作为美国居民,EPA是最好的开始想知道关于大气污染物排放清单的或污染物前体影响国家环境空气质量标准(例如可吸入颗粒物、一氧化碳、二氧化硫、铅、氮氧化物、挥发性有机化合物)。EPA编译的所有标准污染物综合排放清单中可用的县级国家排放清单(每三年一次编译)。你可以看到在http://www.epa.gov/air/emissions/where.htm县的总结。对大气污染的影响,重要的是要考虑到的一生说污染物在大气中为了把他们的环境影响。例如,空气污染物覆盖的国家环境空气质量标准直接定期健康影响当高浓度吸入。动物和植物都是由这些刺激性不利影响,有时有毒化学物质,但这些污染物也无功,不大气中持续太久,除非他们不断补充(如日常交通)。空气质量也影响临界氮负荷可能对生态系统和酸雨的生产。如果你感兴趣的温室气体(如甲烷、二氧化碳、氟氯化碳、一氧化二氮),EPA有一个单独的网站对于那些排放,因为他们不属于同一监管框架的http://www.epa.gov/climatechange/ghgemissions/。温室气体一般不会造成不良的健康影响植物或动物在陆地上。然而,他们有长期的辐射影响(如温室效应),因为他们在大气中停留多年和陷阱红外线。 These long-term radiative effects are what can change climate and consequently land cover. Furthermore, most of the excess carbon is absorbed by the ocean, which creates carbonic acid. Increased acidity of the ocean causes severe problems for marine ecosystems. The EPA states that in 2012 the CO2 equivalent GHG emissions for the USA by sector was: > Electricity production (32% of 2012 greenhouse gas emissions) - Electricity production generates the largest share of greenhouse gas emissions. Over 70% of our electricity comes from burning fossil fuels, mostly coal and natural gas. > > Transportation (28% of 2012 greenhouse gas emissions) - Greenhouse gas emissions from transportation primarily come from burning fossil fuel for our cars, trucks, ships, trains, and planes. Over 90% of the fuel used for transportation is petroleum based, which includes gasoline and diesel. > > Industry (20% of 2012 greenhouse gas emissions) - Greenhouse gas emissions from industry primarily come from burning fossil fuels for energy as well as greenhouse gas emissions from certain chemical reactions necessary to produce goods from raw materials. > > Commercial and Residential (10% of 2012 greenhouse gas emissions) - Greenhouse gas emissions from businesses and homes arise primarily from fossil fuels burned for heat, the use of certain products that contain greenhouse gases, and the handling of waste. > > Agriculture (10% of 2012 greenhouse gas emissions) - Greenhouse gas emissions from agriculture come from livestock such as cows, agricultural soils, and rice production. > > Land Use and Forestry (offset of 15% of 2012 greenhouse gas emissions) - Land areas can act as a sink (absorbing CO2 from the atmosphere) or a source of greenhouse gas emissions. In the United States, since 1990, managed forests and other lands have absorbed more CO2 from the atmosphere than they emit. If we consider GHGs on a global level (see Global Carbon Project http://www.globalcarbonproject.org/carbonbudget/index.htm ) we can see how each sector has impacted the atmospheric concentration of CO2 over the past 143 yrs. ![enter image description here][2] [2]: http://i.stack.imgur.com/S0OtF.png