Hot Spots of Climate Extremes in the Future

Abstract

A Regional Extreme Climatic Change Index (RECCI), simultaneously considering the changes in intensity, frequency and interannual variability of three major extreme climatic variables (i.e., precipitation, temperature and wind speed), is constructed to represent regional changes of climate extremes in response to global warming. First, the daily outputs from 13 models in the Coupled Model Intercomparison Project phase 5 project in both historical and future simulations under the Representative Concentration Pathway 8.5 scenario are used to compute the extreme climatic indices. Second, the RECCI is computed on both annual and seasonal time scales during three periods (i.e., 2016–2035, 2046–2065 and 2080–2099) over 26 subregions. Finally, the spatiotemporal change of the RECCI is investigated, and then, the 26 subregions are classified into four categories for each period. The first category with the largest RECCI value is very sensitive to global warming, which is called hot spots of climate extremes. The results show that most hot spots are not time invariant on annual and seasonal time scales with some exceptions. On the annual time scale, the Amazon Basin is the only persistent hot spot in all three periods. For the seasonal time scale in March‐April‐May, the climate extremes in the Amazon Basin always display the strongest responsiveness to global warming, and the Eastern Africa is the only persistent hot spot in June‐July‐August in three periods. Similar results are also found for the other two seasons and periods. In addition, the change in extreme temperature is crucial over the East Asia with change in frequency prominent.

Zonally contrasting shifts of the tropical rain belt in response to climate change

“…These changes in the regional extratropical atmospheric heating induce an increase in the southward energy transport over the tropics of eastern Africa and Indian Ocean (and an northward shift of the EFE), and an increase in the northward energy transport over the tropical eastern Pacific – Atlantic sector (and a southward shift of the EFE), both of which are physically and statistically consistent with the revealed ITCZ response. Our results provide a single theoretical framework for simultaneously explaining anticipated future increases of drought stress in southeastern Africa and Madagascar, intensifying flooding in southern India 56 , and greater drought stress in Central America 38 – large hydrological hotspots of global change 88 , 89 that will have considerable impacts on food security and biodiversity.…”

Projected increase in compound dry and hot events over global land areas

“…At the global scale, several recent investigations based on historical records have demonstrated the variation in compound dry and hot events mainly in terms of their frequency or severity, and an increase was detected in most parts of the world (Hao et al ., 2013; Zscheischler and Seneviratne, 2017; Sarhadi et al ., 2018). In addition to extensive studies on future projections of droughts or heat‐related extremes under global warming (Dai, 2012; Diffenbaugh and Giorgi, 2012; Xu et al ., 2019), increased attention has also been paid to the variation in compound dry and hot events in the future based on climate model projections at different spatial scales (Zscheischler and Seneviratne, 2017; Sarhadi et al ., 2018; Zhou and Liu, 2018). For example, Zscheischler and Seneviratne (2017) assessed changes in the likelihood of compound dry and hot events in the future based on Coupled Model Intercomparison Project Phase 5 (CMIP5) simulations using the copula method and showed an increased likelihood of these events in most regions across the globe.…”

Pre-Columbian Fire Management Linked to Refractory Black Carbon Emissions in the Amazon

“…These factors can contribute to positive feedbacks that threaten to convert the Amazon from a net-carbon sink to a net-carbon source, further impacting the global carbon budget [87]. In addition, under increased CO 2 emission scenarios, climate model experiments demonstrate the Amazon Basin will likely experience substantial declines in regional-scale annual rainfall [88], coupled with increased occurrence of climate extremes [89]. Fire modeling of Amazon understory projects an increase in fire frequency and duration under increased carbon emission scenarios [90].…”