Floods, droughts, fires, heat waves and cold waves are set to become increasingly common due to climate change. And more and more people will pay the price. A new study by the Norwegian Center for International Climate Research (Cicero), published in Nature Geoscience, predicts that in the next 20 years extreme weather events could become very common in a large portion of our planet, where 70 percent of the entire human population currently lives.
According to calculations by Norwegian scientists, the speed with which extreme temperatures and precipitation will spread depends heavily on the measures that will be implemented to limit greenhouse gas emissions. In the worst-case scenario, the so-called business-as-usual scenario in which no significant progress is made in combating CO2 emissions, the entire tropical and subtropical belt of the Earth will be affected by frequent extreme weather events within the next 20 years.
A huge area inhabited by 70 percent of our species, and which includes the Mediterranean (and therefore Italy), one of the regions where the climate is destined to change most rapidly, and where there is also less hope of being able to intervene to avoid it. Looking at climate scenarios in which emissions are actually reduced as foreseen by the Paris Agreement, the portion of the planet affected by frequent extreme weather events in the next 20 years would in fact be destined to reduce, but not disappear: according to simulations carried out by Norwegian researchers, in areas such as the Mediterranean the effects of climate change would now be unstoppable.
Best case scenario
Even in the best-case scenario, over the next 20 years, 20 percent of the human population will be exposed to frequent extreme weather events, and their effects on human health and the economy.
“Our societies are particularly vulnerable to a high rate of change in climate extremes, especially if they occur simultaneously on multiple sides,” the authors of the research explain. “Precipitation extremes can cause flooding and damage settlements, infrastructure, crops and ecosystems, increasing erosion and reducing the quality of water resources. Heat waves, on the other hand, can cause thermal stress, increased mortality of people and livestock, put ecosystems to the test, reduce agricultural productivity, create criticalities in the cooling of energy production plants, and cause disruptions in transport.”
The study is based on climate simulations, and therefore the results should be taken more as a warning than a certainty. A warning of the risks we run in the future, and of the importance of being prepared, with adequate policies. “Our results emphasize the need for continued attention to mitigation and adaptive capacity – the authors write in the conclusions of the study – given the unprecedented changes we could see in the next 20 years even in a low-emissions scenario”.