If you think 2 degrees of global warming is still manageable, you may be mistaken. Researchers at the Helmholtz Centre for Environmental Research in Leipzig, together with TU Dresden, have found that extreme climate impacts can occur even at this level of warming. The study was published in the journal Nature.
Until now, particularly severe climate impacts were mainly expected at warming levels of 3 or 4 degrees. These assessments were usually based on average results from many climate models. But this is precisely where the problem lies. Individual model projections vary widely. Some show much stronger changes at 2 degrees than others do at 4 degrees. “In terms of responsible risk assessment, we should therefore look beyond the most likely developments and also consider extreme scenarios that could have serious social or ecological consequences,” explains lead author Dr. Emanuele Bevacqua.
The limits of the models
The study reflects a broader shift in climate research. For a long time, the focus was on average outcomes. Today, it is increasingly clear that extreme events are what matter most. For society and the economy, it is not averages that matter, but concrete events such as droughts, heavy rainfall or wildfires. The new approach makes these risks more visible by focusing on particularly vulnerable regions. At the same time, it highlights the limits of current climate models. They do not provide exact predictions, but a range of possible futures. In the worst case, these could be far more severe than expected.
“Our results do not mean that a 2-degree warming would be as severe overall as a much higher level of warming,” explains co-author Prof. Dr. Jakob Zscheischler. “Rather, they show that extreme impacts in particularly vulnerable or socially important sectors can occur even at 2 degrees.” A 2-degree warming is therefore no guarantee of moderate consequences.
Original publication:
Emanuele Bevacqua, Erich Fischer, Jana Sillmann and Jakob Zscheischler. Moderate global warming does not rule out extreme global climate outcomes, Nature
