Where climate change until recently seemed like an out-of-bed show, this summer was almost inevitable. Half of Europe has been suffering from severe drought for weeks. Vacationers in France and Spain were brutally surprised by the rapid progression of forest fires. One third of Pakistan is under water. Weather records not so long ago are breaking again.
Did scientists actually predict such extremes, or does this essentially give us a glimpse into the future of a planet that has gotten too warm?
Scientists were also surprised
Climate scientists regularly say they have been surprised by extreme events that until recently were considered impossible. For example, last year in western Canada about 50 degrees were tapped. Leading climate expert Geert Jan van Oldenburg, who died at the end of last year from the effects of cancer, said: Norwegian Refugee Council: “If you had asked me a few months ago: Is this possible? I would have answered ‘No’.”
Many people will have the same feeling about heat records this summer. Who would have thought that London would sweat in temperatures over 40 degrees? The weather in England at the end of July was surprisingly similar to the hypothetical weather forecast made by the British KNMI for 2050 not so long ago. Are we witnessing now what was already predicted before 2050?
“It’s bound to see surprises,” says Bart van den Hork, affiliated with Deltares and VU University (VU) Amsterdam. “50 degrees in Canada was completely beyond the weather statistics. The amount of rain last summer in Limburg, Germany and the Ardennes too. Even in the current already warm climate, like heavy rain It should only happen once every 400 years.”
And the belief is that after a few days in the Chinese province of Henan, more rain fell, 617 mm in three days. For comparison, in the Netherlands, an average of 850 mm falls per year.
One third of Pakistan is under water
Pakistan is currently suffering from an unprecedented situation flood. The monsoon brought five to six times as much rain this year as the long-term average. As if that wasn’t enough, the heat is also adding more meltwater from many mountain glaciers. As a result, a third of the country, which is 19 times the size of the Netherlands, is under water.
How does extremism change?
By definition, extreme weather is rare, so applying statistics to it is complicated. Even with a relatively small shift in average weather, extremes will change even more, as can be seen from the image below: Warm phenomena are more common, and we are experiencing extremes of extreme heat, which were practically impossible before. If he is selected again by dice, he will now have another 7.
Every heat wave that occurs today is Stronger and more bearable Because of Human Climate Change, Ben Clark and Frederick Otto, both affiliated with World Weather Attribution . write, The network, in which Van Oldenburg also participated.
heavy rain
It is difficult to make a general statement about the chances of extreme precipitation. This is not surprising, because there are a lot of factors that can affect the amount of precipitation in a particular area. “There is therefore more variation in precipitation than temperature. But even then, we are increasingly seeing heavy rainfall that is clearly outside the statistics,” says Sjokji Philip of KNMI.
Over most of the Earth, intense precipitation is increasing due to human warming because the warmer air can hold more water vapor. When it rains, they often fall into buckets. At the same time, higher temperature also increases evaporation, which increases the risk of drought and wildfire in some areas. The Netherlands is also increasingly facing drought.
Due to climate change, periods of drought are becoming drier and showers more severe:
Is extreme weather worse than expected?
“I told you so,” many climate scientists will think — though they would have preferred to be proven wrong. Predictions based on climate models and weather statistics have long shown that we can expect an increase in extreme weather events.
Similarly, Gavin Schmidt of NASA and Goddard says: “But whether they are going faster than expected is a difficult question, because such extremes are still statistically rare. Therefore, we don’t know very well to what extent the trend in extremes aligns or differs. Between Climate models and observations”.
More heat waves than expected
An exception to this, according to Diem Como, associated with VU and KNMI, are heat waves in Europe. These are increasing faster than elsewhere and climate models predict. according to Recent Research Led by Cuomo, this is due to the jet stream, strong winds high in the atmosphere. It moves more slowly because the poles are warming more than the equator.
As a result, the large rings in the jet stream stay in place for longer, and in their wake also the pressure zones that affect our weather. For example, if we receive air from the south for a long time, then temperatures may rise more and more. The Earth is getting drier, raising temperatures even higher.
Climate models under-estimate “Such extremes are long lasting,” says Michael Mann of the University of Pennsylvania. “One of the main reasons for this is that climate models are not yet able to capture the dynamics of the jet stream well.”
