汉娜·里奇会让你对气候变化持乐观态度 | 盖茨播客

当我开始对我们面临的气候挑战感到不知所措时，我会求助于Our World in Data的研究员汉娜·里奇。她以数据为导向的方法是对环境末日论的重要解药，并为人类解决重大问题的能力提供了急需的乐观态度。最近，我与汉娜坐下来讨论了她的新书《Not the End of the World》，也谈到了为什么我们很难理解人类进步，我们会问一个时间旅行者关于未来的什么问题等等。

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汉娜·里奇：我的书的核心信息是：空气污染、气候、食物、生物多样性，这些都是难以解决的问题，但我认为我们有能力解决它们。所以，说解决这些问题为时已晚是不对的。

比尔·盖茨：我有很多好老师，我从他们身上学到了很多。我的小学有一位图书管理员。我有一个很棒的网球教练。你知道，要想对一件事情不困惑，最好的办法就是找到真正深刻理解它的人。我称之为“解惑”。

欢迎来到“为自己解惑”，我是比尔·盖茨。

比尔·盖茨：我的嘉宾是汉娜·里奇博士，她是牛津大学的数据科学家和研究员，也是Our World in Data的研究负责人。她即将出版一本非常棒的新书，名为《Not the End of the World》。

比尔·盖茨：欢迎，汉娜。

汉娜·里奇：很高兴能来到这。

比尔·盖茨：汉娜，当你做TED演讲时，那本书已经写完了吗，还是在写作过程中？

汉娜·里奇：那时候书已经写完了。

比尔·盖茨：哦，好的。

汉娜·里奇：所以TED演讲就像是书内容的一个压缩版。

比尔·盖茨：他们给了你15分钟的演讲时间吗？

汉娜·里奇：感觉像是很久很久以前的事了，一切都过得飞快。就好像，我实际上不记得我在台上说了什么，但我回看了演讲视频，我说了我想说的大部分内容。

比尔·盖茨：稍微介绍一下你是如何开始写这本书的。

汉娜·里奇：是的，谢谢，我的学历背景是环境科学。我读了本科、硕士和博士，都是环境科学专业。我想，在我完成学业的时候，尽管我学习环境科学很长很长时间了，但我仍在某种程度上感到相当无助，因为我们所面临的问题巨大且繁多。而且在当时，我觉得我们对这些问题没有取得任何进展。

所以，尽管我做了所有这些工作，我在如何应对这些问题上感到有点无助。然后我开始在Our World in Data工作，我的工作用的是一种更加数据驱动的方法，与其关注一直涌向我们的新闻头条，不如退后一步，查看数据以理解这些问题以及我们如何解决它们。

所以在过去的六七年里，我在Our World in Data所做的就是研究这些环境问题，以及健康、贫困等我们面临的其他问题，并试图理解我们在这些问题上的状况以及我们如何应对它们。我在书中所做的，就是选取七个不同的环境问题，比如空气污染、气候、食物、生物多样性，并试图描绘出我们从哪里来，我们今天在哪里，以及这告诉我们接下来需要做什么。

比尔·盖茨：有一大群人，我猜你可以称他们为“末日论者”，他们对于“我们无能为力”、“该不该要孩子”这类事情感到绝望。你认为这种看待环境问题的方式怎么会变得如此普遍？

汉娜·里奇：是的，我认为这是一个日益严重的问题，我得说，大约十年前，我可能也是一样的看法，我当时在研究这些环境趋势，它们似乎都在变得越来越糟。但在当时，我完全不了解人类福祉趋势是如何变化的，比如贫困、健康、教育方面发生了什么变化。

我只是简单地推断说：“好吧，我看到所有这些新闻头条都在说，看看有多少人在挨饿，有多少孩子在死去”，就像所有这些趋势一样，我只是假设所有这些同时都在恶化。

对我来说，我们似乎没有能力解决任何问题。后来，我发现了汉斯·罗斯林（Hans Rosling）的工作，这对我来说是一个重大的转折点，他真正地将世界在这些人类福祉指标上的变化搬上了台面。但我认为，现在之所以有这么多人感到末日即将降临，原因之一是我们没有认识到人类在过去几个世纪中所取得的巨大进步。

比尔·盖茨：你的书的一个很好的地方是，尽管气候问题可能是最受关注的，但你还谈到了我们面临的其他环境挑战。请说说其中的几个。

汉娜·里奇：是的，第一章是关于空气污染的，我认为这是一个被低估的问题。如果你看看空气污染导致的过早死亡人数，实际上比现在的气候变化要高得多。这种情况将来可能会改变，但对我来说，空气污染是我们面临的最大的健康挑战之一。

世界卫生组织估计，每年大约有700万人过早死亡。一个是室外空气污染，这是我们看到的，比如汽车和发电站等的排放，这是一个大问题，但还有一个被极度低估的问题，那就是室内空气污染，主要是处于能源贫困中的人们，他们唯一的燃料是木材、木炭或农作物废弃物。他们基本上用这些在家里取暖和做饭。由此产生的空气污染对健康的损害真的很大。在空气污染方面，我们已经取得了很多成就。一个是臭氧层，这是我从历史书上才知道的，毕竟我错过了臭氧层的大部分时期，但在当时，那是一个巨大的问题。各国齐心协力，将造成臭氧消耗的气体的排放量减少了99%以上。

酸雨是另一个问题，特别是在欧洲和北美，酸雨曾是一个大问题，我们基本上已经解决了这个问题，不仅是在富裕国家，你现在也能在中等收入国家中看到这点。比如中国，当地的空气污染已经明显减轻。在富裕国家，比如我所在的伦敦或爱丁堡，当地空气污染也大幅减小，这挽救了许多人的生命。所以我们已经解决了一系列问题，这在某种程度上反驳了我们无法解决环境问题的论述。

比尔·盖茨：是的，解决空气污染的一大好处是从煤炭转向太阳能或风能。你可以清除煤炭产生的本地污染，因此，在这里气候问题与本地污染问题有一些交集，对于关心本地污染和温室气体的人来说，煤炭都是主要的敌人。

汉娜·里奇：是的，在空气污染方面，你往往会看到所谓的环境库兹涅茨曲线，它并不适用于每一个环境问题，但你肯定会在空气污染方面看到它，它几乎像一个倒置的U型，空气污染程度往往会在收入非常低的国家较低，但随着国家工业化的发展，它会上升，并在中等收入国家达到顶峰，然后富裕国家——一旦国家变得富裕，它就开始下降，所以它就像一个倒置的U型。

这本身就是有希望的，它意味着，一旦每个人都富裕起来，那么问题就解决了，但我认为我们面临的挑战，以及我们需要推动的是如何加速这一趋势，让它变得更快。因为如果我们继续等待，在这条曲线下死亡的人数将会非常非常多。因此，问题在于，印度或其他中低收入国家能否比英国或美国更快地经历完这一趋势，因为这样做将挽救大量生命。

比尔·盖茨：我惊奇地发现，在海洋塑料垃圾中，来自北美的部分其实很少，所以这是另一个类似问题，可能不用花多少钱就能大幅减少塑料垃圾。

汉娜·里奇：对我来说，我认为塑料污染是一个关键领域，但我觉得关注点有些失衡。我认为我们一想到塑料，就立刻想到停止使用它们。所有的条约都是基于尽可能减少塑料使用。但实际上，塑料污染问题，比如塑料进入海洋，不是关于使用塑料，而是关于如何管理它。

当涉及到海洋时，我们产生的塑料垃圾中大约有0.5%最终进入了海洋，因此，解决这0.5%的问题要比解决产业链顶端100%的问题有效得多。当你查看全球塑料使用地图时，是的，富裕国家的人均塑料使用量和塑料垃圾量要高得多，我们使用的塑料也更多，但不同的是，我们在封闭管理的情况下将其送往垃圾填埋场，或回收利用，或焚烧处理，而大部分泄漏到海洋中的塑料更多地是在中等收入国家，这些国家的经济增长非常快，工业化进程也非常快，但废物管理却没有跟上。因此，这些国家使用大量塑料，但却没有其他废物管理基础设施来收集和保存这些塑料。因此，是的，这是一个非常容易解决的问题。如果在废物管理上投入一点资金，就能真正解决这个问题。

比尔·盖茨：当你查看环境数据时，我们真的减少温室气体排放了吗？有没有我们温室气体排放量下降的例子？

汉娜·里奇：是的，所以在温室气体排放方面，我想，纵观全世界，情况非常复杂，但在全球层面上，我们确实看到了二十世纪90年代和二十一世纪初的快速上升。在过去的十年左右，我们看到了变化速率趋于平稳——排放量仍在一点点增加，但增加得非常非常慢。

特别是一些富裕国家，在过去几十年里已经成功地大幅减少了排放量。例如在英国，排放量大约减少了一半，其中一些是由于外包生产，但并不全是。所以，即使我们考虑到这一点，排放量也在下降。中等收入国家，同样，情况有点复杂，我们的一些科学家看到了排放量的下降，而低收入国家的人们越来越容易获得能源，你会认为这些国家的排放量会上升，而事实也是如此。

比尔·盖茨：是的，英国的数据让我很吃惊，因为，当然，工业时代煤炭的整个能源密集化，都是从英国开始的，但他们却是在这方面取得最大进步的国家之一？

汉娜·里奇：是的，英国的碳排放问题基本上与煤炭有关，比如我们的大部分电力过去都来自煤炭，所以当我出生时，它占了一半到三分之二，但现在我们基本上不使用煤炭了，所以我们完全从电力指标中剔除了煤炭，这对碳排放产生了巨大的影响。

比尔·盖茨：是的，我们面临的挑战是，如何让人们了解每个行业，以及在创新方面有哪些进展，这些创新可能会让该行业的碳排放量降下来，而不会让成本变得太高。人们知道电动汽车，也知道风能和太阳能，但就排放和我们可能做到的事情而言，人们可能对其他大部分事情都不太了解。

汉娜·里奇：是的。如果把全世界的排放量打散排序，有发电，有交通。现在，这两个加起来相当大，但它们并不是全部。

我觉得对于这些行业，我们确实有经济解决方案。在过去的十多年里，我们看到太阳能、风能、电池和电动汽车的成本急剧下降，我认为对于这些行业来说，现在要做的就是非常非常迅速地有效利用这些技术，对吗？

在过去的十年中，我们一直在降低成本，在尽可能多、尽可能快地建设。但在其它领域，我们仍然需要创新。我们需要水泥，需要钢铁。对我来说，一个经常被忽视的重要领域是食品行业。我认为食品和农业脱碳将非常非常困难。因此，我们需要采取双管齐下的方法，一方面我们需要快速发展现有的技术，另一方面我们也需要为其它领域的创新投入资金和研究，这样到2040年或2050年，我们也能为这些领域提供负担得起的解决方案。

我确实认为富裕国家有几项责任。其一，它们需要降低国内排放，但我认为它们的另一个作用是，它们需要降低中低收入国家使用这些技术的成本。中低收入国家无法面对这样两难的选择：是让人们摆脱能源贫困，还是保持低碳排放？但富裕国家可以发挥的作用是降低这些技术的成本，这样就不存在权衡得失了，对吗？最便宜的技术也是低碳的。这也是富裕国家除了气候融资机制之外，另一种做出贡献的方式。

比尔·盖茨：是的，我完全同意这一点。实际上，我所说的成本就是所谓的绿色溢价。（富裕国家的）这种义务不仅是要实现零排放，还要降低这些成本——你知道，你刚刚提到的那种权衡，比如在印度，需要允许他们说，“好的，我们要建造基本的住房”，同时不会大幅增加他们的排放量。基本上所有环境问题的解决方案都是，随着你变得越来越富裕，你的人口增长趋于下降，然后你监测森林火灾的能力，或者建造在自然灾害时能让死亡人数减少的建筑的能力会增强。你有一张令人难以置信的图表，显示特别是在富裕国家，自然灾害造成的死亡人数大幅下降，这实际上与减少龙卷风、洪水、地震无关，而是与拥有一些预警系统和抵御这些负面影响的能力有关。

汉娜·里奇：灾难死亡人数的下降趋势着实让我感到惊讶。我曾认为要成为一个了解情况的公民，我必须一直在看新闻，所以这就是我了解世界的方式。但当你看新闻时，你看到的全是灾难、灾难、灾难。如果你让我描绘一下世界灾难死亡人数的趋势，我会说这是有史以来的最高水平。实际上，当你回过头来看这些数据时，情况恰恰相反，由于抗灾能力的增强，我们的灾害死亡人数出现了非常非常显著的下降。

比尔·盖茨：如果你展望2100年，许多模型看起来相当乐观，因为在那个时间框架内，经济会有巨大增长。

汉娜·里奇：是的，我的看法是，我们确实有适应的能力，我们有能力使我们的建筑、我们的基础设施更具韧性。我认为关键在于，我们需要确保这在全球范围内具有包容性。最贫穷的人将会受到最严重的打击，因为他们没有能力来重建家园。

比尔·盖茨：是的，所以明确一点，你的意思是，尽管成为一个末日论者并不是看待这个问题的正确方式，但你在书中谈到的所有不同领域的紧迫感仍然非常高，你希望看到我们能够更快地取得进展。

汉娜·里奇：是的，整本书都在说这些都是重大而紧迫的问题，我们需要真正行动起来。我想反驳的是，我们对此无能为力。对我来说，我们似乎很快就从这种极端边缘化的否定论转变了，尽管否定的声音响亮且巨大，但似乎又突然直接转向了“为时已晚”，我们无能为力了。我书中的关键信息是，这些问题很难解决，但我认为我们有能力解决它们，所以现在解决这个问题并非为时已晚。

比尔·盖茨：嗯，我肯定会把这本书送给很多很多人。就像在全球健康领域，我们必须讲述取得巨大进展的故事，因为从中可以吸取经验教训，让人们保持参与，即使大流行病是一个很大的挫折。在包括全球健康在内的任何领域，都很容易让人觉得，哦，我们并没有取得多大进展。因此，书中有一些积极的数据点，并且有一定的全面性，我认为这非常好。我期待它将引发的所有讨论。

汉娜·里奇：如果每个人都喜欢这本书并且喜欢书中的一切，那这本书就不会有影响力。它旨在引发讨论。如果我们能围绕我试图在书中呈现的数据展开讨论，那么我想我就已经有所成就了。这本书一个很酷的地方在于它不只是说，“嘿，伙计们，一切都很好，我们可以坐等”。这本书就像一个行动的号召，它试图展示我们的现状，号召在我们解决这些问题的基础上再接再厉，同时也试图展示我们下一步需要做什么。嗯，我希望它能激发更多的行动，而不是减缓行动的步伐。

比尔·盖茨：所以，我这里有一台唱片机，就像我对待所有嘉宾那样，我问你能不能带来一张对你有意义的唱片。所以，看起来你带来了一张？告诉我它的故事。

汉娜·里奇：是的，我应该先声明这不是我的，如果你年龄在30岁以下且有一张黑胶唱片，你就很酷，而我没有达到酷的标准，所以我不得不从我爸爸的收藏中抢。我这里有一张叫做《生命何其伟大》（Life is Grand）的唱片，是由一个叫做贝多芬露营车（Camper Van Beethoven）的乐队演奏的。你想让我给你播放吗？

比尔·盖茨：当然。

汉娜·里奇：我认为我选择它的部分原因是，我认为，如果你问我，人类历史上的任何一个时刻，比如我想在什么时候出生，我仍然会选择今天。尽管我们面临着环境危机，我认为这是作为一个人活着的最好时代。我想让人们对我们可以创造的未来充满希望。我知道这会遭到环保主义者的反对，但没关系。我想引起人们的讨论。这就是我选择它的原因。

我小的时候，我爸爸会放黑胶唱片。我带了一张我爸爸的唱片，这很有意义，因为我觉得他对我的影响很大，不一定是我的想法，而是我的思维方式。我记得小时候，他总是扮演魔鬼代言人的角色。所以，不管我持有什么观点，他都会用不同的观点来反驳，即使他同意我的观点。当时，作为一个孩子，我发现这真的很烦人和令人挫败。但我认为他真的教会了我如何以不同的方式思考事物，我认为这是我今天思考方式的一部分。比如，我们面临的问题是复杂的，它们不是单一维度的。你需要从不同的角度和通过不同的学科来解决它们。我认为他教会我如何思考的方式是十分重要的。

比尔·盖茨：太棒了。

汉娜·里奇：所以当我深入研究一个新话题时，我总是对它充满好奇，并以开放的心态来看待它。我认为，在证据发生变化时，需要有改变想法的意愿，我的意思是，这就是科学的真谛。最近有什么事情让你改变了想法吗？

比尔·盖茨：我在技术领域花了很多时间，我必须说，我非常惊讶于人工智能是如何从基本上根本不会读写，到以一种非常灵活的方式进行读写，虽然还很不完美，但这确实让我大吃一惊。我曾挑战人们通过一个测试，并认为他们可能永远不会，或者至少需要几年时间，但在几个月内，他们就能做到了。所以现在，我在思考，哇，我们如何在教育、健康和各种环境挑战中使用这个技术？所以，我错估了人工智能的力量，我已经改变了看法。

汉娜·里奇：你认为人工智能会在气候行动中发挥作用吗？

比尔·盖茨：绝对会，因为我们有能力为复杂现象建模，人工智能在这方面帮了大忙。例如，研究奶牛的基因，然后说，嘿，有些奶牛排放大量甲烷，有些排放得非常少，有些奶牛在炎热的天气里生存得很好，有些则不行。再加上我们编辑基因的能力，对于最显著的排放源之一，我曾不确定应对的前路是什么，现在我们可以看到，要么让奶牛变得更好，要么用各种技术在没有奶牛的情况下制造肉类。

因此，人工智能的强大之处在于，它可以查看这些基因并发现其中的规律。甚至天气建模现在也在应用人工智能，包括长期的，即那些气候模型，比如说，告诉非洲的农民，基于天气，他们应该现在就开始种植，还是未来会变得太干旱。他们过去总是在第一场雨后播种。但是如果你知道那是异常的，那么你就不应该播种。因此，人工智能确实开始帮助我们解决非常实际的问题。对你来说，新数据在哪个领域改变了你对事物的看法？

汉娜·里奇：我对许多技术变革的一般框架是，如果你能创造出与原有技术一样好，而且比原有技术更便宜的替代技术，那么人们就会采用它。我认为能源也是如此。我认为，人们并不关心插头里到底装的是什么，他们只想要可靠的电力。

我认为，现在我对这一框架持怀疑态度的一个领域是食品。我现在非常支持肉类替代品。我喜欢不可能汉堡（Impossible Burger）、别样肉客汉堡（Beyond Meat burger）。我是素食主义者，所以我一直吃这些东西。我在脑海中有这样一个框架：如果它们变得足够便宜并且味道好，人们就会做出转换。我现在变得更加怀疑这种转换是否会那么容易。我认为许多人将会有一种固有的抵抗感，那不是肉，所以我不会做出转变。所以对我来说，我更倾向于认为如果我们要看到这种大规模的饮食习惯变化，你基本上需要生成肉，例如实验室培养的肉，这不仅仅是植物基替代品，而是真正的东西，只是不用牛或鸡。

比尔·盖茨：是的，你有三种方法来解决这个问题，使牛变得更好，但即便如此，你还是会遇到道德伦理问题，或者有人使用植物材料，但他们在口味或成本方面并不成功。我知道他们有新一代产品即将推出，所以我希望它会有所改善。但正如你所说，以细胞为基础的方法，在口味上不会有问题。他们面临的挑战主要是成本。但现在有一些很棒的公司，包括一个叫做Prolific的公司，看起来我们可能会实现这一目标。有时候路径要长得多，我们低估了像“别样肉客”和“不可能食品”成为主流的难度，但他们在推出新版本产品了。所以我仍然抱有希望。在这个肉类替代品领域，有没有你觉得吸引人的产品？

汉娜·里奇：我吃素很多年了，去年我变成了严格素食者。我非常喜欢肉类替代品。我认为我最喜欢的是“不可能汉堡”（Impossible Burger）。我吃过它，那应该是2019年，当时我和我的团队在旧金山待了几个月。但在英国买不到。

比尔·盖茨：哦，真的吗？

汉娜·里奇：所以当我吃到“不可能汉堡”的时候，我觉得那真的让我找回了吃汉堡的感觉和味道。它唤醒了我认知中许多年没吃的，真正的牛肉汉堡的味道。很可惜，在英国还没有“不可能汉堡”。我认为我最喜欢的是“别样肉客”。我觉得味道真的很好，质地也很好。我敢肯定许多吃肉的人会不同意，认为这与他们的体验不太相符。但对我来说，它相当不错。你呢？

比尔·盖茨：我不得不说，香肠对他们来说是更容易做到让我真假难辨的一类食物，或者鸡肉三明治也一样。牛肉馅已经做得很接近了，特别是你还会在里面加盐和酱料。最难的可能是牛排，尽管有公司声称他们也能实现。几乎每一种类型的食物、奶酪，都有一些有趣的工作正在进行。如果你能让牛肉或猪肉以这种方式生产出来，很显然，这甚至有助于解决森林砍伐等问题，因为这些动物的喂养有一个完整的链条。所以，我一直关注农业，也一直在尝试这些东西，有一种（人造）酸奶我觉得非常棒。

汉娜·里奇：我认为我们在鱼肉上还差的相当远。我还没有尝试过真正符合鱼肉口味的肉类替代品。

比尔·盖茨：是的，对于鱼肉，有一种从海洋捕捞转向所谓的水产养殖的大趋势。这一开始是一件对环境非常不敏感的事情，但现在他们真正改善了废水处理和疾病控制。有趣的是，我们现在几乎有一半的鱼类来自水产养殖，至少在非洲，有更多这样做的好处。这不是鱼的替代品，只是另一种养鱼方式。

比尔·盖茨：如果你有机会问一个从2100年回来的时间旅行者发生了什么，你最想问他们的问题是什么？

汉娜·里奇：我认为我最想问的问题之一是，世界上有多少人每天的生活费不足20美元？我认为，展望未来，我希望看到的是世界上大多数人或每个人都过上舒适的生活。现在，我们可以通过极端贫困率来捕捉到这一点，极端贫困的人基本上就是每天只靠几美元生活。这些贫困线是非常低的，我想知道有多少人仅靠每天20-30美元生活，这是富裕国家的贫困线。现在，我们有一些中低收入国家正在设法达到这一收入水平。我认为这将是一项了不起的成就。

对我来说，这将意味着几件事。仅仅这个问题就会表明，我们在健康、农业、（消除）贫困方面取得了进步吗？因为我认为所有这些问题都是相互联系的。我认为在大多数人都超过贫困线的国家，你通常会有良好的健康状况，你可能也有非常高效的农业。

我认为这也能说明我们在解决环境问题方面做得如何。如果是这样的话，那么我的假设就会是：气候变化并没有造成极具破坏性的影响，即农业被毁，健康状况极差，人们陷入贫困。我想，如果我能问一个问题，我就会问这个。

比尔·盖茨：不，我认为这个问题很聪明，因为最终，一切都要通过人类福祉来衡量。最终目标不是减少塑料或者达到某个特定的温度。关键是人类是否蓬勃发展，这非常符合盖茨基金会工作的优先顺序。我不得不说，如果我遇到这个人，我会想问，你们是如何生成能源的，是通过聚变、裂变还是某种意想不到的方式，然后了解人工智能是如何帮助他们团结起来减少分化，或者他们是如何应对这一挑战的。但你说得对，成绩单不是最终策略，但生活质量是。

汉娜·里奇：是的。

比尔·盖茨：那么，当你不那么努力工作时，你做什么来放松呢？

汉娜·里奇：我真的很喜欢锻炼。我喜欢跑步和去健身房，我还做很多抱石，那种没有绳索的室内攀岩。我认为对我来说，锻炼真的很关键。我觉得通常我运动的时候还是有点像在工作。我觉得我在跑步的时候，经常会有很好的想法，比如我经常会在跑步的时候想好要写的文章。但我想，对我来说，这是一个产生想法的好工具。我觉得对我来说，运动是一件大事。你呢？

比尔·盖茨：对我来说，是网球和匹克球。我可能应该做更多的跑步或锻炼，我也确实做了一些，但网球很有趣。我有很多朋友，那是一项健康的活动，也是一个从工作中分散注意力的好方法。

比尔·盖茨：嗯，感谢你能来，我真的很享受我们的对话。

汉娜·里奇：不，非常感谢你邀请我，这是一次非常有趣的聊天。

比尔·盖茨：《为自己解惑》是盖茨笔记的一档节目。特别感谢我的今天的嘉宾，汉娜·里奇。

比尔·盖茨：我喜欢强迫自己写作，尽管这需要很大的自制力。

汉娜·里奇：对我来说，我是一个非常——我是说，我白天也有工作。所以对我来说，我是一个非常早起的作家。我早上四五点起床，那时候我的写作才最高效。

When I start to feel overwhelmed by the climate challenges we face, I turn to Hannah Ritchie, a researcher at Our World in Data. Her data-driven approach is an essential antidote to environmental doomsday-ism and provides some much-needed optimism about humanity’s ability to tackle big problems. I recently sat down with Hannah to talk about her terrific new book Not the End of the World, why it’s so hard to wrap our minds around human progress, what we would ask a time traveler about the future, and more.

HANNAH RITCHIE: The key message of my book is that air pollution, climate, food, biodiversity, these are hard problems to solve. But I think we are capable of solving them, and it’s just not the case that it’s too late to tackle this. 

[music] 

BILL GATES: I had great teachers that I’ve learned from. I had a librarian at my elementary school. I have a great tennis coach. And, you know, the best way to get unconfused about something is to find somebody who really deeply understands it. I call that, ‘getting unconfused’. 

[music] 

Welcome to Unconfuse Me, I’m Bill Gates. 

[music fades] 

BILL GATES: My guest is Dr. Hannah Ritchie, a Data Scientist and Researcher at the University of Oxford, also Head of Research at Our World in Data. She’s just coming out with a fantastic new book called Not the End of the World. Welcome, Hannah. 

HANNAH RITCHIE: It’s a pleasure to be here. 

BILL GATES: Hannah, when you did your TED talk, was the book written by then? 

HANNAH RITCHIE: The book was written by then, yes. 

BILL GATES: Oh, okay.  

HANNAH RITCHIE: The TED talk is a little bit of a squished down version of the book.  

BILL GATES: Yes, that went very well. Did they give you 15 minutes for that?  

HANNAH RITCHIE: It seems like a long, long time ago, and it went by in a complete blur. I actually don’t remember what I said when I was up there, but I watched it back and I said most of what I wanted to say. 

BILL GATES: Tell me a little bit about how you came to write the book. 

HANNAH RITCHIE: Yes, thanks. So my background is environmental science. I did a bachelor’s, a master’s, a Ph.D., all in environmental sciences. And I think by the end of my degree, despite having studied environment for a long, long time, I felt, to some extent, quite helpless. I felt like the number of problems we were facing were huge. The problems were massive. And, to me at the time, it seemed like we weren’t making any progress on these problems. So despite having done all of this work, I felt kind of helpless on how do we tackle these issues. And then I started working at Our World in Data. And my work led to a much more data-driven approach where rather than focusing on news headlines, which are coming at us all the time, it’s stepping back to look at the data to understand these problems and how we solve them. So what I’ve done at Our World in Data for the last six or seven years is to study these environmental problems amongst health, poverty, other problems that we face, and try to understand where we are on these problems and how we tackle them. So what I do in the book is I take seven different environmental problems, so air pollution, climate, food, biodiversity, and try to paint a picture of where we’ve come from, where we are today, and what that tells us about what we need to do next.  

BILL GATES: There’s a large group of people, I’d guess you could call them doomers, who are feeling a sense of despair about, “There’s nothing we can do, should we have kids?” that type of thing. How do you think that got to be such a common way of looking at the environmental issues? 

HANNAH RITCHIE: Yes, I think it’s a growing problem. And I should say that a decade ago I was probably in that very same position. I was studying all these environmental trends and they all just seemed to be getting worse and worse and worse. And I think what I was also doing at the time is that I had no understanding of how human wellbeing trends were changing, so what was happening to poverty, to health, to education. And what I did is I just simply extrapolated and said, "Well, I’m seeing all these news headlines saying look at the number of people in hunger, the number of kids dying," all of these trends, and I just assumed all of these were getting worse at the same time. So to me it seemed like we were incapable of solving any problems. And I think then a big turning point, for me, was discovering the work of Hans Rosling, who really brought to the front how the world has changed on these human wellbeing metrics. But I think one of the reasons why so many people feel a sense of doom now is that we fail to also recognize the amount of human progress that we’ve made over the last few centuries. 

BILL GATES: One great thing about your book is that, although climate is probably the problem that gets the most attention, you talk about other environmental challenges we face. Talk about a 

few of those. 

HANNAH RITCHIE: Yes, the first chapter is on air pollution, which I think, for me, is just an underrated problem. If you look at the number of premature deaths from air pollution, it’s actually much higher than climate change today. Now, that might change in the future, but, for me, air pollution is one of the biggest health challenges we face. The WHO estimates that it’s around 7 million premature deaths every year. You have outdoor air pollution, which is what we see as the emissions from cars and power stations, et cetera, which is a big problem. But there is also a vastly underrated problem, which is indoor air pollution, which is basically people, mostly in energy poverty, where the only fuels they have are wood or charcoal or crop waste. And they’re basically using this to heat and cook in their homes. And the amount of air pollution that you get from this is really, really damaging to health. Now, on air pollution we have achieved a lot there. One is the ozone layer, which I just learned about from history books, because I kind of missed the whole ozone layer period, but at the time, that was a massive problem. Countries came together and we reduced emissions of these ozone depleting gases by more than 99%. Acid rain is another one, especially in Europe and North America, acid rain was a massive problem and we’ve basically solved that. And now you’re starting to see it in middle-income countries. So China, for example, has seen really stark declines in local air pollution. But when you take rich countries, so London or Edinburgh where I’m from, you’ve seen really dramatic reductions in local air pollution, which has saved a lot of lives. So there are a range of problems that we have solved. Which I guess pushes back against this narrative that we’re incapable of solving environmental problems.  

BILL GATES: One nice thing about that is that going from coal to solar or wind, you can clean up local pollution from coal. And so there is a little intersection with climate there, where for the local pollution people and the greenhouse gas people, coal is the primary enemy. 

HANNAH RITCHIE: Yes, I mean, on air pollution, you tend to see what is called the

Environmental Kuznets Curve, which doesn’t apply to every environmental problem. But you definitely see it with air pollution where it’s almost like an upside down ‘u’. So air pollution tends to be lower at very, very low incomes, and as countries industrialize, it goes up and reaches a peak at middle-incomes. And then rich countries, once the countries get rich, they start to decline, and so it’s like an upside down ‘u’. Now that is in itself promising. That just means once everyone gets rich then the problem is solved. But I think the challenge we face, and what we need to push for, is how do we accelerate that trend much, much faster. Because if we wait, the number of deaths under that curve is really, really big. So the question is, can India or other middle- and low-income countries go through that trend much faster than the U.K. or the U.S. did, because doing so will save a lot of lives.

BILL GATES:  I was stunned that of the plastics in the ocean, the portion coming from, say North America, is actually pretty small. And so that’s another one where it might not be that expensive to see a big reduction.

HANNAH RITCHIE: For me, plastic pollution is one key area where I think the tension is kind of lopsided. I think we think of plastics, and we immediately think to stop using them. And all of the treaties are based on how we reduce plastic use as much as possible. But, actually, the problem of plastic pollution, like plastic going into the ocean, is not about using plastics, it’s about how it’s managed. And when it comes to the oceans, around 0.5% of our plastic waste ends up in the ocean. So it’s actually much more effective to tackle that 0.5% than to tackle the 100% way at the top of the chain. When you look at maps of plastic use across the world, yes, plastic use and plastic waste per person is much higher in richer countries. We use more of the stuff, but what’s different is we send it to landfills where it’s closed and managed, or we recycle it, or it’s incinerated. And most of the plastic that is leaking into the ocean is more in middle-income countries where they’ve seen very fast growth and very fast industrialization, but waste management has not managed to keep up. But they’re using lots of plastic, but there’s not the waste management infrastructure there to gather it and to keep it. So, yes, it is a very tractable problem. If you invest a little bit of money in waste management, you can actually put a massive dent in that problem.

BILL GATES: When you look at environmental numbers, have we actually reduced them anywhere? Are there examples where our greenhouse gas emissions have gone down? 

HANNAH RITCHIE: Yes, so on greenhouse gas emissions, I guess, across the world, it’s a very mixed picture. On a global level, we did see a very rapid rise in the 1990s and early 2000s. Over the last decade or so we’ve kind of seen a bit of a plateauing, emissions are still increasing a little bit, but they are going up very, very slowly. So rich countries in particular have managed to significantly reduce emissions over the last few decades. In the U.K., for example, emissions have approximately halved, and some of that is because of offshoring, but not all of it is because of offshoring. So even when we account for that, emissions are going down. Middle-income countries are a bit of a mixed picture where some are starting to see a decline. And then in lower-income countries, as people are gaining access to energy you would assume the emissions are going up, and they are.

BILL GATES: Yes, the U.K. number was quite striking to me because, of course, the whole energy intensification with Industrial Age coal starts in the U.K., and yet they’re one of the countries in that area that has made the most progress of all.

HANNAH RITCHIE: Yes, I mean, the story of carbon emissions in the U.K. is basically about coal, like most of our electricity used to come from coal. So when I was born, it was between onehalf and two-thirds, and now we are basically coal-free. So we’ve just cut coal completely out of the electricity metrics which just makes a massive difference to your carbon emissions.

BILL GATES: Yes, the challenge is getting people to understand each of the sectors and what’s in the pipeline in terms of innovation that might allow that sector to get its numbers down without having the cost be so gigantic. People know about electric cars, and they know about wind and solar, but most of the rest of it is probably pretty opaque to people in terms of emissions and what we might be able to do. 

HANNAH RITCHIE: Yes, if you split up the world’s emissions, there are the power sectors, so electricity, there’s transport. Now, those two combined are quite big, but they’re not everything. I think the way I see it is with these sectors we now actually do have economic solutions there. Over the last decade or so we’ve seen plummeting costs of solar, wind, batteries and electric cars, and I think for those sectors, it’s now about deploying these technologies very, very quickly. The last decade it was getting the cost down, and in this decade, it’s building as much as we can, and as fast as we can. But there are other sectors where we still do need innovation. We need cement, we need steel. A big one, for me, that is often overlooked, is the food sector. I think decarbonizing food and agriculture is going to be very, very difficult. So we have this two-end approach where we need to go fast on the stuff that we have now, but we also need to be putting money and research into innovations in the other sectors such that by 2040 or 2050, we have affordable solutions for those sectors as well. I think the rich countries have a few responsibilities. One, they need to get domestic emissions down, but I think the other role that they play is that they need to drive down the cost of these technologies for middle- and low-income countries. Middle- and low-income countries cannot face the dilemma of, “Do I lift people out of energy poverty?” Or “Do I keep my carbon emissions low?” But the role that rich countries can play is to drive down the cost of these technologies such that there’s no trade off. The cheapest technologies are also the low-carbon ones. I mean, that’s one additional way by which rich countries contribute beyond just the climate finance mechanism. 

BILL GATES: Yes, I totally agree with that. In fact, I talk about the cost as the so-called green premium. That obligation not only to get to zero, but to drive those costs down so the trade-offs for say, in India, allow them to say, "Okay, we’re going to build basic shelter," while not dramatically increasing their emissions. The solution that helps with basically every environmental issue is as you get richer, your population growth tends to go down, and then your ability to detect forest fires, or build buildings that, when there are natural disasters, the death toll goes down. And you had that incredible graph of how, particularly in rich countries, the deaths from natural disasters comes down so dramatically, which is actually not about reducing the tornadoes, floods, earthquakes, but rather, it’s about having some warning systems and resilience to those negative effects. 

HANNAH RITCHIE: The declining trend in disaster deaths was really surprising to me. I thought that to be an informed citizen, I had to be watching the news all the time. That’s how I kept up with the world. But when you watch the news, all you see is disaster, disaster, disaster. And if you had asked me to draw the trend of what was happening to disaster deaths in the world, I would have said that they were at the highest level ever. Actually, when you step back to look at the data it is the opposite. Because of increased resilience, we’ve seen a really, really dramatic decline. 

BILL GATES: If you look out at 2100 a lot of the models look pretty hopeful because during that timeframe you have a lot of economic growth. 

HANNAH RITCHIE: Yes, I mean, the way I see it is we do have the capacity to adapt. We have the capacity to make our buildings, our infrastructure, more resilient. I think the key there is that we need to make sure that this is inclusive globally. It’s going to be the poorest who are going to be hardest hit by this because they don’t have the resilience to build back. 

BILL GATES: Yes, so to be clear, your message is although being a doomer is not the right way to look at this, the sense of urgency about all the different areas that you talk about in the book is still super-high. You would love to see us making even faster progress.

HANNAH RITCHIE: Yes, I mean, the whole point of the book is that these are big and urgent problems, and we need to really get moving on them. What I’m trying to push back against is more the message of, “It’s too late, we can’t do anything about it.” I think, for me, we’ve seemed to have flipped very quickly from this area of fringe denial, where the denial sphere was actually quite loud and quite big, and we’ve suddenly seemed to flip straight into, “It’s too late and there’s nothing we can do about it.” And the key message of my book is that these are hard problems to solve, but I think we are capable of solving them. And it’s just not the case that it’s too late to tackle this.

BILL GATES: Well, I’m certainly going to be sending it to lots and lots of people. Just like in global health we need to tell the stories of how great progress has been because there are lessons out of that, and we keep people engaged, even though the pandemic was a big setback. It’s easy in any of these areas, including global health, to feel really like, “Oh, we’re not making that much progress.” And so to have the positive data points be in there and have it be kind of comprehensive I think is fantastic. I’m looking forward to all the debates that it will generate.

HANNAH RITCHIE: I wouldn’t have an impactful book if everyone just loved it and just loved everything about it. It’s meant to generate discussion. If we’re having discussions based around the data, which I’ve tried to present in the book, then I think I’ll have achieved something. A cool part of the book is not just saying, “Hey guys, everything’s fine, we can just sit back.” It’s a call to action. It’s about trying to show where we are, building on the momentum that we’ve gained through tackling some of these problems, but also trying to show what we need to do next. Well, I hope that it will inspire more action rather than reduce the pace of it.

[music] 

BILL GATES: I’ve got a turntable here, and like I do with all the guests, I asked if you could bring along a record that means something to you. So tell me about it. 

HANNAH RITCHIE: Yes, I mean, I should caveat this by saying this is not mine. If you’re under the age of 30 and you have vinyl, you’re cool, and I didn’t meet the cool criteria. So, I had to raid through my dad’s collection. But the one I have here, the track is called “Life is Grand” by a band called Camper Van Beethoven. Do you want me to play it for you? 

BILL GATES: Sure. 

[music – “Life is Grand” by Camper Van Beethoven] 

HANNAH RITCHIE: I think part of why I chose it is, if you ask me, at any point in human history, when I would want to be born, I would still choose today. Despite the environmental crises we face, I think this is the best time to be alive as a human. I want to make people feel more hopeful about the future that we can build. And I know that that will get some pushback from environmentalists, but it’s fine. I’m trying to create discussion. That was why I chose that track. My dad would play vinyl when I was younger. It’s quite poignant that I brought one of my dad’s tracks, because I think he’s played a big role in shaping, not necessarily what I think but how I think. I remember as a kid he would always play devil’s advocate. So regardless of what opinion I took, he would counter that with a different opinion, even if he agreed with me. And at the time as a kid, I found it really annoying and frustrating. But I think he really taught me how to think about things in different ways, and I think that’s part of how I think today. Like, the problems that we’re facing are complex, they’re not one dimensional. You need to look at it from different angles and through different disciplines to tackle them. I think the way that he set me up of how to think has been really important.  

BILL GATES: Fantastic. 

HANNAH RITCHIE: So when I’m delving into a new topic, I always try to be really curious about it and come into it with an open mind. And I think from that needs to come a willingness to change your mind when the evidence changes. I mean, that’s what science is. Is there something that you’ve changed your mind about recently? 

BILL GATES: I spend a lot of time in the technology world, and I have to say, I was very stunned how the AIs went from basically not being able to read or write at all, to doing that in a very facile way. Still very imperfect, but it kind of blew my mind. I had challenged people to pass a test and thought they might never, or at least it would take them years, but within a few months, they were able to do it. So now I’m thinking about, “Wow, how do we use this in education, in health, and in various environmental challenges?” So the power of these AIs, I missed predicting that, and I’m reformed. 

HANNAH RITCHIE: Do you think AI will play a role in climate action?  

BILL GATES: Well, absolutely, because our ability to model complex phenomena, the AIs are helping a lot with that. For example, looking at the genetics of cows, and saying, “Hey, some cows emit a lot of methane, and some emit very, very little and some cows survive in hot weather very well, and some do not.” And with our ability to edit genes, one of the most dramatic sources of emissions, that at one time I wasn’t sure the path forward, now we can see either making the cows better, or various techniques where they create meat without the cow. So the power of AI to look at those genes and see the patterns, even the weather modeling piece, now AI is being applied to that, both the long term, which is kind of those climate models, but say, telling the farmer in Africa based on the weather, should they go ahead and plant now, or is it going to be so dry. They used to always plant at the first rain. But if you know that’s anomalous, then you shouldn’t plant. And so the AIs are really starting to help us with very practical problems. For you, what’s an area where new data kind of changed your view of things? 

HANNAH RITCHIE: My general framework for change on many of these technologies is that if you generate alternative technology, which is as good as the original and is cheaper than the original, then people will just adopt it. I think that’s true for energy sources. I think people are not that bothered about what actually goes into the plug, they just want reliable power. I think one area where I’m a bit more skeptical of that framework now is in food. Now, I’m a big fan of meat substitutes. I love Impossible Burger and Beyond Meat burger. I’m a vegan, so I eat this stuff all the time. I think I had this framework in my head that if they just got cheap enough and tasted good, that people would just make that switch. I’m now becoming much more skeptical that it will be as easy as that. I think there will just be this inherent resistance for many people that it’s not meat so I’m not going to make the switch. So, to me, I’m leaning more towards, I think if we’re going to see this large-scale change in dietary habits, you basically need to generate meat, which would be lab grown meat, for example, where it’s not just a plant-based substitute for that, but it’s the actual thing, just without the cow or the chicken. 

BILL GATES: Yes, you’ve got three ways to solve that. Make the cow better, but even then, you have the ethical issues there, or people who use plant material where they haven’t succeeded in matching the taste or the cost. I know they have new generations coming, so I’m hopeful that it will improve. But as you say, the cell-based approaches, they’re not going to have a problem with the taste. Their challenge is very much the cost. But there are some great companies, including one called Prolific, and it looks like we may get there. Sometimes the path is a lot longer and we underestimated how easy it would be for people like Beyond and Impossible to become mainstream, but they’re out there doing new versions. So I’m still hopeful. In this meat substitute area, is there a product that you’ve found attractive?  

HANNAH RITCHIE: I was a vegetarian for years, and last year I went vegan. I’m a big fan of meat substitutes. I think the one that’s my ultimate favorite is the Impossible Burger. And I had it, must have been 2019, when me and my team were in San Francisco for a few months. But you can’t get it in the U.K.  

BILL GATES: Oh, really? 

HANNAH RITCHIE: Yes, so when I had the Impossible Burger, I think that was a real flip back to the sensation and taste of actually eating a burger. It really reminded me of what an actual beef burger tasted like, and I hadn’t had one for years. But yes, unfortunately we don’t have Impossible Burger yet in the U.K. I think my ultimate favorite there is Beyond Meat. I think the taste is really good. The texture is really good. I’m sure many meat eaters would disagree that it doesn’t quite match the experience for them. But, for me, it’s really good. What about you? 

BILL GATES: I have to say sausage is an area where it seems to be easier for them to create something where I can’t tell the difference, or like a chicken sandwich. Ground beef, they are pretty close, particularly because you have salt and sauces on it. The ultimate might be a steak, although there are companies who say that even that they’ll be able to achieve something. Almost every type of food—milk, cheese—there’s interesting work going on. And so if you can get say beef or pork to be made this way, amazingly that would even help with things like deforestation because there’s a whole chain of how those animals get fed. I keep trying this stuff. There’s a yogurt that I think is absolutely fantastic.  

HANNAH RITCHIE: I think we’re pretty far away on fish. I haven’t yet tried a meat substitute for fish that really matches the taste. 

BILL GATES: Yes, for fish there’s this big trend away from ocean-based fishing to so-called aquaculture. And that started out as a very environmentally insensitive thing, but now they’re really improving what they do with their wastewater, and how they control disease. It’s interesting that we’re almost to the point where half of the fish come from aquaculture. And, at least in Africa, the upside to having a lot more of that is there. It’s not a fish substitute, but it’s just another way of growing the fish. 

BILL GATES: If you had the opportunity to ask somebody who had time traveled back from 2100, what would be your top questions for them? 

HANNAH RITCHIE: I think one of my top questions would be, what share of the world is living on less than $20 a day? I think, for me, looking into the future, what I want to see is a world where most people, or everyone in the world, is living a comfortable life. Now, we can capture that with extreme poverty rates, which is basically a few dollars a day. Those poverty lines are extremely low. I’d want to know how many people are able to live on $20 a day, or $30 a day, which is kind of the poverty line in rich countries. Now, if low- and middle-income countries are managing to reach that level of income, I think that would be an amazing achievement. To me, that would signal several things. I mean, one, just that question would signal, if we have made progress on health, agriculture, poverty. Because I think all of those issues are linked. I think in countries where most people are above the poverty line, you have generally good health outcomes. You probably also have really productive agriculture. I think it would also tell you something about how well we have tackled environmental problems. If that was the case, then my assumption would be that climate change hadn’t had extremely devastating impacts, where agriculture was ruined and health outcomes were really poor, and people were plunged into poverty. I think if I was able to ask one question, that’s what it would be. 

BILL GATES: No, I think that’s pretty smart because yes, in the end, it’s all measured through human welfare. It’s not like the end goal is less plastics or even a certain temperature. It’s “Are humans thriving?”, which is very much what the Gates Foundation tries to prioritize. I have to say, if I met this person, I’d sort of want to say, how are you generating energy, is it fusion or fission or some unexpected thing. And then understand how the AI was either helping them come together to be less polarized, or how they dealt with that challenge. But you’re right, the report card isn’t the tactics. It’s the quality of life. 

HANNAH RITCHIE: Yes. 

BILL GATES: So what do you do to relax when you’re not working so hard? 

HANNAH RITCHIE: I’m really into exercise. I like running and going to the gym, and I do a lot of bouldering, which is like climbing without ropes. I think, for me, exercise is really key. I think the caveat there is that often I’m still a little bit working. I think often when I’m running, I’m getting really good ideas. And often I’ll think through an article that I’m writing while I’m running. But I guess, for me, it’s a good idea generation tool. I think, for me, sport is a big thing. How about you? 

BILL GATES: For me, it’s tennis and pickleball. I probably should do more running or exercise things. I do some of that. But tennis is a lot of fun. I have a lot of friends that it’s a healthy activity and a good distraction from work.  

BILL GATES: Well, thanks for joining me, Hannah. I really enjoyed our conversation. 

HANNAH RITCHIE: No, thanks very much for having me. It was a really fun chat. 

[music] 

BILL GATES: Unconfuse Me is a production of the Gates Notes. Special thanks to my guest today, Hannah Ritchie. 

[music ends] 

BILL GATES: I love forcing myself to write, although it takes a lot of discipline. 

HANNAH RITCHIE: For me, I also have a day job. So, for me, I’m a very early morning writer. I get up at 4 or 5 a.m., and that’s when I’m really productive in my writing.