The Global Methane Budget

全球甲烷预算

• 批准号: NE/N015746/2
• 负责人: Garry Hayman
• 金额: $ 3.07万
• 依托单位: UK CENTRE FOR ECOLOGY & HYDROLOGY
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FN015746%2F2
• 关键词: Global; Methane; Budget

Methane is the second most important greenhouse gas contributing to human-induced global warming. Atmospheric methane concentrations have increased sharply since 2007, for reasons that are not fully understood, resulting in ever-increasing uncertainty for future climate projections. The overall increase since 2007 is comparable to the largest growth events over the past 1000 years. The recent rises have occurred in the tropics and southern hemisphere, with the sharpest year-on-year increase thus far occurring in 2014. Strong growth continues in 2015. Carbon isotopic evidence suggests that the increase is due to sources that are predominantly biogenic in origin, with changes in the anthropogenic sources from fossil carbon and burning (e.g., natural gas leakage, fracking and so on) playing a minor role. This, taken with the tropical locus on growth, suggests that the increase has primarily been driven by meteorological change (e.g., temperature, rainfall). Moreover, the global methane budget is not well described. "Bottom-up" estimates, made by aggregating inventories of emissions (e.g. from gas leaks, fires, landfills, cows, etc) or from process models (e.g., wetlands) balanced with known loss processes, are significantly different from '"top-down" budgets assessed by direct measurement of methane in the atmosphere. Why this discrepancy occurs is not understood.The project has four components:1. Better Observations are needed to derive estimates of emissions. The project will support a UK observation network for methane and its isotopes. Continuous stations will be at Kjolnes (Norway), Weybourne, Jersey, NERC ship RRS JC Ross, Cape Verde, Ascension, Falklands, Halley Bay, Hong Kong, with partner stations in Canada, Spitsbergen, Bolivia, S. Africa, India, Rwanda and Malaysia. Flask or bag sampling (for methane, 13C and D/H isotopes) will also be undertaken at these stations and at a number of continental stations in S. America, Africa and S, SE and E Asia, with offline analysis in the UK. A D/H measurement facility will be set up. The UK FAAM aircraft will carry out flights across the Atlantic tropics, from Azores to Cape Verde to Ascension.2. Process Studies will address the largest information gaps in the global budget. Tropical emission fluxes and isotopic signatures are not well constrained. Field campaigns will be undertaken in tropical wetlands in Amazonia, Africa, India and SE Asia, and C4 savanna biomass burn regions. Poorly understood anthropogenic sources will be studied in Kuwait and S, SE and E Asia. Characteristic isotopic signatures of regional emissions will be determined, to support global and regional modelling. Land surface modelling and satellite studies will study emissions and responses to change in temperature and precipitation. Major sink processes will be investigated in the tropical atmosphere, with vertically and latitudinally resolved OH and Cl budget studies by the FAAM aircraft, and quantification of tropical uptake by soils.3. Atmospheric modelling will be used to derive regional and global fluxes, apportioned by source type and geography using integrated in situ and remote sensing observing systems. We will carry out regional trajectory studies using models like NAME to assess regional emissions. Global modelling using 3D models will test synthetic estimates of the methane mole fraction and isotopic record. Global inverse modelling for mole fraction, 13C and D/H will be used to estimate fluxes by geographic source and source type, including a comprehensive assessment of the uncertainties that remain once all available observations have been used.4. Integrative studies will use the results from the project to test top-down and bottom-up emission estimates, and evaluate the responses of the global methane budget to projections of climate change.The project will deliver a state of the art UK greenhouse gas monitoring network and reduced uncertainty of the global methane budget.

甲烷是导致人类引起的全球变暖的第二大温室气体。自 2007 年以来，大气中的甲烷浓度急剧增加，其原因尚不完全清楚，导致未来气候预测的不确定性不断增加。 2007 年以来的总体增长可与过去 1000 年来最大的增长事件相媲美。最近的上升发生在热带地区和南半球，迄今为止最大幅度的同比增长发生在 2014 年。2015 年继续强劲增长。碳同位素证据表明，碳同位素的增长主要是由于生物来源造成的。 ，来自化石碳和燃烧的人为来源的变化（例如天然气泄漏、水力压裂等）发挥了次要作用。与热带地区的增长情况相结合，表明增长主要是由气象变化（例如温度、降雨量）驱动的。此外，全球甲烷预算也没有得到很好的描述。 “自下而上”的估计是通过汇总排放清单（例如气体泄漏、火灾、垃圾填埋场、奶牛等）或根据与已知损失过程平衡的过程模型（例如湿地）进行的，与“自上而下”的估计有显着不同。通过直接测量大气中的甲烷来评估预算。为什么会出现这种差异尚不清楚。该项目有四个组成部分：1。需要更好的观测来得出排放量估计值。该项目将支持英国甲烷及其同位素观测网络。连续站点将位于 Kjolnes（挪威）、韦伯恩、泽西岛、NERC 船舶 RRS JC Ross、佛得角、阿森松岛、福克兰群岛、哈雷湾、香港，合作站点位于加拿大、斯匹次卑尔根岛、玻利维亚、南非、印度、卢旺达和马来西亚。这些站以及南美、非洲、南亚、东南亚和东亚的一些大陆站也将进行烧瓶或袋采样（甲烷、13C和D/H同位素），并在英国进行离线分析。将设立 D/H 测量设施。英国 FAAM 飞机将执行横跨大西洋热带地区的航班，从亚速尔群岛到佛得角再到阿森松岛。2。过程研究将解决全球预算中最大的信息缺口。热带排放通量和同位素特征没有得到很好的限制。实地活动将在亚马逊流域、非洲、印度和东南亚的热带湿地以及 C4 稀树草原生物质燃烧地区开展。将在科威特、南亚、东南亚和东亚研究人们知之甚少的人为来源。将确定区域排放的特征同位素特征，以支持全球和区域建模。陆地表面模型和卫星研究将研究排放以及对温度和降水变化的响应。将通过 FAAM 飞机进行垂直和纬度解析的 OH 和 Cl 预算研究，以及土壤对热带吸收的量化，对热带大气中的主要汇过程进行研究。3．大气建模将用于推导区域和全球通量，并使用集成的现场和遥感观测系统按源类型和地理位置进行分配。我们将使用 NAME 等模型进行区域轨迹研究，以评估区域排放量。使用 3D 模型的全局建模将测试甲烷摩尔分数和同位素记录的综合估计。摩尔分数、13C 和 D/H 的全局反演模型将用于按地理源和源类型估计通量，包括对使用所有可用观测值后仍然存在的不确定性进行综合评估。4。综合研究将利用该项目的结果来测试自上而下和自下而上的排放估算，并评估全球甲烷预算对气候变化预测的反应。该项目将提供最先进的英国温室气体监测网络并减少了全球甲烷预算的不确定性。

项目成果

Rising methane: is there a methane emergency?

甲烷上升：是否存在甲烷紧急情况？

• DOI: http://dx.10.1098/rsta.2021.0334
• 发表时间: 2022
• 期刊: Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
• 作者: Nisbet EG

Rising methane: is warming feeding warming?

甲烷上升：变暖正在导致变暖吗？

• DOI: http://dx.10.1098/rsta.2020.0459
• 发表时间: 2021
• 期刊: Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
• 作者: Nisbet EG

Regional variation in the effectiveness of methane-based and land-based climate mitigation options

基于甲烷和基于陆地的气候缓解方案有效性的区域差异

• DOI: http://dx.10.5194/esd-12-513-2021
• 发表时间: 2021
• 期刊: Earth System Dynamics
• 影响因子: 7.3
• 作者: Hayman G

Phenology is the dominant control of methane emissions in a tropical non-forested wetland.

物候是热带非森林湿地甲烷排放的主要控制因素。

• DOI: http://dx.10.1038/s41467-021-27786-4
• 发表时间: 2022
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Helfter C

Methane flux measurements along a floodplain soil moisture gradient in the Okavango Delta, Botswana.

博茨瓦纳奥卡万戈三角洲漫滩土壤湿度梯度的甲烷通量测量。

• DOI: http://dx.10.1098/rsta.2020.0448
• 发表时间: 2021
• 期刊: Philosophical transactions. Series A, Mathematical, physical, and engineering sciences
• 作者: Gondwe MJ