Summer is coming…
In the June 17, 2019 publication of the Carbon Brief website, there is an overview of Nature Climate Change's study "Setting and smashing extreme temperature records over the coming century". This study explores the frequency with which new temperature records are likely to be set in the future in each region of the world. It tells us that more than half of the planet could experience new temperature records every year by the end of the century if global warming is not slowed down. The graph below shows the percentage of people on the planet seeing new temperature records set at least one month per year between now and 2100, according to two scenarios: one with very high greenhouse gas emissions, RCP8.5, and the other where global warming is limited to less than 2°C, RCP2.6.
The percentage of the world surface area seeing new temperature records in RCP8.5 and RCP2.6 scenarios
Source: Carbon Brief, Power & Delage (2019)
It should be noted that for a scenario at less than 2°C, which is already an ambitious scenario in terms of climate mitigation, 30% of all countries would encounter at least 1 monthly temperature record per year until 2040. For RCP8.5 scenario, the results show that more than 50% of the planet could see a new temperature record set at least one month per year by 2040 and up to 58% by 2100.
It is known that the last four years have been the warmest on record with 2016 the warmest of all. If we put this information in perspective with the expected evolution of current temperatures, we can expect very high temperatures by 2040 and more particularly in the tropics, which are the vast majority of the poorest regions. More specifically, these new heat records could be set in two-thirds of the world's least developed countries under the high emission scenario. In addition, the researchers looked at the numerical increase in these temperatures and found that in any given year until 2100, just under a quarter of the planet can expect to see a new temperature record 0.5°C higher than its predecessor in the high emission scenario.
Although temperature estimation models have limitations, including their ability to project future averages rather than extremes, these results still reinforce the imperative need to reduce greenhouse gas emissions. Indeed, natural disasters and the threshold effects of extreme weather events can profoundly increase the disruptions caused by climate change.
Félix Fouret, Carbon/Climate Analyst
Source: Beyond Ratings, Carbon Brief, Nature Climate Change