走向零碳
重磅氢弹
如何使全球经济脱碳？亨利·特里克斯的答案是大量的清洁电力和向最轻气体的革命性转变

Towards Zero carbon
The hydrogen bombshell
What would it take to decarbonise the global economy? Lots of clean electricity and a revolutionary shift towards the lightest gas, writes Henry Tricks

When your destination is Rjukan, three hours west of Oslo, which in the early 20th century was one of the world’s biggest power plants, alternatives to fossil fuels look even more achievable. This is where one of the best potential zero-carbon options, hydrogen, was produced by hydroelectricity as far back as 1928. Cars powered by hydrogen fuel cells have now started to appear on Norway’s streets, even though there may be much better uses of the gas than powering vehicles over short distances. A Hyundai Nexo, owned by Nel, a Norwegian hydrogen company that traces its roots back to Rjukan, carries a message on its rear window: “Thanks for the ride, dinosaurs! We’ll take it from here.” That could be the motto for the age of decarbonisation. Or it could be extreme hyperbole.
如果你去往奥斯陆西侧三个小时车程的尤坎，化石燃料的替代品看起来就更容易实现了。这里在20世纪初是世界上最大的发电厂之一：早在1928年，尤坎就已经在用水力发电生产迄今最好的潜在零碳选择之一——氢气。由氢燃料电池驱动的汽车现在开始出现在挪威的街道上，尽管比起为短途车辆供能，氢气可能还有更好得多的用处。挪威氢能公司Nel的历史可以追溯到尤坎，它拥有的一辆现代Nexo的后窗上贴着一句话：“感谢恐龙们送了一程！我们就从这接手了。”这可能成为脱碳时代的座右铭，也可能沦为极端的夸张。

Alongside China, Norway has helped supercharge demand for electric vehicles, but it could afford to finance the tax breaks and other incentives because of the immense wealth it derives from oil and gas. Hydrocarbons produced by the state energy company, Equinor, generated 310m tonnes of greenhouse gases in 2017. That was almost as much as the total carbon dioxide (CO2) belched out by Britain, a country with 12 times Norway’s population.
挪威和中国一样，大大增加了对电动汽车的需求，但由于石油和天然气带来的巨大财富，挪威可以负担减税和其他激励措施所需的资金。挪威国家能源公司Equinor生产的烃类在2017年产生了3.1亿吨温室气体。这几乎与英国产生的二氧化碳总量一样多，而英国是挪威人口的12倍。

Torn in much the same fashion between a desire to tackle global warming and a dependence on fossil fuels, the world is moving far too slowly to decarbonise its energy system. Acting on the promises made under the 2015 Paris agreement on climate change could see the world on a path to global warming of 3ºC above pre-industrial levels by the end of this century, rather than the 1.5-2ºC countries agreed to strive for. To stabilise global temperatures, humans must be putting no more CO2 into the atmosphere than they are taking out by about mid-century.
这种同时存在解决全球变暖的愿望和对化石燃料的依赖的矛盾同样撕裂着整个世界，让能源系统脱碳变得太过缓慢。如果根据2015年
巴黎
气候变化协议所作出的承诺行动的话，到本世纪末，全球变暖将超过工业化前水平3℃，而不是各国同意努力争取的1.5℃至2℃。为了稳定全球气温，到大约本世纪中叶，人类必须停止向大气中净排放二氧化碳。

Renewables are advancing, absorbing twice as much investment for power generation as coal, gas, oil and nuclear combined last year. Sales of electric vehicles (EVs) are also gaining momentum. According to Bloomberg New Energy Finance, a clean-energy consultancy, it took 17 months, from mid-2014 to 2016, for the global number of passenger EVs to rise from 1m to 2m. It took just six months this year for them to go from 3m to 4m.
可再生能源正在发展，它在去年吸收了两倍于煤炭、天然气、石油和核能总和的发电投资。电动汽车的销售也在加速增长。据清洁能源咨询公司彭博新能源金融称，从2014年中到2016年的17个月里，全球乘用电动车数量从100万增加到200万辆，而今年仅用了6个月就从300万增加到了400万辆。

Yet last year the global energy system still derived 85% of its oomph from fossil fuels, and the International Energy Agency (IEA), a forecaster, expects global CO2 emissions to reach a new record this year. In order to mitigate the impact of global warming and reduce the air pollution that does serious harm to physical and mental health around the world, the immediate task is to encourage the spread of zero-carbon (“clean”) electricity and battery storage. By some estimates, power supply needs to increase fourfold over the next 30 years. To produce this electricity will require a huge increase in renewables, as well as nuclear power (more likely in the developing than developed world), as well as the use of fossil fuels with carbon capture and storage (CCS). And that is just what specialists call the “easy” part.
然而，去年全球能源系统仍然有85%的能源从化石燃料中获得。预测机构国际能源署（IEA）预计今年全球二氧化碳排放量将创下新纪录。为了减轻全球变暖的影响并减少严重危害全世界身心健康的空气污染，当务之急是鼓励推广零碳（“清洁”）电力和蓄电池。据估计，在未来30年内，电力供应需要增加四倍。要生产这么多电，可再生能源、核电（更有可能在发展中国家而非发达国家推广）以及带碳捕获和储存（CCS）的化石燃料使用都需要大幅增加。而这只是专家所说的“简单”的部分。

Decarbonising parts of the economy where electricity and lithium-ion batteries cannot be easily used, such as heavy transport, heating and industry, will be much harder. In 2014 (the latest year for which figures are available) these “hard-to-abate” sectors produced about 15bn tonnes of CO2, or 41% of the total, compared with 13.6bn tonnes for the entire power sector (see chart). The biggest industrial emitters are cement, steel and chemicals.
要让不易使用电力和锂离子电池的经济部门脱碳会更难，例如重型运输、供暖和工业。2014年（可获得数据的最近一年），这些“难以减碳”的行业产生了约150亿吨二氧化碳，占总量的41%，而整个电力行业的排放量为136亿吨（见图表）。最大的工业排放源是水泥、钢铁和化工。

In order to limit global warming to less than 2°C, total emissions from global energy use across industry alone will have to be 50-80% lower by 2050 than they are now, and as much as 75-90% lower if the rise in temperatures is to be capped at 1.5ºC, according to the Intergovernmental Panel on Climate Change (IPCC), a UN-backed body of experts. Even then, over the course of the century hundreds of billions of tonnes of CO2 will need to be extracted from the atmosphere, in what are called “negative emissions”.
据联合国支持的专家组织政府间气候变化专门委员会（IPCC）称，为了将全球变暖限制在2℃以下，到2050年，全球各行各业能源使用的总排放量必须比现在低50%至80%，如果温升上限定为1.5℃，则需要降低75%至90%。即便如此，在整个21世纪还需要从大气中提取数千亿吨的二氧化碳，即所谓的“负排放”工程。

It is an historic undertaking. In the 200 years from the start of the coal age to 1970, the burning of fossil fuels, flaring and cement-making produced 420bn tonnes of greenhouse gases, mostly CO2, or about 1,200 times the weight of every person on the planet today. Between 1970 and 2011, the amount tripled to 1.3trn tonnes.
这是一项历史性的事业。从煤炭时代开始到1970年的200年间，化石燃料燃烧、废气燃烧和水泥制造产生了4200亿吨温室气体，主要是二氧化碳，相当于当今地球上所有人体重总和的1200倍。从1970年到2011年，这一排放量增加了两倍，达到1.3万亿吨。

CO2 is invisible and odourless, so it is harder to visualise the effects of all of this than for more tangible scourges like sulphur and nitrogen oxides, which cause acid rain. Yet the quantities belched out are staggering. The steel and cement industries each produce more CO2 than any country except China and the United States. For every tonne of cement produced, almost three-quarters of a tonne of CO2 seeps into the atmosphere. Cars and trucks are an even bigger burden on the climate; and knowing how much you produce when you fly can ruin the joy of taking off in an aeroplane. This report focuses on energy-related emissions, not greenhouse gases emitted by agriculture, forestry and other land use. The latter account for about a quarter of total emissions.
二氧化碳看不见摸不着，又没有气味，所以相对于会导致酸雨的硫和氮氧化物等更明显的祸害，它的影响更难想象。然而，其排放量是惊人的。钢铁和水泥行业产生的二氧化碳均超过了除中国和美国外的任何国家排放总和。每生产一吨水泥，会有近0.75吨二氧化碳渗入大气。汽车和卡车对气候的影响更大。而如果你知道自己搭飞机出行时会产生多少二氧化碳，会破坏你飞行的乐趣。本报告重点关注与使用能源相关的排放，而不是农业、林业等土地使用产生的温室气体排放。后者约占总排放量的四分之一。

Each of them has its pros and cons. There are obstacles to making, moving and using hydrogen on a large scale. Biofuels such as ethanol are already blended with hydrocarbons in fuels in places such as Brazil and America, but energy crops compete with the food industry for land, and their cultivation also produces greenhouse gases. Emission-free synthetic fuels rely on lots of hydrogen and carbon monoxide to produce surrogate hydrocarbons, so their development hinges on low-cost supplies of those two gases. CCS, as Mr Davis puts it, elicits a “collective groan” from environmentalists, who see it as life support for the fossil-fuel industry. But it is hard to imagine decarbonisation of industries like cement without capturing the CO2 emitted in flue gases.
每种方法都有其优缺点。大规模制造、运输和使用氢气存在困难。在巴西和美国等地，乙醇等生物燃料已混入了烃类燃料，但能源作物与食品工业争夺土地，而其种植也会产生温室气体。无排放合成燃料依赖大量氢气和一氧化碳来生产烃类替代品，因此其发展取决于这两种气体的低成本供应。用戴维斯的话来说，CCS引发了环保主义者的“集体叹息”，他们视之为化石燃料行业的维生器。但很难想象，如果不靠捕获烟气中排放的二氧化碳，水泥等行业要怎么脱碳。

Some are much closer to commercialisation than others. Those working on decarbonising the energy system have an approximate time frame for their endeavours. They say 2025-35 could see the emergence of battery and hydrogen-powered long-distance lorries, and hydrogen-fuelled residential heating. In the 2030s, synthetic hydrocarbons may be developed for ships and planes. In the 2040s, CCS and hydrogen could be applied at vast scale in industry. By the 2050s there would be full-scale carbon removal, either by massive reforestation or direct capture from the air.
有些方案比另一些距离实现商业化要近得多。致力于使能源系统脱碳的人有一个大致的时间框架。他们说到2025至2035年就会出现使用电池和氢动力的长途货车，以及靠氢燃料供暖的住宅。到2030年代就可能出现为船舶和飞机开发的合成烃类。到2040年代，CCS和氢气可大规模用于工业。到2050年代将会通过大规模再造林或直接从空气中捕获碳排放来实现全面的碳去除。
All this may seem pie in the sky if you live in Africa, or another impoverished region, where the main priority is to satisfy existing energy demand. It will hinge crucially on what government mandates and tax incentives are in place to encourage the shift.

如果你居住在非洲或其他贫困地区，那里的当务之急还是满足现有的能源需求，那么所有这些看起来都像是空中楼阁。关键要看政府的指令，以及有何种税收激励措施来引导这种转变。
Still, this report will argue that the obstacles to decarbonisation of the energy sector are not insurmountable. What is more, they could bring economic benefits. The IPCC estimates that, between 2016 and 2035, the annual cost of keeping the rise in temperature to 1.5ºC would be about $2.4trn, or roughly 2.5% of world GDP. Last year total energy investment was $1.6trn, mostly in coal, oil and gas. Adair Turner, chairman of the Energy Transitions Commission (ETC), a global body, says the additional cost per year of running the hard-to-abate industries with net-zero emissions would be $1.2trn in 2050. “You can be absolutely terrified [by the amount]. But if you could go back to building railways in 1850, I’m willing to bet you would also terrify yourself.”

不过，本报告仍然认为，能源部门脱碳的障碍并非不可克服。更重要的是，它们可以带来经济效益。据IPCC估计，在2016年至2035年之间，将温升控制在1.5℃内的年度成本约为2.4万亿美元，约占世界GDP的2.5%。去年，能源方面的总投资为1.6万亿美元，主要投向煤炭、石油和天然气。全球机构能源转型委员会（ETC）主席阿达尔·特纳（Adair Turner）表示，到2050年，每年以零净排放运营那些“难以减碳”的行业将另外需要1.2万亿美元的成本。“[这个数字]绝对会吓到你。但如果你回到1850年去造铁路，我敢说你也会吓一跳。”
Moreover, none of the technologies involved is new; and, unlike fossil fuels, the more they are used, the more their costs fall, providing an incentive to use them across as many industries as possible. Hydrogen could be the most promising, because it is the best complement to mass electrification and could also be used in heavy transport, heating and industry.
此外，这种转变所涉及的技术没有一件是新的。而且，与化石燃料不同，它们被用得越多，成本就越低，这就会鼓励尽可能多的行业去使用它们。氢可能是最有希望的解决方案，因为它是大规模电气化的最佳补充，也可用于重型运输、供暖和工业。