The rapid expansion of natural gas development in the United States has been a double-edged sword. While natural gas supporters are quick to point out its economic benefits and green attributes—natural gas produces roughly half the carbon dioxide emissions of coal during combustion—this isn’t the whole story. Natural gas comes with environmental consequences, including risks to air and water quality.

一个风险是“fugitive methane emissions,”potent greenhouse gases that escape into the atmosphere throughout the natural gas development process. This methane—which is 25 times more potent than carbon dioxide over a 100-year timeframe—contributes to global warming and undercuts the climate advantage that cleaner-burning natural gas has over coal and diesel. (Learn more about fugitive methane emissions inour recent blog post）

Despite the controversy surrounding natural gas development, energy forecastssuggest天然气将留在这里。幸运的是，有几种途径可以限制与其发展相关的气候影响。必威官网是真的吗WRI刚刚发布了一张工作文件，Clearing the Air: Reducing Upstream Greenhouse Gas Emissions from U.S. Natural Gas Systems，概述了许多州和联邦政策以及行业的最佳实践，以降低逃亡的甲烷排放。我们发现，随着适量的减少，天然气确实从温室气体（GHG）排放量比煤炭和柴油提供了优势。

Reining in Fugitive Methane Emissions

尽管reports varyon the extent of the fugitive methane emission problem, recent studies estimate U.S. leakage rates in the range of 2 – 3 percent of total production, with some published estimates as high as 7 percent. To put that in perspective, at a 2 percent leakage rate,more than 6 million metric tonsof methane escape into the atmosphere in one year--an amount equivalent to the annual emissions of roughly 120 million cars. Our research shows that reducing the current methane leakage rate by two-thirds--i.e., down to 1 percent or less of total production--ensures that switching from diesel or coal to natural gas provides anet climate benefit在任何时间范围内。此外，我们发现我们可以通过现有的州和联邦政策以及广泛使用具有成本效益的技术来达到1％的目标。

Start with “Green Completions”

The U.S. Environmental Protection Agency (EPA) recently took significant steps toward addressing emissions from new gas development sites. The EPA’s New Source Performance Standards (NSPS), finalized in April 2012, aim to reduce volatile organic compounds (VOCs) and air toxics, but have the co-benefit of reducing fugitive methane. The rule requires “green completions” for all hydraulic fracturing operations, ensuring that methane emissions are no longer intentionally vented from shale gas wells. (The rule does not address methane accidentally leaked throughout the natural gas lifecycle).我们的分析发现该规则将到2015年将总上游甲烷排放量减少17％，到2035年将29％降低（参见下图中的金线）。

Apply 3 Technologies

EPA’s recent policy can get the United States closer to the 1 percent leakage target, but a lot of work remains to be done. Widespread implementation ofthree additional emissions-control technologies在新的和现有的井和设备上，可以极大地帮助您。使用柱塞升降机系统，将高流血气动设备的现有库存切换为低血压等效物，以及在加工厂和压缩机站使用甲烷泄漏检测和维修技术可以再减少30％，使整体泄漏率降低到超过1％（请参阅下图中的紫色线）。这些技术非常成本效益，在三年或更早的时间内为自己付款。

使用现有当局直接解决温室气体排放

为了满足和超过1％的泄漏目标，直接解决甲烷而不是依靠解决VOC或其他污染物的规则的共同利益，这将很重要逃亡甲烷排放的来源。Fortunately, many policy pathways exist at the state and federal levels that, with theappropriate level of ambition和combined with NSPS and policies that encourage use of the aforementioned technologies, can get us below the 1 percent target (see the green “Go Getter” scenario in the above infographic).

The federal Clean Air Act, for example, is an appropriate tool for setting national standards for pollutants,including GHGs like methane。EPA可以为甲烷和二氧化碳建立新的性能标准，以减少整个天然气供应链中这些有害污染物的新来源和现有来源。

Moving Forward with Emissions Reductions

Climate change is happening faster than scientists were predicting just a few years ago, and we know that methane emissions are partly responsible for fueling this warming. Cutting methane leakage from natural gas systems is a key step in meeting the United States’stated goal到2020年，其温室气体排放量降低了2005年的水平17％。

我们有技术，我们知道政策。现在，由行业和政府确保fugitive methane emissions保持尽可能低。