Abstract. Human-induced climate change is increasing the incidence of fire events and associated impacts on livelihood, biodiversity, and nature across the world. Understanding current and projected fire activity together with its impacts on ecosystems is crucial to evaluate future risks and take actions to prevent such devastating events. Here we focus on fire weather, as a key driver of fire activity. Fire weather products that have global homogenous distribution in time and space provide many advantages to advance fire science and evaluate future risks. Therefore, in this study we calculate the Canadian Fire Weather Index (FWI) with all available simulations of the 6th phase of the Coupled Model Intercomparison Project (CMIP6). The algorithm used here assembles improvements from several packages for the calculation of the FWI. A sensitivity analysis of the default versus the improved version shows significant differences in final FWI. With the improved version, we calculate the FWI using average relative humidity in one case and minimum relative humidity in another case. We provide the data for both cases, while recommending the one with average relative humidity for studies requiring large ensembles and the one with minimum relative humidity for studies focused on actual FWI values. The following four annual indicators: (i) maximum value of the FWI (fwixx), (ii) number of days with extreme fire weather (fwixd), (iii) length of the fire season (fwils), and (iv) seasonal average of the FWI (fwisa) are made available and illustrated here. We find that at a global warming level of 3 °C, the mean fire weather would on average double in duration and intensity, while associated 1-in-10-year events would triple in duration and increase by half in intensity. Ultimately, this new fire weather dataset provides a large ensemble of simulations to understand the potential impacts of climate change spanning a range of shared socioeconomic narratives with their radiative forcing trajectories. The produced full global dataset is a freely available resource at https://doi.org/10.3929/ethz-b-000583391 for fire danger studies and beyond, which highlights the need to reduce greenhouse gas emissions for reducing fire impacts.

中文翻译：

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1850-2100年CMIP6历史和SSP预估下的火灾天气指数数据

摘要。人为引起的气候变化正在增加火灾事件的发生率以及对全世界生计、生物多样性和自然的相关影响。了解当前和预计的火灾活动及其对生态系统的影响对于评估未来风险和采取行动防止此类破坏性事件至关重要。在这里，我们关注火灾天气，它是火灾活动的主要驱动因素。在时间和空间上具有全球均匀分布的火灾天气产品为推进火灾科学和评估未来风险提供了许多优势。因此，在本研究中，我们使用耦合模型比对项目 (CMIP6) 第 6 阶段的所有可用模拟来计算加拿大火灾天气指数 (FWI)。此处使用的算法汇集了几个用于计算 FWI 的包的改进。默认版本与改进版本的敏感性分析显示最终 FWI 存在显着差异。在改进版本中，我们在一种情况下使用平均相对湿度计算 FWI，在另一种情况下使用最小相对湿度。我们提供这两种情况的数据，同时为需要大型集合的研究推荐具有平均相对湿度的数据，为关注实际 FWI 值的研究推荐具有最小相对湿度的数据。以下四个年度指标：（i）FWI最大值（fwixx），（ii）极端火灾天气天数（同时为需要大型合奏的研究推荐具有平均相对湿度的一种，为侧重于实际 FWI 值的研究推荐具有最小相对湿度的一种。以下四个年度指标：（i）FWI最大值（fwixx），（ii）极端火灾天气天数（同时为需要大型合奏的研究推荐具有平均相对湿度的一种，为侧重于实际 FWI 值的研究推荐具有最小相对湿度的一种。以下四个年度指标：（i）FWI最大值（fwixx），（ii）极端火灾天气天数（fwixd），（iii）火灾季节的长度（fwils），和（iv）FWI的季节性平均值（fwisa) 在此处提供并进行了说明。我们发现，在 3 °C 的全球变暖水平下，平均火灾天气的持续时间和强度平均会翻一番，而相关的 10 年一遇事件的持续时间会增加两倍，强度会增加一半。最终，这个新的火灾天气数据集提供了大量模拟，以了解气候变化的潜在影响，涵盖一系列共享的社会经济叙述及其辐射强迫轨迹。生成的完整全球数据集是 https://doi.org/10.3929/ethz-b-000583391 上的免费资源，用于火灾危险研究及其他，它强调了减少温室气体排放以减少火灾影响的必要性。