美国还能领导气候行动吗
Amid much optimism the UN declared last week the world was on course to pass the threshold necessary to put the Paris climate change deAl into effect.
上周，联合国(UN)颇为乐观地宣布，全球即将迈过让巴黎气候变化协议生效所需要达到的门槛。
More than 55 countries have joined the agreement, representing about half of all global emissions.
超过55个国家加入了该协议，它们的温室气体排放量约占全球的一半。
Yet that milestone could almost instantly be undone if the US courts reject President Barack Obama’s clean energy plan.
然而，如果美国法庭否决巴拉克•奥巴马(Barack Obama)的清洁能源计划，这一里程碑几乎瞬间就会倒塌。
A group of Republican states and energy companies say Mr Obama’s methods, which aim to cut US carbon emissions by more than a quarter within a decade, are unconstitutional.
能源企业以及共和党控制的多个州表示，奥巴马使美国碳排放量在10年内减少逾四分之一所采用的方法是违宪的。
The hearings start on Tuesday.
听证会于周二开始。
At question is the courts’ view of the scope of Washington’s regulatory powers.
法庭对联邦政府监管权范围的看法是问题所在。
At stake is US leadership on climate change — and the viability of the Paris deal itself.
但其结果将关系到美国在气候变化方面的领导力以及巴黎气候变化协议本身的存续。
The objections are deceptively abstruse.
反对的理由看上去深奥，其实不然。
Opponents of Mr Obama’s plan say he has overstepped his powers by requiring US states to cut their carbon emissions.
反对奥巴马计划的人士表示，奥巴马要求各州减排是越权之举。
They claim this over-interprets the Clean Air Act, which gives Washington’s Environmental Protection Agency the power to regulate local pollutants, such as mercury and sulphur.
他们声称，这过度解读了《清洁空气法案》(Clean Air Act)，该法案赋予美国环保署(Environmental Protection Agency)监管本地污染物的权力，例如汞和硫磺。
They also say Mr Obama’s plan violates the US constitution which bans the federal government from taking control of state resources.
他们还表示，奥巴马的计划违反了美国宪法，因为宪法禁止联邦政府控制州的资源。
Courts have ruled that carbon dioxide is a pollutant and thus within the EPA’s scope.
法庭已裁定，二氧化碳是污染物，因此在环保署的监管范围之内。
But the plaintiffs say Mr Obama is misusing even this authority by setting broad mandates, which gives states the latitude to decide how to reach their goals.
但原告们表示，奥巴马即便对这项权力也使用不当，他设定了宽泛的任务框架，让各州自由决定如何达到它们的减排目标。
Under this narrow reading, Mr Obama should only have scope to shut down precisely defined sources of pollution.
根据这种狭隘的解读，奥巴马只应有权关闭精确界定的污染源。
The objections are unconvincing both on practical and legal grounds.
无论从现实还是法律的角度来看，这些反对意见都是没有说服力的。
The president is surely right to say that, within a broad framework, the states are best placed to draw up their plans since they have a clearer grasp than Washington of local energy needs.
奥巴马表示，在一个广泛框架下，由各州拟定各自的计划是最合适的，因为它们比联邦政府更了解本地能源需求。
Some may choose to keep their coal-fired plants open and make up ground with stringent energy efficiency codes.
奥巴马这么说无疑是对的。一些州可能选择让燃煤发电厂继续运营，代之以严格的能效规定。
Others may wish to do the opposite.
还有一些州可能希望采取相反的措施。
Either way, if the objections are upheld, Mr Obama would be forced to spell out case by case how states should comply with the mandate.
不管是哪种做法，如果上述反对意见得到支持，奥巴马将被迫一个一个地提出各州应如何执行减排任务的计划。
The result would be the same.
结果是一样的。
But the means would be far more intrusive.
但做法会更具干预性。
It is possible the court could throw out the plan altogether on constitutional grounds.
法庭有可能以宪法为由彻底否决该计划。
But that is unlikely.
但可能性并不大。
The legal basis for US federal leadership has been established.
美国联邦政府的领导权是有法律依据的。
Even if Mr Obama’s plan survives the courts intact, it would be rendered moot were Donald Trump elected in November.
即便奥巴马的计划完整无缺地得到法庭允许，但如果唐纳德•特朗普(Donald Trump)在11月当选，它也就毫无意义了。
Mr Trump has vowed to pull the US out of the Paris deal and reverse Mr Obama’s executive actions to reduce carbon emissions.
特朗普发誓将让美国退出巴黎气候变化协议，并废除奥巴马在减排方面的行政做法。
By contrast, any modification of Mr Obama’s plan would be manageable were Hillary Clinton to win.
相比之下，如果希拉里•克林顿(Hillary Clinton)当选，即便她对奥巴马计划有所修改也会是可控的。
Her administration could reconfigure the means to cut US emissions without diluting the target.
她的政府可能会在不降低目标的情况下调整减排手段。
Both the legal challenge and the high-stakes presidential election underline the fragility of US leadership on global warming.
法律挑战以及关系重大的总统大选都突显了在全球气候变暖问题上，美国领导力的脆弱性。
That will remain true as long as Congress refuses to pass legislation that would put a price on carbon. The chances of that happening remain slim in the near future.
只要美国国会拒绝通过征收碳税法律——在近期内立法的可能性很小——这种局面就不会改变。
That should not stop supporters of market-based reform from making the case more forcefully on Capitol Hill.
这不应阻止支持市场改革的人士在美国国会提出更有力的理由。
The US is on course to fulfil about two-thirds of its carbon emission cuts by 2025 because of its switch to shale gas and fracking, and stricter vehicle emission rules.
由于转向页岩气和压裂法并实施了更严格的汽车排放规定，美国有望到2025年完成大约三分之二的减排目标。
All this is happening anyway.
不管怎样，这一点是现实情况。
What is at stake is not the shifts in US energy patterns but the question of American leadership.
目前重要的不是美国能源模式的转变而是美国领导力的问题。
Other countries will act more decisively if US is seen to be taking the lead.
如果看到美国发挥表率作用，其他国家将采取更果断的行动。
