocketed.So the market signal is very important that CDM has it impacts.So who is next？

Student：Thank you very much for your excellent performance.Nowadays the low carbon economy is very hot today.I have a question what is your opinion of the China low carbon industry and which factor will play the most important role in the next decade？Can you tell us briefly？Thank you.

Pan：This is a very big question.

Dirk Messner：That is a very big question.We will try to answer in on the annual conference.I will focus on three very important dynamics which I would give priority to you.First is that China is one of the countries，I mean the country where the urbanization trends with combined the new middle class.This is the strongest worldwide.So in China，it is so important whether this country is making progress toward the creation of building the low carbon cities. And China is pioneer in this sector.So this is one of the very important arenas.Urbanizations，low carbon cities，low carbon urbanization.The second big area is the energy field because as Professor Pan told us at the very beginning energy consumption in China is still growing recently.So making and transforming the energy toward a low carbon in China is absolutely relevant.China is doing the biggest，in terms of volume，the biggest in low carbon energy arena.Germany is the second biggest investor in this field.So energy is absolutely important.The current figures are showing that China is make huge progress in energy efficiency gains but less progress in carbon efficiency gains.Its energy is still based by large proportion on fossil fuels.So moving towards to renewable energy is very very important.My last point is that the Chinese investment ratio is very high，40% from your GDP moves toward investment.Our investment ratio in Germany is around 23%.This implies that the dynamic with which you can re-structure your economic design much faster than most countries in the world.You can make this kind of transformation faster.So the question is whether the investments package over all moves step by step toward low carbon.This is the third important element I would have to say.

Pan：Low carbon transformation is certainly not cost free.But on the other hand we have to change our mentality.It is not，in the end an opportunity.These investments will bring energy security，would bring job positions，and would create a lot of job positions. And this will become the real driver for a growth of economy and also for income of the employees.In the interest of time，we may have a final one or two questions.

Student：Thank you Professor.In your lecture，you mention the international consensus of 2 degree Cels.So I wonder that would you please tell us some possible consequences if the earth system reaches the tipping point of 2 degree Cels？You know that there are positive consequences as well as negative consequences.So would please tell us some details for the possible consequences？Thank you.

Pan：OK.There is one more.We can take one more if there is any.So that is the last question.

Dirk Messner：Thank you very much for all your questions.I would argue in the following way.I would argue that actually we do have the chance to decide between three different types of great transformations.We are moving toward great transformation anyway.I have already talked about one great transformation toward low carbon.Low carbon is trying to avoid these risks of changing irrespectively.There is a second dynamic toward global transformation if you want a 3 or 4 degree.But most natural scientists are demonstrating to us that the risks which are related to 3 or 4 degree world are high in terms of access to water，in terms of access to soil，in terms of risk to weather and even bigger tipping points.Because imaginable the monsoon might collapse by the end of the century.We do not know what coming next.We cannot imagine a world where monsoon is not working.So the risks are very very high.This is the second possibility.We move toward global warming and we need to adopt to changes of the earth system.This is a big shift and this has to do with the great transformation also.There is a third，option which has been discussed currently.I have been talking about these issues in the US during the last month.I gave similar lectures in different universities，in Washington DC to the think tanks which are around there. And one of the biggest discussions there is the third.It is about geo-engineering.Gene engineering is about if the world is becoming warmer，what tries to invent to cool it down artificially.The cooling down artificial.Costs，unknown，risks，unknown. And people argue that this transformation might be too difficult，too challenging and then they go for geo-engineering.I will try to avoid the geo- engineering path because still it is possible to make the transformation towards low carbon.We know the design.We know the technologies. We know the policies.Why should we go to geo- engineering which implies the re-configuration of the earth system artificially on a global scale？I would like to avoid this.I mean we do have many problems to get a global climate regime in place.It is so difficult to gather 190 countries to get a climate regime.If we go to global geo-engineering，there are many issues which have to be discussed globally.If we put chemicals into the ocean for example，to improve the capacity of the ocean to observe greenhouse gases，who is being allowed to do so？And how much chemicals we should put into the oceans？Or we are going to put chemicals into the atmosphere to bring coolness into the atmosphere，who decide who can do that？And how much of this is possible and responsible？So we would need for a geo-engineering international rules also.If we do not have it，it will result international conflict obviously.So the geo-engineering path，from my perspective is what we should to avoid.I would argue for this idea，the great transformation. And the risks to our second transformation，a warmer world，are very very high.When you look at the tipping points，those are not small accidents in the earth system.These are big accidents to global earth system. And we do not know how to fix that.We do not know what the earth system will look like afterwards.Talking about the Amazon，with different institutes worldwide，we did studies on the Amazon. And the result demonstrated that with 3.5 to 4 degrees increased the possibility of collapse of the Amazon forest is high.What we cannot do，what we cannot model is to show how the water system and the soil system for Latin America as a whole will look like afterwards.We might run into serious food trouble in the whole region.So I would like to avoid the other paths.We all know the sustainability transformation. And let us go for that.

Pan：Great.Human being are very creative and innovative and sometimes，this creativity might go to the wrong end.Nuclear must be one example.Of course it does bring us some benefits but in the end，we are not sure what the final result would be.So this is one. And professor mentioned geo-engineering.Quite few scientists advocate this approach and that means we interfere with the natural system，and we artificially reverse the trend of nature circulation. And he gave one example.That is，put chemicals into the ocean that carbon dioxide can be absorbed by the ocean. And also some scientists suggest that we may send planes to atmosphere to spray something called aerosols to reduce solar radiation reaching the earth.The cost will not be that huge but the dangers，the risks are really unknown. And there is one thing that can be very clear that we need to minimize the human intervention with the natural system. And this is also a sort of mentality，a sort of cultural，or civilizational view shift because in the Party’s document it also as Professor mentioned the ecological civilization.This is in contrast to the industrial civilization.You know under the industrial civilization，the value that is very simple.Human beings are very powerful.We can conquer the nature. And you know the value is very simple.That is profit maximization. And then under ecological civilization，this is something different.The ethic value is something very different.We respect for nature.We work together with the nature.We must be in harmony with nature. And the value is not for profit maximization.Instead，for the quality of living.What we pursue is quality of living instead of paper money.For everybody，life is limited.There is nothing called long long life.If we look at life expectancy，the Japanese is the highest in the world.Some is 83 years old. And then very few people could live longer than one hundred years.So the quality of living is the most important for everybody，for our next generations.So we need to have paradigm shift，or shift of civilizational views.Otherwise，the technologies will not help us in qualities of living.Technologies are very important.But more importantly is that we have civilizational views.

Well，I think I enjoyed and learnt a lot from professor’s very stimulating，very informative lecture. And also the interactive discussions seem to be very productive as well. And I would like to inform you that Professor’s institute is very well-known think tank in the world. And he does invite applications for post doctorate researchers in his institute and also he works with universities. And in these universities，opportunities for exchanges，for some joint researches as well.It is a small world.You know geographically China and Germany are somewhere depart.But under modern transport for us and also internet，the world is not that huge.We can work together.So I encourage you to get in touch with professor.I do believe the Graduate School would have the information for further communication.I would invite the audience，everybody，to join me to thank professor for his excellent lecture.Thanks a lot.

Thank you for your participation.

（语音整理：胡纯、齐雨婷、梁洪基 初稿整理：李阳）