Climate feedbacks from wetlands and permafrost thaw in a warming world (CLIFFTOP)

变暖的世界中湿地和永久冻土融化的气候反馈（CLIFFTOP）

• 批准号: NE/P015050/1
• 负责人: Garry Hayman
• 金额: $ 17万
• 依托单位: NERC CEH (Up to 30.11.2019)
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FP015050%2F1
• 关键词: Climate; feedbacks; wetlands; permafrost; thaw

Carbon dioxide and methane are the most important long-lived greenhouse gases causing global warming and climate change. These two gases, which are the major components of the global carbon cycle, are added to and removed from the atmosphere in a wide range of ways, from both natural and human activities. Wetlands are the largest natural source of methane and methane emissions from wetlands are expected to increase in a warming world. Further, in high northern latitudes, large amounts of carbon are stored in frozen soils or permafrost. The polar regions are warming faster than other parts of the Earth. As these soils warm causing the permafrost to thaw, the stored carbon can be converted by microbial activity over time and released to the atmosphere as carbon dioxide or methane, leading to further warming and hence a positive feedback. Combined with landscape changes, this may lead to the formation of new wetlands resulting in further emissions of methane.Wetlands and permafrost thaw are therefore important biogeochemical processes that need to be included in models of the Earth's climate. Through their inclusion, climate, or now Earth System, models will then account for the feedbacks that wetlands and permafrost thaw produce on the physical climate system (e.g., on future temperature changes). Following the international climate agreement in 2015 to limit future temperature rises to less than 1.5-2 degrees centigrade above pre-industrial levels, there is an urgent need to quantify this contribution of wetlands and permafrost thaw as this will constrain the accumulated emissions of greenhouse gases that can be released from human activities such as fossil fuel combustion if global temperatures are to be stabilised.In this study, we will use the UK community state-of-the-art land surface model, the Joint UK Land Environment Simulator (JULES) to model wetlands and permafrost thaw. We plan targeted development of the land-surface model to enhance its capability for considering wetlands, permafrost thaw, methane and carbon dioxide emissions in a more consistent and integrated manner. For this work, we will use this improved version of JULES with a simplified but robust climate emulator, IMOGEN. IMOGEN replicates the behaviour of a wide range of more complex and resource intensive climate and Earth System models that contributed to the latest climate change assessment of the IPCC.We will undertake model runs with the JULES-IMOGEN modelling system (a) to assess the impact of Arctic carbon releases that are not included in many climate models, (b) to quantify the corresponding climate feedbacks and the impact of these additional emissions on allowed human emissions for 1.5 or 2 degree C climate stabilisations. The research proposed will provide important evidence to support the commitments made in the Paris Agreement to 'strengthen the global response to the threat of climate change.... and to pursue efforts to limit the temperature increase to 1.5 degree C above pre-industrial levels'.The outputs of the work will include:* papers for publication in the scientific literature, which will be included in the special IPCC assessment of the IPCC* wetland methane emission datasets for current day and future conditions that will be of value for the atmospheric modelling communityThe project links to and will complement ongoing work at the Met Office, our project partner, for the UK government.

二氧化碳和甲烷是导致全球变暖和气候变化的最重要的长期温室气体。这两种气体是全球碳循环的主要组成部分，通过自然和人类活动以多种方式添加到大气中或从大气中去除。湿地是最大的甲烷天然来源，随着世界变暖，湿地的甲烷排放量预计将会增加。此外，在北方高纬度地区，大量碳储存在冻土或永久冻土中。极地地区的变暖速度比地球其他地区更快。当这些土壤变暖导致永久冻土融化时，储存的碳可以随着时间的推移被微生物活动转化，并以二氧化碳或甲烷的形式释放到大气中，导致进一步变暖，从而产生正反馈。与景观变化相结合，这可能会导致新湿地的形成，从而进一步排放甲烷。因此，湿地和永久冻土融化是重要的生物地球化学过程，需要纳入地球气候模型中。通过气候或现在的地球系统，模型将解释湿地和永久冻土融化对物理气候系统（例如，未来温度变化）产生的反馈。继 2015 年国际气候协议将未来气温上升限制在工业化前水平以上 1.5-2 摄氏度以内之后，迫切需要量化湿地和永久冻土融化的贡献，因为这将限制温室气体的累积排放如果要稳定全球气温，化石燃料燃烧等人类活动可能会释放这些污染物。在这项研究中，我们将使用英国社区最先进的地表模型，即英国联合土地环境模拟器 (JULES) 对湿地和永久冻土融化进行建模。我们计划有针对性地开发地表模型，以增强其以更加一致和综合的方式考虑湿地、多年冻土融化、甲烷和二氧化碳排放的能力。对于这项工作，我们将使用 JULES 的改进版本和简化但强大的气候模拟器 IMOGEN。 IMOGEN 复制了一系列更复杂和资源密集型气候和地球系统模型的行为，这些模型为 IPCC 的最新气候变化评估做出了贡献。我们将使用 JULES-IMOGEN 建模系统 (a) 进行模型运行，以评估影响许多气候模型中未包含的北极碳排放量，(b) 量化相应的气候反馈以及这些额外排放对允许人类排放量的影响，以实现 1.5 或 2 摄氏度的气候稳定。拟议的研究将为支持《巴黎协定》中的承诺提供重要证据，即“加强全球对气候变化威胁的应对……并努力将气温上升限制在比工业化前水平高1.5摄氏度的范围内” '.这项工作的成果将包括：* 在科学文献中发表的论文，这些论文将纳入 IPCC 对当前和未来条件的湿地甲烷排放数据集的特别评估中，这些数据对大气具有价值模特社区项目与我们的项目合作伙伴英国政府英国气象局正在进行的工作有联系，并将对其进行补充。

项目成果

Carbon budgets for 1.5 and 2 °C targets lowered by natural wetland and permafrost feedbacks

自然湿地和永久冻土反馈降低了 1.5 和 2°C 目标的碳预算

• DOI: http://dx.10.1038/s41561-018-0174-9
• 发表时间: 2018
• 期刊: Nature Geoscience
• 影响因子: 18.3
• 作者: Comyn

Significant feedbacks of wetland methane release on climate change and the causes of their uncertainty

湿地甲烷释放对气候变化的显着反馈及其不确定性原因

• 发表时间: 2019
• 期刊: Environmental Research Letters
• 影响因子: 6.7
• 作者: Gedney N

Land-use emissions play a critical role in land-based mitigation for Paris climate targets.

土地使用排放在巴黎气候目标的土地缓解中发挥着关键作用。

• DOI: http://dx.10.1038/s41467-018-05340-z
• 发表时间: 2018
• 期刊: Nature communications
• 影响因子: 16.6
• 作者: Harper AB

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

Flexible parameter-sparse global temperature time profiles that stabilise at 1.5 and 2.0 °C

灵活的参数稀疏全局温度时间曲线，稳定在 1.5 和 2.0 °C

• DOI: http://dx.10.5194/esd-8-617-2017
• 发表时间: 2017
• 期刊: Earth System Dynamics
• 影响因子: 7.3
• 作者: Huntingford C