Century summer in series

In 50 years, almost every summer will be hotter than all previous heat records

Summer record heat will be the norm in 50 years © Dustin Phillips / CC-by-sa 3.0
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Hotter than all previous records: in just 50 years, it could get hotter than ever before in almost every summer - and that's what new climate forecasts show in many parts of the world. In Central Europe and much of North America, Africa and Asia, the probability from 2061 is 90 percent that the summer temperatures exceed previous local heat records. "Century summer" would then be the rule.

Our summers are already warmer on average than ever before in the last 2, 000 years, as recently discovered by climate researchers. Climate change is responsible for three-quarters of the heat waves of the recent past - studies prove this as well. And researchers are already warning that some parts of the world, including the Middle East, could become nearly uninhabitable due to the summer heat.

How are the summers?

Flavio Lehner of the National Center for Atmospheric Research (NCAR) in Boulder and his colleagues have now investigated how our future summer climate will develop. "This is the first time that the risk of summer record heat has been so comprehensively simulated and determined as a function of greenhouse gas emissions, " says Lehner.

For their study, the researchers performed simulations of past and future summer temperatures, in which they not only varied greenhouse gas emissions, but also other weather-determining factors such as weather conditions, atmospheric currents and the like. To capture the full range of possible natural variations, they also considered volcanic eruptions and other climate-influencing events.

Almost every year record heat

The result: in future parts of the world, there is no way around future record summer. For Central Europe, large parts of Africa, Asia and the New World, the probability of more than 90 percent is that summer temperatures from 2061 will exceed all previous local records. "That means that almost every summer will be as hot as today's warmest, 'century summer', " the researchers report. display

Probability for summer temperatures beyond historic records with undiminished CO2 emissions (A), with reduced emissions (B) and the effect of reduction (C). Lehenr et al./ CLimatioc Change / CC-by-sa 4.0

According to forecasts, only a few regions in which traditionally the summer climate fluctuates greatly in any case, the researchers say, are less prone to such permanent summer heat records. Late record summer areas include Alaska, parts of the US, Scandinavia, Siberia, and Australia, with "only" 50% risk.

More summer heat even with effective climate protection

The fatal thing about it: this prognosis is true under the assumption of almost unchanged greenhouse gas emissions. But even if we managed to substantially reduce emissions, for some regions this would have little effect on summer warming, as the simulations showed. Nevertheless, the US East Coast, as well as northeastern Africa, Indonesia and parts of China would nevertheless experience 90 percent record summer serial production.

Central Europe would fare a little better if climate protection were to be effective in good time: Here, the likelihood of getting constant heat records drops to only 50 percent, according to Lehner and his colleagues. Even parts of Brazil and China could then be among the winners of climate protection. "The potential for risk reduction is highest in some of the world's most populous areas, " say the researchers.

How well will we be able to adapt? NASA

"Real burden for the societies"

In any case, a large part of the world's population lives in regions that will experience a sharp increase in summer temperatures in the future, as the researchers emphasize. And that can lead to significant problems.

"Extremely hot summers are a burden for companies, " says Lehner. "They increase the risk of health problems, can damage crops and increase drought. Such summers are therefore a true test of how well we can adapt to rising temperatures. "(Climatic Change, 2016; doi: 10.1007 / s10584-016-1616-2)

(National Science Foundation, 14.06.2016 - NPO)