Global and regional impacts of climate change at different levels of global temperature increase

Abstract

The assessment of the impacts of climate change at different levels of global warming helps inform national and international policy discussion around mitigation targets. This paper provides consistent estimates of global and regional impacts and risks at increases in global mean temperature up to 5°C above pre-industrial levels, for over 30 indicators representing temperature extremes and heatwaves, hydrological change, floods and droughts and proxies for impacts on crop yields. At the global scale, all the impacts that could plausibly be either adverse or beneficial are adverse, and impacts and risks increase with temperature change. For example, the global average chance of a major heatwave increases from 5% in 1981-2010 to 28% at 1.5°C and 92% at 4°C, of an agricultural drought increases from 9 to 24% at 1.5°C and 61% at 4°C, and of the 50-year return period river flood increases from 2 to 2.4% at 1.5°C and 5.4% at 4°C. The chance of a damaging hot spell for maize increases from 5 to 50% at 4°C, whilst the chance for rice rises from 27 to 46%. There is considerable uncertainty around these central estimates, and impacts and risks vary between regions. Some impacts-for example heatwaves-increase rapidly as temperature increases, whilst others show more linear responses. The paper presents estimates of the risk of impacts exceeding specific targets and demonstrates that these estimates are sensitive to the thresholds used.

Projections of Future Climate Change in the Vu Gia Thu Bon River Basin, Vietnam by Using Statistical DownScaling Model (SDSM)

“…As a consequence, natural and human systems have to deal with a wide range of climate-related risks. Based on a comparison between 1.5 • C and 4 • C warming, it is evident that the global average chance of major heatwave, agricultural drought, and 50-year return period river flood is likely to rise from 28%-92%, 24%-61%, 2.4%-5.4%, respectively [2]. Furthermore, Arnell et al [3] utilized various indicators representing heat extremes, water resources, river and coastal flooding, droughts, agriculture, and energy use to estimate the potential impacts of climate change under different levels of climate forcings and socio-economic scenarios.…”

The global and regional impacts of climate change under representative concentration pathway forcings and shared socioeconomic pathway socioeconomic scenarios

“…Whilst other studies have developed relationships between level of forcing and impact (e.g. Schleussner et al 2016, Seneviratne et al 2016, Arnell et al 2016a, Arnell et al 2019, this is the first time that such relationships have been combined with probabilistic temperature projections to estimate impacts under different forcings.…”

“…The analysis develops on earlier work (Arnell et al 2013(Arnell et al , 2016b(Arnell et al , 2019, and uses more up-to-date climate pathways, climate models and socio-economic scenarios, probabilistic projections of global temperature change, and additional indicators that characterise a wider range of hazards and impacts. This paper presents summary charts of global and continental impacts, whilst more comprehensive regional tables and charts are presented in supplementary material is available online at stacks.iop.org/ERL/14/084046/ mmedia.…”

Climate Variability and Wheat Crop Yield in Pakistan: Analyzing Food Security Prospects in Selected Agro Climatic Zones

“…The effect of variations in temperature and rainfall depends on every region's geographical characteristics. Climate fluctuations are significant determinants of its yield, but soil existence will alter the effect of climate variability entirely differently from geographical position (Arnell et al, 2019). In the winter season, wheat has expanded and the cool weather sprouts the seeds at a better rate.…”