Each heat wave today is more intense due to climate change – New Scientist

According to scientists, it is no longer important to use models to determine whether a heat wave has become more likely due to climate change. Today, climate change plays a role in all heat waves, they say.

Any heat wave that is happening now has become more likely due to climate change. It is therefore no longer necessary to use studies to unravel its role in individual periods of extreme heat, says a scientist who pioneered such “attribution studies”.

Extreme weather conditions

Researchers generally caution against attributing specific extreme weather events to climate change. Heat waves in China and Japan last week would not generally be associated with climate change until “attribution studies” were conducted. These are studies that compare the likelihood of heat waves in a world with a changed climate, versus the likelihood in a world without climate change.

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Such studies, conducted by a climatologist Friederike Otto from Imperial College London, have evolved over the past ten years and can now be played within days. But, says Otto, in the event of a heat wave, we no longer have to wait for that. “I think we can now say with confidence that any heat wave that’s happening right now has been made more intense and more likely because of climate change,” she says. There is no doubt that climate change is an absolute problem game changer this is when it comes to heat waves.

status quo

However, changes in land use can still affect the exact probability. Partly for this reason, Otto says more studies will be needed to find out exactly how more likely and intense heat waves have become due to climate change. “We shouldn’t stop at attribution studies,” she says. But the status quo, with many of these studies being conducted by NGOs, such as the Global Weather Allocation Project what Otto is a part of is “definitely not sustainable,” she adds.

National weather agencies, such as the UK’s Met Office, should conduct more research to understand the impacts of climate change, Otto and colleagues said in a statement. review published last week on attribution studies†

Peter Stott, head of climate attribution at the Met Office, says such work is already underway within the organisation. “We have been researching climate attribution at the Met Office for over two decades, and we are already able to quickly attribute some extreme events using a Peer-reviewed method.’

Luke Harrington from Victoria University of Wellington in New Zealand, who worked with Otto on the study, says heat waves are the fastest-changing type of extreme weather events due to climate change. “You see a greater increase in the frequency of severe heat waves with each additional degree of global warming, compared to the change in the frequency of other types of extreme weather.”

Droughts, forest fires and heavy rains

By comparison, most severe droughts around the world are not attributable to climate change, the report says. The same goes for most wildfires, except that there is high confidence in a link between climate change and the increasingly common wildfires in the western United States. United. But heavy rainfall has increased across most of the world due to climate change, and nowhere in the world has the likelihood decreased.

Heat waves linked to climate change killed 157,000 people worldwide between 2000 and 2020. 80% of people died during the European heat wave of 2003 or the Russian heat wave of 2010. Harrington says that number is almost certainly an underestimate, as heat waves are not monitored in many parts of the world, and often no definition of a heat wave.

Of the total heat-related deaths, only 6.3% of deaths were recorded in Asia, Africa, South and Central America and the Caribbean, despite the fact that almost 85% of the world’s population lives in these regions.