Climate change impacts on global wildfire ignitions by lightning and the safe management of landscape fuels

气候变化对闪电引发的全球野火和景观燃料安全管理的影响

• 批准号: NE/V01417X/1
• 负责人: Matthew Jones
• 金额: $ 83.73万
• 依托单位: University of East Anglia
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FV01417X%2F1
• 关键词: Climate; change; impacts; global; wildfire

2020 will be remembered not only for Covid-19, but also for its devastating wildfires. The year began with the Australian bushfires, which caused 34 deaths and over US$70 billion of damages. The wildfires that are currently burning across the Western US look set to be the costliest in US history, with over 30 people already killed directly. The wildfires of 2020 join a growing list of extreme wildfires seen in Mediterranean Europe, North America, Australia, Siberia and the Arctic in the past decade. Wildfires are strongly tied to climatic droughts, which enhance the flammability of vegetation. As drought frequency is projected to rise in future, there are serious concerns that the fires seen in recent years are a glimpse into a more fire-prone future. Lightning strikes are the dominant cause of wildfire in many regions and, for example, ignited many of the recent Australian and US fire complexes.It is critical that we understand the drivers of wildfire, build capacity to predict their future likelihood, and take steps to mitigate their impacts. Our current understanding of fires at the global scale is built around satellite observations. However, these observations are insufficient to disentangle the diverse drivers of fire; they see only patterns. Satellite observations provide a mixed signal of many different types of fire, including wildfires but also a range of fires under human control (e.g. agricultural fires and deforestation fires), meaning that observations of wildfire are 'contaminated' with other fire types. Critically, this obscures trends in wildfire activity and compromises our understanding of climate impacts on wildfire activity. The proposed project will create the first global capacity to isolate lightning-ignited wildfires from satellite observations. It will use new observations of lightning strikes from ground- and satellite-based lightning sensors to 'decontaminate' satellite observations and introduce a global dataset of lightning-ignited wildfire activity. The new dataset will be used to make key advances in the understanding of wildfires and their relationship with climate. The project will assess how wildfire activity has changed in recent decades, and it will specifically determine the climatic conditions under which lightning fires occur. This new understanding of fire drivers will be built into the UK Earth System model and used to predict the impact of climate change on wildfire activity in the future century. The new capacity to observe wildfires will also enable a major advance in the estimation of deforestation fire emissions, specifically in Amazonia which accounts around 40% of global emissions due to land use change. Deforestation fire emissions contribute to an increase in atmospheric concentrations of CO2 and contribute to climate change. However, emissions from Amazonian deforestation fires are known to be overestimated because emissions from lightning-ignited wildfires are undesirably included in the estimates. The new record of lightning-ignited wildfires developed in this study will be used to correct the emissions estimates and discount wildfires that occur as part of a natural disturbance-recovery cycle in the region.Finally, this project will evaluate our future capacity to manage the threats of wildfires in a changing climate using conventional approaches to forest fuel management. It is common in some regions (e.g. Australia and the western US) to manage forest fuel stocks by burning off the most flammable fuels on the forest floor. However, this practice can only be applied safely during cool, moist, wind-free weather that occur in an annual 'window' of opportunity. It is feared that this window will narrow in future due to climate change. In this project, climate model outputs will be used to predict change in the window to 2100, informing forest management agencies of their future challenges and resource needs.

2020 年不仅会因 Covid-19 被铭记，还会因其毁灭性的野火而被铭记。今年年初，澳大利亚发生丛林大火，造成 34 人死亡，损失超过 700 亿美元。目前正在美国西部燃烧的山火看来将是美国历史上损失最惨重的一次，已造成 30 多人直接死亡。过去十年，地中海欧洲、北美、澳大利亚、西伯利亚和北极地区发生了越来越多的极端山火，而 2020 年的山火又加入其中。野火与气候干旱密切相关，气候干旱增加了植被的易燃性。由于预计未来干旱频率将会上升，人们严重担心近年来发生的火灾预示着未来更加容易发生火灾。雷击是许多地区野火的主要原因，例如，雷击引发了最近澳大利亚和美国发生的许多火灾。至关重要的是，我们了解野火的驱动因素，建立预测其未来可能性的能力，并采取措施来扑灭野火。减轻其影响。我们目前对全球范围内火灾的了解是建立在卫星观测的基础上的。然而，这些观察结果不足以理清火灾的不同驱动因素；他们只看到模式。卫星观测提供了许多不同类型火灾的混合信号，包括野火，但也包括人类控制下的一系列火灾（例如农业火灾和森林砍伐火灾），这意味着对野火的观测受到其他火灾类型的“污染”。至关重要的是，这掩盖了野火活动的趋势，并损害了我们对气候对野火活动影响的理解。拟议的项目将建立全球第一个将闪电引发的野火与卫星观测隔离的能力。它将利用地面和卫星闪电传感器对雷击的新观测结果来“净化”卫星观测结果，并引入闪电引发野火活动的全球数据集。新的数据集将用于在了解野火及其与气候的关系方面取得重大进展。该项目将评估近几十年来野火活动的变化，并将具体确定闪电火灾发生的气候条件。这种对火灾驱动因素的新认识将被纳入英国地球系统模型中，并用于预测气候变化对未来世纪野火活动的影响。观察野火的新能力也将使森林砍伐火灾排放的估算取得重大进展，特别是在亚马逊地区，该地区因土地用途变化而产生的排放量约占全球排放量的 40%。毁林火灾排放导致大气中二氧化碳浓度增加，并导致气候变化。然而，众所周知，亚马逊森林砍伐火灾的排放量被高估了，因为闪电引发的野火的排放量被不合需要地包含在估计中。本研究中开发的闪电引发野火的新记录将用于修正排放估计并减少该地区自然扰动-恢复周期中发生的野火。最后，该项目将评估我们未来管理森林火灾的能力。使用传统的森林燃料管理方法应对气候变化中的野火威胁。在某些地区（例如澳大利亚和美国西部），通过燃烧森林地面上最易燃的燃料来管理森林燃料库存是很常见的。然而，这种做法只能在每年“机会之窗”出现的凉爽、潮湿、无风的天气下安全地应用。人们担心，由于气候变化，这个窗口将来会缩小。在该项目中，气候模型输出将用于预测 2100 年窗口内的变化，向森林管理机构通报其未来的挑战和资源需求。

项目成果

Pyrogenic carbon decomposition critical to resolving fire's role in the Earth system

热解碳分解对于解决火灾在地球系统中的作用至关重要

• DOI: http://dx.10.1038/s41561-021-00892-0
• 发表时间: 2022
• 期刊: Nature Geoscience
• 影响因子: 18.3
• 作者: Bowring S

Global Carbon Budget 2021

2021 年全球碳预算

• DOI: http://dx.10.5194/essd-14-1917-2022
• 发表时间: 2022
• 期刊: Earth System Science Data
• 影响因子: 11.4
• 作者: Friedlingstein P

Extratropical forests increasingly at risk due to lightning fires

温带森林因闪电火灾而面临的风险日益增加

• DOI: 10.1038/s41561-023-01322-z
• 发表时间: 2023-11-09
• 期刊: Nature Geoscience
• 影响因子: 18.3
• 作者: Thomas A. J. Janssen;Matthew W. Jones;D. Finney;G. R. van der Werf;Dave van Wees;Wenxuan Xu;S. Veraverbeke
• 通讯作者: S. Veraverbeke

Definitions and methods to estimate regional land carbon fluxes for the second phase of the REgional Carbon Cycle Assessment and Processes Project (RECCAP-2)

• DOI: 10.5194/gmd-2020-259
• 发表时间: 2020-09-25
• 期刊: Geoscientific Model Development
• 影响因子: 5.1
• 作者: P. Ciais;A. Bastos;F. Chevallier;R. Lauerwald;B. Poulter;J. Canadell;G. Hugelius;R. B. Jackson;Atul K. Jain;M. Jones;Masayuki Kondo;Ingrid T. Luijkx;P. Patra;W. Peters;J. Pongratz;A. Petrescu;S. Piao;Chunjing Qiu;C. von R;ow;ow;P. Régnier;M. Saunois;R. Scholes;A. Shvidenko;H. Tian;Hui Yang;Xuhui Wang;B. Zheng
• 通讯作者: B. Zheng

The black carbon cycle and its role in the Earth system

• DOI: 10.1038/s43017-022-00316-6
• 发表时间: 2022-07-07
• 期刊: Nature Reviews Earth & Environment
• 影响因子: 42.1
• 作者: Alysha I. Coppola;S. Wagner;S. Lennartz;M. Seidel;N. Ward;T. Dittmar;C. Santín;Matthew W. Jones
• 通讯作者: Matthew W. Jones