Extreme Weather is Battering the World. What's the Cause?

“More than 900 billion voters need to go out in the outdoors and queue … for hours and hours under the sun,” said Leena Rikkila Tamang, Asia director of IDEA, a Sweden-based pro-democracy NGO. “We see a clear dip in voter turnout in comparison to the 2019 elections.”

The heatwave in India was 45 times more likely due to climate change and was 0.85 degrees Celsius hotter than it otherwise would have been, according to the World Weather Attribution (WWA). The WWA is an initiative of scientists investigating whether and to what extent human-induced climate change plays a role in recent extreme weather events.

“There is absolutely no doubt that as long as we continue to burn fossil fuels and, therefore, increase the concentration of greenhouse gases in the atmosphere, these heatwaves will become more frequent, more severe, and longer in their duration,” Friederike Otto, who leads the organization, told DW.

The damage caused by extreme weather depends on the vulnerability of the population. Even a seemingly small temperature increase can cause major harm. 

“In countries like India and other parts of South Asia, where lots and lots of people are working outdoors, they are much more exposed and more vulnerable to even relatively small changes in extreme heat,” said Otto. 

Did Climate Change Play a Role in the Brazil Floods?
More than 100 people have died so far in severe floods in the southern Brazilian state of Rio Grande do Sul, which has also caused billions of dollars of damage.

Almost 1.5 million people have been displaced, in what is reported to be the biggest case of climate migration in the country. The state government is even considering moving entire cities to avoid future catastrophes.

Some scientists have already pointed to the effects of climate change, on top of ongoing warming from El Nino, to explain the floods.

One study, published by the French group Laboratoire des Sciences du Climat et de l’Environnement [Climate and Environment Sciences Laboratory], found the heavy rainfall that led to flooding could mostly be ascribed to human-driven climate change.

WWA is working on its own study, but Otto says previous floods in the country were clearly linked to climate change. 

Vulnerability also plays a highly significant role in the damage caused by floods, with some engineers pointing to a lack of preparedness and infrastructure issues. 

Did Climate Change Make the Recent Glut of Tornadoes in the U.S. Worse?
The US has been buffered by an high number of tornadoes this year. 

Over a period of four days, more than 100 tornadoes hit the Midwest and the Great Plains, “causing significant damage and loss of life,” said officials.

The National Weather Service in Omaha, Nebraska, set a record by issuing 48 tornado warnings in a single day.

But the causes of tornadoes are incredibly hard to pin down, because they are so localized. Climate change attribution studies work best on large-scale events over big areas, such as heat and cold extremes, and droughts. 

With the exception of tropical cyclones in the North Atlantic, climate change has not been linked to increased wind speeds, especially over land, according to Otto.

“Given that we don’t see changes in other kinds of wind speeds or other kinds of storms, I wouldn’t expect to see a huge change, but that might be quite different for tornadoes because they are also a different phenomenon.”

Essentially, scientists can’t say what kind of role climate change played or if it did at all.

Hasn’t Extreme Weather Always Happened?
History is awash with examples of extreme weather, even before the cogs of the Industrial Revolution began turning and humans started burning the fossil fuels responsible for climate change in earnest. Such events are natural phenomena, but climate change has very clearly made them far more likely and destructive, say experts. 

Before the 1990s, about 70 to 150 weather and water-related hazards were reported per year. Since 2000, 300 extreme events have been registered annually. Even with underreporting in the past, “the difference is unquestionable,” said WMO’s Alvaro Silva. 

Alistair Walsh is an environment reporter at DW. This article was edited by Jennifer Collins, and it is published courtesy of Deutsche Welle (DW).