经济学人下载:核能,烟雾消散之后

To put that in perspective, in 2010 the UN Environment Programme estimated that for the world to have a reasonable chance of limiting global warming to less than 2°C, carbon-dioxide emissions should be reduced to 44 billion tonnes by 2020. With business as usual, emissions would be between 54 billion and 60 billion tonnes. If countries took the most ambitious of the courses of action that they have outlined to the UN, the figure comes down to about 49 billion tonnes, leaving an “emissions gap” of 5 billion tonnes that seems highly unlikely to be bridged. So the 2 billion tonnes saved by nuclear power is not vast, but it is significant.

其中的意义在于，联合国环境规划署曾在2010年进行估算，若想让世界有合理的机会将全球变暖的幅度限制在2摄氏度以下，则二氧化碳排放量应当在2020年时被削减至440亿吨。若按正常状况计算，排放量将在540亿吨至600亿吨之间。如果各国在其向联合国列出的各种行动路径中选取目标最为宏大的一种，则这一数字将降至490亿吨左右，而这将留下似乎很难弥合的50亿吨“排放缺口”。因此，核能所节约的20亿吨数量虽不巨大，但意义却颇为重大。

That said, a complete withdrawal from nuclear energy is not on the cards. Though China, which has 77 reactors at various stages of construction, planning and discussion, has said it will review its programme in the aftermath of Fukushima, few expect it to stop entirely. China has a great appetite for energy, which will continue to grow. For now its energy sector is highly concentrated on coal, but so that the country can both diversify and clean its air China’s latest five-year plan aims for growth in all sorts of non-coal energy, including wind power, gas and nuclear. Adverse public opinion and the additional cost of capital caused by uncertainties over regulatory approval have much less salience in China than elsewhere.

这意味着核能不太可能被全面放弃。尽管有77座正处在建设、规划和讨论等不同阶段的反应堆的中国，已经表示将在福岛事故之后重审其计划，但很少有人认为中国将全面停止核计划。中国对能源的胃口极大，而且这种欲求还将继续膨胀。目前，中国能源领域高度集中于煤炭，不过，因为该国既能使能源多元化，又能改善其空气质量，因此中国最新的五年规划以各类非煤炭能源的增长为目标，其中包括风力、天然气和核能。在中国，公众的反对态度以及由获得监管部门批准的不确定性所导致的资本额外成本，其显著意义要远远小于其他国家。

Some other countries will also go ahead: Russia says it sees no reason to stop work on ten reactors that are in development. But there could still be a widespread withdrawal from the technology by OECD countries, caused by national changes in policy or stiffer local opposition. And grand though China’s ambitions are, for now OECD countries produce more than 80% of the world’s nuclear electricity.

其他某些国家也会继续开发核电：俄罗斯表示并未发现停止建设开发中的10座反应堆的理由。不过，经合组织国家却仍有可能因为国家政策变化或地区更强硬的反对而普遍放弃核电技术。而且，尽管中国雄心勃勃，但目前经合组织国家的核发电量超过全球核电总产量的八成。

Analysts at Societe Generale, a French bank, argue that if these rich countries built no more reactors and allowed existing ones to close at the end of their planned lives, an extra 860m tonnes of carbon a year would be emitted, on average, from 2010 to 2030. This may underestimate the impact on the system as a whole, because nuclear plants and large dams are the only broadly reliable sources of baseload electricity that do not burn fossil fuels. Although renewable capacity has been added quickly in some countries, you cannot be sure that the wind will blow or the sun will shine to order. A fair part of this can be smoothed out if the various sources are linked into an electric grid that is sufficiently large, robust and smart, but that does not obviate all the need for baseload.

法国兴业银行(Societe Generale)分析师提出：如果这些富裕国家不再建造更多的反应堆，并让现有反应堆在其设计寿命到期后关闭的话，在2010至2030年间，平均每年将额外排放8.6亿吨碳。这或许低估了它对整个体系带来的冲击，因为在不燃烧化石燃料的基本电力负载来源中，只有核电站和大坝基本可靠。尽管一些国家的可再生能源产能已在快速增长，但人们却不能确定风和阳光能够按需而至。如将不同能量来源联入一张足够庞大、稳健、智能的电网，则此问题能有一大部分得到解决，但这并不会完全消除对基本负载的各种需求。

Most studies assume that in a fully decarbonised electricity system the baseload would come either from nuclear or from fossil-fuel plants fitted with carbon capture and storage (CCS) technology. However, CCS has yet to be demonstrated on anything like the necessary scale, so deploying enough of it to replace existing and expected nuclear plants is a tall order. And a public that was turning against hubristic nuclear engineering might also object to the large-scale storage of a potentially asphyxiating gas beneath the ground, which CCS requires. This “numby” (not under my back yard) attitude has already affected some pilot projects.

大多数研究认定：在一个完全无碳化的电力系统中，基本负载或来自核能，或来自装备有碳捕获和储存(CCS)技术的化石燃料发电站。然而，碳捕获和储存技术尚未在任何与必要规模相类似的设施中得到过演示，因此，部署足量此类装置以替代现有和预期建造的核电站，将会相当困难。此外，已对自负的核能工程技术产生反感的公众，或许也会反对在地下大规模储存一种有潜在窒息风险的气体，而这种大规模储存又为碳捕获和储存装置所必须。此般“别建在我家后院”的态度已经对一些试点项目产生了影响。