[(Title)] Methane leaks offset much of the benefits of natural gas, new study says

The U.S.

美国。

oil and gas industry emits 13 million metric tons of methane from its operations each year - nearly 60 percent more than current estimates and enough to offset much of the climate benefits of burning natural gas instead of coal,

石油和天然气工业每年从其作业中排放1,300万公吨甲烷——比目前的估计值高出近60%，足以抵消燃烧天然气而不是煤产生的大部分气候利益，

according to a study published Thursday in the journal Science.

根据周四发表在《科学》杂志上的一项研究。

The higher volumes of natural gas leaking from across the industry's supply chain would be enough to fuel 10 million homes and would be worth an estimated $2 billion, the researchers said.

研究人员称，来自整个行业供应链的天然气泄漏量较高，足以为1,000万户家庭提供燃料，估计价值20亿美元。

The study, led by Environmental Defense Fund researchers and including 19 co-authors from 15 institutions, estimated that the current leak rate from U.S.

该研究由环境保护基金研究人员牵头，包括来自15个机构的19名共同作者，估计美国目前的泄漏率。

oil and gas operations is 2.3 percent, significantly higher than the Environmental Protection Agency's current estimate of 1.4 percent.

油气业务占2.3%，远高于环境保护局目前估计的1.4%。

While the percentages seem small, methane is a potent greenhouse gas and the additional emissions would erase the climate advantages of burning natural gas instead of coalduring the period when methane's effects on the climate are most pronounced.

虽然百分比似乎很小，但甲烷是一种强大的温室气体，额外的排放会消除甲烷对气候的影响最明显的时期燃烧天然气而不是煤的气候优势。

Though half of methane vanishes in 8.3 years, EDF says it is still 84 times as powerful as carbon dioxide over 20 years.

虽然甲烷的一半在8.3年内消失了，但EDF表示，20多年来，甲烷的威力仍然是二氧化碳的84倍。

The EPA uses a broader time frame and says methane's global warming effect is 28 to 36 times that of carbon dioxide over the course of a century.

EPA使用更广泛的时间跨度，并表示甲烷的全球升温效应在这一世纪中是二氧化碳的28至36倍。

"Natural gas losses are a waste of a limited natural resource, increase global levels of surface ozone pollution, and significantly erode the potential climate benefits of natural gas use," the study's authors wrote.

该研究的作者写道：“天然气损失是一种有限自然资源的浪费，在全球范围内增加了臭氧污染的水平，并大大削弱了天然气使用的潜在气候惠益。

They added that the climate effects of emitting 13 million metric tons of methane over 20 years "roughly equals" the carbon dioxide emissions from all U.S. coal-fired power plants operating in 2015.

他们补充说，在20年间排放1,300万公吨甲烷的气候影响“大致相当于“美国2015年所有发电厂的二氧化碳排放量。

It would equal about 31 percent of the carbon dioxide emissions from U.S. coal plants over a 100-year time horizon.

它大约相当于美国煤厂100内时间跨度的二氧化碳排放量的31%。

"In the short term, the climate impacts of burning coal in a modern plant vs natural gas in a modern plant are similar as a result of the supply chain methane emissions," Fred Krupp, president of the Environmental Defense Fund, said in an email.

环境保护基金总裁Fred Krupp在一封电子邮件中说：“在短期内，在现代工厂焚烧煤对比天然气在现代工厂产生的气候影响与供应链甲烷的排放相似。”

But, he added, "over the long term the climate impacts of using gas to generate electricity will be significantly less than those of using coal even with high methane emissions."

但是，他补充道，“从长远来看，使用天然气发电的气候影响将远低于使用煤，即使会产生高甲烷的排放量。”

Moreover, he added, "if methane emissions were reduced, which they can be easily, it could deliver significant short term climate benefits as well."

此外，他还说，"如果减少甲烷的排放，这很容易，那么甲烷也能带来显著的短期气候惠益"。

The study, which relied largely on companies willing to cooperate, cautioned that its estimates could be too low. It said that the worst actors were most likely to opt out of taking part in the study.

该研究主要依赖于愿意合作的公司，因而被警告说，其估计可能太低，说最糟糕的行为体最有可能选择不参与这项研究。

In addition, the study has not updated measurements of local distribution systems, which could be emitting substantial volumes as well.

此外，这项研究没有更新当地配送系统的测量数据，这些系统也可能排放大量体积（的气体）。

The Science study said one possible explanation for the gap between its estimates and EPA's might be that EPA did not adequately count emissions in abnormal conditions.

科学研究说，对其估算值与环保局之间的差距，一个可能的解释是，环保局没有充分计算异常情况下的排放量。

The Science study used an extensive aerial infrared camera survey of about 8,000 production sites in seven U.S.

该研究利用了广泛的空中红外相机对7个美国约8000个生产地点进行调查。

oil and natural gas basins and found that about 4 percent of surveyed sites had one or more observable plumes, with two to seven times the methane emissions from average sites.

The study said that the industry could take steps to lower the level of methane emissions.

该研究表明，该行业可以采取步骤降低甲烷的排放水平。

It recommended that companies install less failure-prone systems, carry out on-site leak surveys, re-engineer individual components and processes, and deploy sensors at individual facilities and on towers, aircraft or satellites.

它建议各公司安装较少的失效易发生系统，进行现场泄漏调查，重新设计各个组件和工程，并在各个设施和塔楼、飞机或卫星上部署传感器。

"Scientists have uncovered a huge problem, but also an enormous opportunity," EDF chief scientist Steven Hamburg, a co-author of the study, said in a statement.

该研究的共同作者Steven Hamburg在一份声明中说：“科学家发现了巨大的问题，但也带来了巨大的机遇。

"Reducing methane emissions from the oil and gas sector is the fastest, most cost-effective way we have to slow the rate of warming today, even as the larger transition to lower-carbon energy continues."

“ 减少石油和天然气部门的甲烷排放是我们必须减缓今天的暖化速度的最迅速、最符合成本效益的方式 , 即使向低碳能源的更大过渡仍在 继续 。”

The study takes an important step in measuring methane leaks, especially from natural operations.

这项研究在测量甲烷泄漏, 特别是来自自然操作方面迈出了重要一步.

Last October, the International Energy Agency said "methane is a potent greenhouse gas and the uncertainty over the level of methane emitted to the atmosphere raises questions about the extent of the climate benefits that gas can bring."

去年10月，国际能源机构说，“甲烷是一种强大的温室气体，而对大气中排放的甲烷水平的不确定性使人们对天然气能够带来的气候惠益的范围提出疑问。”

It said, "One critical question is the extent to which methane emissions along the gas value chain negate the climate advantages of gas."

该报告指出，“一个关键问题是天然气价值链上甲烷的排放在多大程度上否定了天然气的气候优势。”

But the IEA also estimated that 40 to 50 percent of current methane emissions could be avoided at no net cost.

但国际能源机构还估计，目前40%至50%的甲烷排放量可以避免净成本。

"The environmental case for gas does not depend on beating the emissions performance of the most carbon-intensive fuel," the IEA said, "but in ensuring that its emission intensity is as low as practicable."

国际能源机构说：“天然气的环境情况并不取决于战胜碳密集型燃料的排放性能，而是取决于确保其排放强度尽可能低。