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中美“应对气候变化共同声明”的意义

迈克尔李维 美国外交关系协会优乐娱乐注册安全与气候变化项目部总监  2015年01月16日

【摘要】中国此次同美国一起宣布新的目标,显然表示中国开始愿意把自己视为是全球努力的一部分。如果没有新的立法,美国方面的目标看上去是很难实现的,但这并不意味着新目标无法实现。任何实现新目标的努力都在很大程度上依赖于减少非二氧化碳气体的排放,并且增加美国的碳汇水平,同时要实现这些目标还需要改变执行美国环境保护局发电厂相关规定的方式。中国计划的真正规模显然有着更大的不确定性。


奥巴马与习近平昨天晚上让所有专家都吃了一惊,他们宣布中美达成新的减排计划。这是两国数年合作失败后一次巨大的外交突破。双方的优乐娱乐注册合作已经突破了清洁优乐娱乐注册部分,涉及到了气候变化中最敏感的部分。这对全球减排而言将有何影响和意义将在未来几年内显现。

这一协议的重要性体现在哪里?也许我们仍然需要时间确定两国计划的细节。不过已经可以确定三个方面的重要影响。

中国现在在全球气候变化问题上的外交方式正变得和过去不一样,而且更富建设性。中国承诺将于2030年左右达到排放峰值,并将努力提前。中国也明确表明了扩大非化石优乐娱乐注册的使用占到中国全部优乐娱乐注册的20%。人们也许重点关注这些数字(这些我后面也会提到),但是也许最令人惊讶的是这样的数字完全是新的。2009年中国曾经宣布在2020年前将把碳排放强度相比2005年的水平减少40%-45%。包括我在内,许多分析人士都认为中国对2020年后的减排没有任何计划。但这一次不一样了。中国明确表示将在2030年达到排放峰值,这同许多专家认知和期待的有很大的差别。这本身就很有意义。

中国逐渐制定并宣布这些目标的方式和过程就和这些目标的本质一样重要。

中国显然已经不再强调气候变化问题上自身的独立性。这样的思维方式导致中国往往倾向于以单边方式宣布自身的主要减排目标——即使在此之前和美国有过沟通。中国此次同美国一起宣布新的目标,显然表示中国开始愿意把自己视为是全球努力的一部分。

这是很关键的一点。习近平似乎对守成大国和崛起大国在历史上的冲突非常敏感。在中美两国广泛的冲突中,气候变化越来越成为一个具有建设性意义的对话领域,这值得大书特书。中美两国的共同声明体现了这一点。

人们也许还很关心究竟是什么国内因素起了作用。一个可能的解释是习近平希望中国在气候变化问题上所做出的转型以达到减排目标同他在其他经济和战略问题上所希望中国做出的转型是一样的(例如减少空气污染)。做出一个坚定的国际承诺将有助于他强化自己破除国内障碍的空间。

如果没有新的立法,美国方面的目标看上去是很难实现的。美国承诺将到2025年将碳排放总量相比2005年下降26%,并且努力达到28%(请注意美国的承诺方式和中国很像)。如果美国能够实现现在的目标到2020年排放水平相比2005年下降17%,那么从2020年到2025年期间,美国的平均年度减排量需要达到2.3%-2.8%,这将大大超过现在的幅度。这是一个强有力的很苛刻的目标。按照现在的法律现状是非常具有挑战性的,不过美国政府表明这是可以实现。

我个人的理解是,这一数字是经过自下而上的对美国经济的分析以及对美国未来立法前景的预期后得来的。技术上说一个可行的标准是《瓦克斯曼-马凯气候变化议案》,该议案要求美国在2025年减排30%,不过这其中一大部分都希望通过国际补偿的方式实现。新的法案要比这一法案在国内减排目标上更有野心。

当然,这并不意味着新目标将很难实现。过去五年,全世界都发生了很多变化。我将详细解释这些变化。

非常直接的一点是任何实现新目标的努力都在很大程度上依赖于减少非二氧化碳气体的排放,并且增加美国的碳汇水平(这一点已经超出了政策本身的影响范围)。这是非常显然的,因为26%的二氧化碳减排量意味着在2025年需要削减发电厂煤炭使用量的75%(不包括可能在未来发生的激进的意料之外的电力传输方式的改变)我能理解一些人警告应当在依赖非二氧化碳温室气体减排的问题上保持谨慎。在这样的情况下,也许美国政府将一切情况下所能做到的最好状况同时计算在内了。

同样值得注意的是要实现这些目标还需要改变执行美国环境保护局发电厂相关规定的方式。尤其未来放松汽车节能规定的问题上更是如此。美国环保局现在正在制定的有关发电厂的规定已经遭到了多方的阻挠,继续在这一问题上施压将面临很高的政治和技术风险。尤其是,这一系列的目标不可能仅仅在奥巴马政府内得以实现。奥巴马政府也许能够制定并就相关的数字进行谈判,但奥巴马的继任者将决定这些目标能否实现。

有关美国的目标还有最后一点:这一目标具有一定的难度并不意味着这个目标不好。有难度的目标能够推动决策。在2009年几乎没有人相信美国的碳排放可以在2020年相比2005年的水平下降17%,但现在看来这完全是可行的。当然,大数字可能引发社会的不满和阻力,这是需要注意的。

中国计划的真正规模显然有着更大的不确定性。美国目标中26%和28%的基本等于1亿2千万吨的二氧化碳排放,这低于美国优乐娱乐注册信息署预估的中国2025年到2030年之间的平均碳排放增长。宽松的说,中国提前一年实现排放峰值所能产生的影响和美国实现26%或28%的目标的差别所产生的影响是一样的。

随后的问题就不仅仅是中国何时达到二氧化碳排放的峰值,而是峰值在哪里。究竟是高于现有水平25%、15%还是10%?这对全球碳排放将造成很大的不同。我认为我们也许能够从中国宣布的零排放优乐娱乐注册使用目标上得出一些推断(未来我将就此再写一篇文章)。至少如果明年中国宣布了碳排放强度减少目标后(中国今年9月在联合国气候变化会议上是这么表示的),我们就能有一个基本的判断。另外一个我们可以推测出一些信息的是清华大学和麻省理工学院最近做了一个模型,假设中国将于2030年达到碳排放的峰值。他假设要实现这一目标需要38美元/吨的碳排放税,最终的结果是高于现有排放水平17%。这一研究应该也是中国政府参考的研究模型之一。

我不认为未来有关中国和美国的减排目标还会有进一步的讨论,尽管欧洲领导人似乎还希望进行一些讨论。明年,各方与其就所谓的减排指标喋喋不休,还不如关心三件事情:中国的计划具体将包括哪些内容?美国的目标将在政治上如何实现——能否吓阻国会减少对美国环保局正在制定的相关规定的干预?以及最重要的是,中美此次所展现出的五十外交和做是否能够为全球气候变化外交带来新的变化——各国能够从争论减排数字上解放出来?


 

 

What the Big U.S.-China Climate Announcement Means


Michael Levi


Barack Obama and Xi Jinping surprised even the closest climate watchers last night when they jointly announced new emissions-cutting goals for the United States and China. This is a serious diplomatic breakthrough after years of unsuccessful efforts to do something big and joint that goes beyond clean energy cooperation and gets to one of the most sensitive parts of climate policy. What it ultimately means for emissions, of course, will be determined over many years.

 

What exactly is the significance of the news? It will take time (and fleshing out of details) to fully assess the two countries’ proposals. But there are already three big takeaways that can be discerned.

 

China is now approaching international climate diplomacy differently from – and more constructively than – before. The Chinese announcement promises to peak emissions “around” 2030 and to try to beat that deadline. It also articulates a goal of boosting non-fossil energy to twenty percent of Chinese fuel. People will pore over these numbers (and I’ll say something about them below). But perhaps the most striking thing about them is simply that they’re genuinely new. In 2009, when China announced a goal of cutting emissions intensity by 40-45 percent below 2005 levels by 2020, many analysts (myself included) noted that they contained no ambition to move beyond “business as usual” estimates for future Chinese emissions. Not this time around: for China to peak its emissions by 2030, it would need to depart significantly from the path that most analysts currently expect. That alone is a big deal.

 

The way that the Chinese goals were developed and announced, though, is as important as their substance.

 

China has typically gone out of its way to assert its independence in anything climate-related. That approach would usually have led it to announce major goals like these in a clearly unilateral context – even if they were developed in tandem with the United States. Rolling them out together with the United States says that China is increasingly comfortable being seen to act as part of an international effort.

 

Indeed that may be part of the point here. Xi appears at least somewhat sensitive to historical patterns of conflict between established and rising powers. Amidst broad tensions between the United States and China, climate change is increasingly an area of relatively constructive dialogue, which makes it worth highlighting. A joint announcement does exactly that.

 

One also has to wonder what domestic dynamics are at work here. One plausible theory for why Xi made the announcement in an international context is that the transformations he seeks in order to achieve Chinese climate goals are also ones he wants to pursue for other economic, environmental, or strategic reasons anyhow (for example, reducing local air pollution). Making a firm and international commitment to this can strengthen his hand against those at home who oppose such moves.

 

The U.S. target looks like it’s going to be really tough to meet without new laws. The United States promised to cut emissions 26 percent below 2005 levels by 2025 and to try to get to a 28 percent cut. (Notice a pattern – baseline and stretch goals – between the United States and China?) If the United States hits its current target – 17 percent below 2005 levels by 2020 – on the head, it will need to cut emissions by 2.3-2.8 percent annually between 2020 and 2025, a much faster pace than what’s being targeted through 2020. That is a mighty demanding goal. It will be particularly challenging to meet using existing legal authority – which the administration says can be done.

 

My understanding is that the numbers were arrived at through careful bottom-up analysis of the U.S. economy and of legal authorities over an extended period of time. But technically possible and politically likely are two different standards. One useful point of comparison is the Waxman-Markey legislation. That bill would have required a 30 percent emissions cut by 2025, but a large slice (perhaps more than half) of the reduction was expected to be met through international offsets. The new targets thus far exceed Waxman-Markey in domestic ambition.

 

That doesn’t prove, of course, that the new targets will be tough to meet; the world has changed a lot in the last five years. So let’s drill down on some details.

 

One thing that’s straightforward to infer from the announcement is that any effort to meet the new goals will need to lean disproportionately on measures to reduce emissions of non-CO2 gases and increase the U.S. carbon sink (the latter of which is mostly beyond the influence of policy). This is clear once one observes that a 26 percent cut in CO2 emissions in energy alone would require slashing power plant coal use by somewhere around 75 percent by 2025 (barring some sort of radical and unexpected change in the transportation sector). I would normally sound a major warning note on reliance on cutting non-CO2 gases, since it’s wrong to trade cuts in carbon dioxide for cuts in shorter-lived forcers. In this case, though, it’s probably wrong to look at this as a set of tradeoffs; instead the administration appears to be putting forward the most it thinks it can do on all fronts.

 

It’s also worth observing is that achieving these goals will almost certainly require changes to the implementation of the EPA power plant regulations. This would be particularly true if the automobile fuel economy rules are relaxed when they’re reviewed in a few years. The EPA power plant rules as they’re currently proposed are already spurring plenty of pushback; pressing them further will be a tall political and technical task. In particular, it’s near-impossible to imagine achieving these goals simply with actions taken during the Obama administration. President Obama’s administration may have developed and negotiated these numbers, but his successor will determine whether they’re achieved.

 

One last note on the U.S. numbers: The fact that they’re a stretch doesn’t mean that they’re bad. Stretch goals can motivate policymaking. And few people thought, back in 2009, that the United States could cut emissions 17 percent below 2005 levels by 2020 using existing authorities, something that’s now seen to be perfectly feasible. Big numbers can, however, create big backlash, which is something to watch out for.

 

The potential scale of the Chinese plan, though, dwarfs all of this – as do the associated uncertainties. The difference between a 26 and a 28 percent cut in U.S. emissions is on the order of 120 million metric tons of carbon dioxide emissions annually. That’s smaller than the EIA’s projected annual growth in Chinese energy emissions for each year between 2025 and 2030. Very loosely speaking, a mere one-year shift in the Chinese peaking year could matter at least as much to global emissions as the difference between the various U.S. targets that have now been announced.

 

And then there’s the matter not of when Chinese emissions peak but where they peak. Do they peak 25 percent above current levels? 15 percent? 10 percent? That makes an enormous difference for global emissions. I suspect that one can make some inferences from the target for zero-emissions energy that the Chinese announced; perhaps more on that in another post. At least one big hint at where Chinese leaders hope to land should come next year if they announce a carbon intensity target (something they seemed to indicate was in the works at the UN in September). One way of getting some insight might be from a recent MIT-Tsinghua study that models a scenario with Chinese peaking in 2030. It uses a $38/ton carbon tax to get there and peaks at 17 percent above current levels. It would not be a surprise if that analysis was one of many that informed Chinese decision-making.

 

I wouldn’t expect much more negotiation over either U.S. or Chinese targets, even though European leaders may want to have a discussion. Over the next year, rather than focus on any haggling over emissions numbers, it will be worth watching three things. What will the remaining details of the Chinese plan look like? How will the U.S. goals be received politically – and could they spook a Congress currently considering how much to try to interfere with pending EPA regulations? And, perhaps most important, could this display of pragmatic U.S.-China diplomatic cooperation be a sign of more to come in international climate change diplomacy – which will need to go well beyond target-setting – over the coming year?



 
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