Half a degree more warming may cause up to 10x more intensification of droughts and floods

–The scenario with 0.5°C more warming showed significantly greater intensification. Disaster risks could be substantially reduced by reaching the 1.5°C target.

Extreme dry and wet events will increasingly co-occur, such as the switch from extreme drought to severe flooding we saw in California in the recent past

–More intense precipitation is predicted across much of North America and Eurasia, whereas more intense droughts are projected for the Mediterranean region

Madakumbura, et al. Event-to-event intensification of the hydrologic cycle from 1.5 °C to a 2 °C warmer worldScientific Reports, 2019; 9 (1) DOI: 10.1038/s41598-019-39936-2

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In 2015, to combat the urgent threats posed by climate change, most of the world’s countries came together to establish the Paris Agreement: an ambitious plan to prevent the global temperature from rising 2°C above pre-industrial levels, and to work to further limit that temperature rise to 1.5°C.

These seemingly small numbers can mask the staggering impact and complexity that shifts in global temperature represent. For example, increased global temperature will also intensify the hydrologic cycle, significantly changing the frequency and intensity of rainfall. Flooding, droughts, mudslides, and food and water insecurity are just some of the many hazards of the resulting changes in rainfall patterns.

…. Another key finding was that the most extreme intensification would be about 10 times greater than the average intensification. “Our results suggest that extreme dry and wet events will increasingly co-occur, such as the switch from extreme drought to severe flooding we saw in California in the recent past,” says lead author Gavin D. Madakumbura. “At least in terms of disaster mitigation and water security, there would be significant benefits to limiting global warming to 1.5°C to dampen the intensification of event-to-event variability.”