The emergence of cumulative climate risks
On Monday, November 19, the scientific journal Nature Climate Change published a study, carried out by about twenty international researchers, that can be described as both original and worrying. The study puts into perspective the cumulative risks caused by climate change by exposing each region of the world to a number of climate disasters of maximum intensity by 2095.
Based on the following 10 climatic hazards - Natural cover change, drought, warming, Heatwaves, storms, precipitation, floods, fires, sea level and ocean climate change - and by breaking down into 89 subheadings the six aspects crucial to human life - health, food, water, economy, infrastructure and security - the researchers concluded that humanity had already been affected by climate in 467 different forms. Based on this observation, which already demonstrates humanity's vulnerability to climate risk in the past, researchers are warning of the threat of the concomitant and combined occurrence of multiple climate risks.
Indeed, we can see on the maps above that when we compare a scenario where emissions continue to be as high as they are today with a scenario where greenhouse gas emissions are reduced to limit temperature increases to +2°C, we see once again an alarming difference. By 2100, the world's population will be exposed concurrently to the equivalent of the largest magnitude in one of these hazards if emissions are aggressively reduced, or three if they are not, with some tropical coastal areas facing up to six simultaneous hazards. In addition to the occurrence of events, the domino effect generated by our carbon emissions could increase the concomitance of the climate risks. For example, since this summer, California has faced extreme heat waves, forest fires and one of its longest droughts. This research is in line with the actual studies published on the physical risks of climate change and Nicholas Stern's first warnings on the cost of inaction versus action to further reduce carbon emissions.
If this scenario is confirmed in the coming decades, even if most countries at risk are in emerging countries, considering the cumulative risks of this study should also lead to a reassessment of the risks for northern countries. For example, in Italy or in Spain, we could pass from a value of one climate hazards concurrently if we act, to 3.2 if we don’t.
Félix Fouret, Carbon/Climate Analyst
Sources : Beyond Ratings, Nature Climate Change, Le Monde