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Heat waves, droughts and fires may soon hit together as 'new normal,' study finds

Heat waves, droughts and forest fires are some of the extreme climate-related events that are expected not only to become more frequent but also to increasingly strike at the same time. This finding emerges from a new study led by Uppsala University, in which researchers have mapped the impact of climate change in different regions of the world.

In a new study in the journal Earth's Future, researchers from Uppsala University and Belgian, French and German universities have shown that in the near future several regions of the world will no longer just be affected by isolated climate-related events. Instead, several different events will occur concurrently or in quick succession.

"We have long known, for example, that there will be more heat waves, forest fires and severe droughts in many regions—that in itself is no surprise. What surprised us is that the increase is so large that we see a clear paradigm shift with multiple coinciding extreme events becoming the new normal," says Professor Gabriele Messori, the study's lead author.

Using models to predict the future climate—temperature, rainfall, wind and so on—is a common method in climate research. In this study, the researchers have gone a step further by feeding that data into additional models that deliver information on the concrete impact on society.

By calculating the effect of climate change on, say, the risk of forest fires or floods, a clearer picture emerges of how different regions of the world might actually be affected. The analysis examines what will happen between 2050 and 2099. The researchers looked specifically at six types of events: floods, droughts, heat waves, forest fires, tropical cyclone winds and crop failures.

Heat waves and forest fires a recurrent feature

The study shows that combinations of heat waves and forest fires will increase sharply in almost all regions of the world, except where there is no vegetation, as in the Sahara. Heat waves and droughts will become a recurrent feature in areas such as the Mediterranean region and Latin America. Areas that now generally experience isolated events, such as the Nordic countries, will also be more frequently affected by heat waves and forest fires in combination.

"The summer of 2018 in Northern Europe was characterized by unusually high temperatures and widespread forest fires—which at the time was regarded as an exceptional event. In a few decades, it may not be so unusual," says Messori.

Poses new challenges for preparedness

The researchers' analysis covers several possible emission scenarios. However, the main focus is on a medium scenario, which is considered realistic given current emission trends.

"It is important to emphasize that this shift that we see does not only occur if we look at the most extreme case, where we do nothing to reduce our emissions, but also if we consider a less pessimistic scenario. From a societal perspective, we need to broaden our preparedness to deal with these co-occurring extreme events. We are going to face a new climate reality that we have limited experience of today," says Messori.