Atmospheric Methane concentrations since 1984

This dataset shows the atmospheric methane concentrations since 1984. Data source: Data from NOAA, measured from a global network of air sampling sites. Methane (CH4) is a powerful greenhouse gas, and is the second-largest contributor to climate warming after carbon dioxide (CO2). A molecule of methane traps more heat than a molecule of CO2, but methane has a relatively short lifespan of 7 to 12 years in the atmosphere, while CO2can persistfor hundreds of years or more.Methane comes from both natural sources and human activities. An estimated 60% of today’s methane emissions are the result of human activities. The largest sources of methane are agriculture, fossil fuels, and decomposition of landfill waste. Natural processes account for 40% of methane emissions, with wetlands being the largest natural source. The concentration of methane in the atmosphere has more than doubled over the past 200 years. Scientists estimate that this increase is responsible for 20 to 30% of climate warming since the Industrial Revolution (which began in 1750).Although it’s relatively simple to measure the amount of methane in the atmosphere, it’s harder to pinpoint where it’s coming from. NASA scientists are using several methods to track methane emissions.One tool that NASA uses is the Airborne Visible InfraRed Imaging Spectrometer - Next Generation, or AVIRIS-NG. This instrument, which gets mounted onto research planes, measures light that is reflected off Earth’s surface. Methane absorbs some of this reflected light. By measuring the exact wavelengths of light that are absorbed, the AVIRIS-NG instrument can determine the amount of greenhouse gases present.NASA added the Earth Surface Mineral Dust Source Investigation (EMIT) instrument to the International Space Station in 2022. Though built principally to study dust storms and sources, researchers found that it could also detect large methane sources, known as “super-emitters.”These aircraft and satellite instruments are finding methane rising from oil and gas production, pipelines, refineries, landfills, and animal agriculture. In some cases, these measurements have led to leaks being fixed, including suburban gas leaks and faulty equipment in oil and gas fields.The Arctic is a source of natural methane from wetlands, lakes, and thawing permafrost. Although a warming climate could change these emissions, scientists do not yet think it will drive a major increase. To this end, NASA’s Arctic Boreal and Vulnerability Experiment, or ABoVE, has been measuring methane coming from natural sources like thawing permafrost in Alaska and Canada.Data Notes and SourcesNOAA’s methane data comes from a globally-distributed network of air sampling sites. https://gml.noaa.gov/ccgg/trends_ch4/Ice core data are from Law Dome (Antarctica) and Summit (Greenland) ice cores, from Etheridge, D.M., L.P. Steele, R.J. Francey, and R.L. Langenfelds, Atmospheric methane between 1000 AD and present: Evidence of anthropogenic emissions and climatic variability. Journal of Geophysical Research, 103, D13, 15,979-15,993, 1998.Data archived at the Carbon Dioxide Information Analysis Centerhttps://cdiac.ess-dive.lbl.gov/trends/atm_meth/lawdome_meth.htm

本数据集展示了自1984年以来的大气甲烷浓度。数据来源：美国国家海洋和大气管理局（NOAA）提供的数据，来自全球空气采样站网络。甲烷（CH4）是一种强效的温室气体，在二氧化碳（CO2）之后，是导致气候变暖的第二大贡献者。一个甲烷分子比一个二氧化碳分子更能吸收热量，但甲烷在大气中的寿命相对较短，为7至12年，而二氧化碳可以持续数百年或更长时间。甲烷的来源既包括自然因素，也包括人类活动。据估计，目前60%的甲烷排放是由人类活动造成的。甲烷的主要来源包括农业、化石燃料和填埋场垃圾的分解。自然过程导致了40%的甲烷排放，其中湿地是最大的自然来源。在过去200年间，大气中甲烷的浓度已增加了一倍以上。科学家们估计，这种增加是工业革命（始于1750年）以来20至30%的气候变暖的原因。尽管测量大气中甲烷的含量相对简单，但确定其来源则较为困难。美国国家航空航天局（NASA）科学家正在采用多种方法追踪甲烷排放。NASA使用的工具之一是航空可见光红外成像光谱仪——下一代（AVIRIS-NG），该仪器被安装于研究飞机上，用于测量反射自地球表面的光线。甲烷吸收部分反射光。通过测量被吸收的光的确切波长，AVIRIS-NG仪器可以确定温室气体的含量。NASA于2022年在国际空间站上增加了地球表面矿物尘埃源调查（EMIT）仪器。虽然该仪器主要用以研究沙尘暴及其来源，但研究人员发现它还可以检测到被称为“超级排放者”的大型甲烷来源。这些飞机和卫星仪器正在发现来自石油和天然气生产、输油管道、炼油厂、填埋场和动物农业的甲烷排放。在某些情况下，这些测量结果导致了泄漏的修复，包括郊区的天然气泄漏和油气田中的设备故障。北极地区是湿地、湖泊和融化的永久冻土的自然甲烷来源。尽管气候变暖可能会改变这些排放，但科学家们并不认为它将导致重大的增加。为此，NASA的北极 boreal 和脆弱性实验（ABoVE）正在测量来自阿拉斯加和加拿大融化的永久冻土等自然来源的甲烷。数据说明和来源：NOAA的甲烷数据来自全球分布的空气采样站网络。https://gml.noaa.gov/ccgg/trends_ch4/冰芯数据来自南极洲的拉伍德冰盖和格陵兰岛的顶峰冰芯，由Etheridge, D.M.，L.P. Steele，R.J. Francey，和R.L. Langenfelds在1998年的《地球物理研究》期刊上发表的《公元1000年至现在的大气甲烷：人为排放和气候变率的证据》一文中提供。数据存档在二氧化碳信息分析中心。https://cdiac.ess-dive.lbl.gov/trends/atm_meth/lawdome_meth.htm