It sounds like something you’ve always suspected: Certain types of extreme weather are becoming more common as a result of climate change, a new study finds. The impact on the frequency of extreme heat is particularly dramatic – resulting in tens of thousands of deaths.
Is this still weather or already climate change? The question comes up again and again in view of the new heat records in Germany and worldwide every year, but up to now it has not been possible to give a clear answer. A research team including the well-known German climate researcher Friederike Otto now finds in a new study: The increasing trend in heat waves is clearly a consequence of climate change. “There is no doubt that climate change is a game changer, worldwide,” Otto said at a press conference.
In their meta-analysis, the research team tried to determine which trends in extreme weather events can actually be attributed to climate change. Their conclusion: The “most dramatic changes” are in the frequency and intensity of heat and cold extremes, according to the study, which is available to ntv.de. According to the authors, the consequences for people worldwide are catastrophic.
According to the study, the probability of extreme heat on land increased fivefold by 2015. ‘As a direct result of climate change, what was once very rare heat is now only unusual, while events now considered ‘extreme’ are achieving temperatures that were once all but impossible,’ the authors write. The phenomenon can be observed on all continents and, according to the IPCC report 2021, is due to human-caused climate change.
This development has deadly consequences: the number of heat-related deaths is increasing worldwide, more than a third of which are due to climate change – which corresponds to tens of thousands of deaths per year. Due to climate change, there are more frequent heat extremes in which the human body is no longer able to cool itself – even the healthiest person – even in the shade and with water supply – would die within a few hours from severe heat stroke, it is said in the investigation.
The authors also warn that heat-related diseases such as heart and lung diseases, kidney failure and electrolyte imbalances are on the rise. The health of fetuses in the womb is also endangered. Heat waves are also associated with an increase in harmful pollutants such as ozone, particulate matter, sulfur dioxide, carbon monoxide and nitrogen dioxide, which put additional strain on the respiratory tract.
The economy is also suffering from the increasing heat: The productivity of workers is decreasing because they “slow down, take more breaks and drink more fluids to stay safe,” says the study, which was published in the journal ” Environmental Research” was published. The researchers put the global losses from this at 280 to 311 billion US dollars per year, especially in developing and emerging countries and in sectors in which work is physically difficult or outdoors – such as in construction.
But there is also a counter-trend: Due to global warming, the number of extreme cold waves is also decreasing significantly, according to the study. In addition, mortality is higher in the cold months than in the summer, especially in temperate latitudes such as Europe and North America. Will the milder winters offset the deadly consequences of extreme heat? Probably not. The authors emphasize that the increase in mortality due to high temperatures is “estimated to be far more important” than the decrease due to less frequent cold extremes. In addition, the influence of cold on health in winter is difficult to separate from other seasonal factors.
The authors also see a clear connection to climate change in the case of other extreme weather events. The frequency of heavy rains increased until 2015. The reason: Due to global warming, the atmosphere could absorb more water, which could lead to heavy rain in some regions. Floods are more frequent in North America, Asia and Europe in particular. However, the trend varies from region to region – heavy rain is increasing in northern Europe, while it is becoming rarer in southern Europe.
The study also confirms an increase in forest fires and droughts as a result of climate change, although the impact is less clear in these cases. With regard to droughts, the influence of climate change would also be overestimated, says climate researcher Otto. She sometimes even considers this to be dangerous, as she demonstrates with the example of East Africa. There, other factors would also have an impact on droughts, such as infrastructure and type of agriculture. If droughts were simply blamed on climate change as “force majeure”, “the local administration would be deprived of any responsibility”.
However, the study does not find any increase in the frequency of tropical cyclones such as hurricanes and typhoons. However, these are increasing in intensity, the authors write. In addition, a slowing down of the storms was observed, which is associated with a higher amount of precipitation.
According to another study published on Monday, the number of tropical cyclones may even have decreased as a result of climate change. The researchers found that there were about 13 percent fewer tropical cyclones in the 20th century than in the second half of the 19th century. However, this study made no statements about the development of the intensity of the storms.
