Not All Hydropower Is Climate Considerate

并非所有的水电都考虑到了气候

Solar. Wind. Hydropower. These renewable energy sources are all much better for the climate than fossil fuels, right? Well, yes for wind and solar. But it turns out that the picture for hydropower is more complicated than we think.

太阳能。风。水力发电。这些可再生能源都比化石燃料对气候更有利，对吗?是的，风能和太阳能。但事实证明，水力发电的前景比我们想象的要复杂得多。

A new study by the Environmental Defense Fund analyzed the climate impacts of 1,500 hydropower facilities across the globe. That accounts for about half of hydropower generation worldwide. The researchers looked at whether the facilities behave as a greenhouse gas sink or as a source. To figure this out, they investigated all the different components that help determine a hydropower facility;s greenhouse gas emissions.

美国环境保护基金会的一项新研究分析了全球1500座水电设施对气候的影响。这占了全世界水力发电的一半。研究人员观察了这些设施是作为温室气体汇还是作为温室气体源。为了找出这个问题的答案，他们调查了所有有助于确定水电设施温室气体排放量的不同组成部分。

There are so many factors that contribute to greenhouse gas emissions from hydropowerbut essentially the majority of greenhouse gas emissions arise from the reservoir itself, as vegetation and soils are submerged underwater in the dam that is used for the hydropower generation. Ilissa Ocko, a senior climate scientist at the Environmental Defense Fund and co-author of the study. As the submerged vegetation decays, it releases methane or CO2.

水力发电造成温室气体排放的因素有很多，但从本质上讲，大部分温室气体排放来自水库本身，因为用于水力发电的大坝的植被和土壤被淹没在水下。环境保护基金的资深气候科学家、这项研究的作者之一伊丽莎奥科(Ilissa Ocko)说。当水下植被腐烂时，会释放出甲烷或二氧化碳。

The larger the surface area of the reservoir, the more greenhouse gases are going to be emitted from that reservoir. Also the temperature plays a role as wellhow warm the reservoir is will affect how much greenhouse gases are produced and emitted from the reservoir.

水库的表面积越大，水库排放的温室气体就越多。此外，温度也起着一定的作用水库的温度将影响水库产生和排放多少温室气体。

Through their analysis, Ocko and her co-author Steven Hamburg, also with the Environmental Defense Fund, discovered that the climate impacts of hydropower run the gamut. The good news is that some facilities perform just as well as wind and solar. But shockingly, more than 100 facilities are actually worse for the climate than fossil fuels. The study is in the journal Environmental Science Technology.

通过他们的分析，Ocko和她的合著者Steven Hamburg(也是环境保护基金的一员)发现水力发电对气候的影响是全方位的。好消息是，一些设施的表现与风能和太阳能不相上下。但令人震惊的是，100多座设施对气候的影响竟然比化石燃料还要严重。这项研究发表在《环境科学与技术》杂志上。

This finding doesn;t mean we should forget about hydropower.But we just need to be careful to make sure that we have climate benefitsthere are a lot of situations where hydropower can be on par with wind and solar. So it really depends on the specific facility.

这一发现并不意味着我们应该忘记水电。但我们需要小心确保我们能从气候变化中受益在很多情况下，水力发电可以与风能和太阳能并驾齐驱。所以这取决于具体的设施。