Human-induced global warming has made Europe, North America and China at least 20 times more likely to experience severe droughts like this summer than they were more than 100 years ago, scientists said Wednesday. Stated. This is the latest evidence of how climate change, caused by the burning of fossil fuels, is threatening the world’s food, water and electricity supplies.
A major factor in this year’s drought was extreme heat across much of the northern hemisphere, researchers report in a new study. Without the impact of greenhouse gas emissions, it would have been “virtually impossible” to have average temperatures this high over such a large area, scientists say.
Across the Northern Hemisphere, north of the tropics, scientists have found that soil conditions like this summer’s dryness are about 1 in 20 more likely to occur each year. Global warming has increased this possibility, they said, but they cautioned that the exact size of the increase has a wide range of possibilities, given the difficulties involved in estimating soil moisture on a global scale.
Maarten van Aalst, director of the Red Cross and Red Crescent Climate Center and one of the 21 researchers who produced the climate change report, said: This is new research as part of the World Weather Attribution initiative, a collaborative research dedicated to rapid analysis of extreme weather.
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“The impact is very clear to people right now, they are being hit hard,” said Dr. Van Aalst.
Extreme summer dryness, which devastates crops, paralyzes river commerce and strains hydropower on the planet, will be a major problem in itself. But this year, world food and energy prices were already rising for other reasons, such as Russia’s war in Ukraine.
record heat It began to choke Europe in May, with roasting temperatures drying out rivers and igniting protracted wildfires over the next few months. 11,000 excess deaths France and 8,000 in Germany, according to estimates.Summer wildfires across the European Union baked total area That’s more than double the average of the last 15 years.
China had the most brutal summer since modern records began in 1961. national meteorological authorities, hot and dry weather is reducing hydropower generation in the manufacturing-rich south. To keep production lines running in auto and electronics factories, China has dug and burned more coal, increasing its contribution to global warming.
and in America, close to half According to the National Oceanic and Atmospheric Administration, 48 states in the contiguous United States have experienced moderate to extreme drought this summer. The Southwest and parts of California have been hit by a massive drought that has lasted more than 20 years.
To assess the impact of global warming on droughts and other extreme weather events, scientists are using computer simulations to compare real-world climate and the greenhouse effect that humans have not burned for more than a century. I’m looking at both different climates that don’t emit gas. They see how often weather events as severe as the one in question occur in both worlds. This difference suggests how much global warming was to blame.
Scientists at World Weather Attribution found last month that climate change has very likely exacerbated devastating floods in Pakistan this summer. Previously, they found that global warming is making Britain’s record-breaking July heatwave hotter and more likely to occur.
Drought is more difficult to study than extreme heat. Scorching temperatures and low rainfall aren’t the only factors affecting them. Local landscape features also play a role. Moreover, although sensor technology is constantly improving, it is difficult to reliably estimate soil moisture content over a large area compared to temperature and precipitation measurements.
The authors of the new report examined soil moisture levels in two geographic regions from June to August. The entire northern hemisphere north of the tropics and the continental belt of Europe from France to Ukraine. They also looked at both regions’ temperatures and precipitation this summer.
In the Northern Hemisphere region, the earth has already warmed by 2.2 degrees Fahrenheit (1.2 degrees Celsius) since the late 1800s, so scientists found that the first few feet of soil below the surface this summer had low moisture levels. It was at least 20 times more likely compared to a virtual world that doesn’t burn fossil fuels.
This makes droughts this summer already occurring “relatively frequently” in our current climate, says Sonia I. Seneviratne, a scientist at the Swiss University of Zurich and another author of the study. said. But if the planet were to warm up to 3.6 degrees Fahrenheit (2 degrees Celsius) above pre-industrial temperatures, as is likely under current government policies, such aridity could be 15 times more likely. She said there is
“Basically, it will happen every other year, more or less,” Dr. Seneviratne said.
In Western and Central Europe, researchers have found that global warming has increased the likelihood of dryness this summer by three to four times. This does not mean that Europe is less susceptible to climate change than other parts of the Northern Hemisphere, they said. Friederike Otto, a scientist at Imperial College London and another study author, says that because the area above the tropics is smaller than the northern hemisphere, natural variations in weather canceling each other out are more likely to occur in larger areas. said to be less than
“Climate change has definitely played a big role here,” said Dr. Otto. However, she continues, “precise quantification of its role is less certain for soil moisture than, for example, when looking at heavy rainfall.”