The US and Canada: Climate Change in North America without a heat wave “almost impossible”

46.6, 47.9, 49.5 degrees: the Canadian city Liton three temperatures broke records last week – on three consecutive days. The highest value ever measured Canada It is 45 degrees, it was in 1937. A day after the latest information, the location was destroyed by fire Almost completely destroyed.

Is Lytton’s fate a sign of a growing climate crisis? According to the findings of a quick study by leading climate scientists, it is available for SPIEGEL, one can read it for sure.

Last week, not only in Canada, to the west of the severe heat wave United States Furious, without the impact of climate change “almost impossible”. This is the result of an analysis by the World Meteorological Organization, which includes 27 researchers from Princeton University University of Oxford, ETH Zurich, in which the involved include Columbia University and the German Weather Service.

How climate change is likely to have risen to the possibility of such a heat wave two different interpretations and therefore unreliable.

Many factors may have worked together over the months, especially in the western United States, including the severe drought and abnormal atmospheric circulation of smoking. “Heat Dome” also known as. It is a stable high-pressure system, the creation of which generates heat, the heat is in the region as long as an hour.

The jet stream is affected considerably by the high-pressure system is sluggish. In this region, hot tropical and subtropical air accumulate, which sinks to the ground, compressing the air below and heating it further.

According to research, the recorded temperature can be explained by the rare combination of climate change and heat dome.

Does the climate system exceed important limits?

Alternatively, researchers think the most troubling explanation is imaginary. Accordingly, it is also credible that the global climate system already exists, with average global warming plus 1.2 degrees from pre-industrial timesNon-linear limits exceeded. From this point on, slightly extra global warming can lead to a significant increase in extreme temperatures. Events such as the current heat wave than prescribing of current climate models means that there are already too high. Additional studies to examine this very closely, write the scientists.

First and foremost, climate change has increased the chances of such a very rare event actually occurring 150 times. In addition, the current heat wave was two degrees warmer than expected without the influence of climate change. Man-made emissions would not only increase the likelihood of such extreme weather conditions, but also increase their severity.

If global warming continued to increase by two degrees compared to pre-industrial times, the results of the study suggest that the heat wave would have been another degree warmer, and instead of every 1000 years, as is currently statistically significant, a heat wave of this magnitude would occur once every five to ten years.

The researchers emphasize that the new temperature records are beyond previously measured values, making it difficult to determine exactly how unusual such a phenomenon is in current climatic conditions.

“What we are experiencing here is unprecedented,” said Frடdரric Otto of Oxford University, who was involved in the study. “This event shows us that we cannot rule out the possibility of experiencing global warming today as we would have expected only if global warming had advanced further.” For Otto, it is not normal for temperature records to be above four or five degrees Celsius. “Climate change is a very rare instances, such as frequently. Zurich, the Swiss Federal Institute of Technology of the Institute for Atmospheric and Climate Science cenaviratne says Sonia.

It is much hotter under today’s conditions

It is even more difficult to link individual weather events directly to climate change. Human fingerprints can only be read from the increase of certain extreme weather conditions and their increased intensity.

The “World Meteorological Organization” seeks to close this gap by examining the role of man-made CO₂Emissions were analyzed during unusual weather events. A team of international scientists uses an established approach that integrates observed trends with climate models.

The underlying idea is: how realistic is the extreme weather that counts. To do this, they simulate thousands of times on the computer how accurate this weather condition would have been in pre-industrial times and today. Results of the comparison reveals the influence of climate change.

With this principle, there are many for researchers Heat waves in the past few years, examined. The analyzes came to a similar conclusion: extreme heat is high under today’s conditions.

According to research, climate change also increases the risk of heat waves Europe. In the heat of the heat of the investigation France Since the end of June 2019, the probability of a warming global warming period increasing at least five times, and even a sample coming to a hundred factor.