"Even a 2°C Rise in Global Temperature Can Cause Extreme Events... Risks Overlooked by Focusing on Model Averages"

Results from German Research Team
"Climate Assessments Based on Model Averages
May Underestimate Extreme Risks"

A new study has found that focusing on average values when assessing global warming may lead to overlooking extreme climate events.

A photo to help understand the article, showing the riverside in Brazil exposed due to drought. Photo by AP Yonhap News Agency

According to Yonhap News Agency on March 26, a research team led by Dr. Emanuele Bevacqua at Germany’s Helmholtz Centre for Environmental Research (UFZ) reported in the scientific journal Nature that their new approach—combining climate impact factors such as heavy rainfall and drought with vulnerable sectors like forests, agriculture, and densely populated areas—shows that conventional climate assessments, which are based on the average values of multiple climate models, may underestimate extreme risks.

Until now, 'worst-case climate scenarios' caused by global warming have typically been presented using the average predictions of various climate models, assuming a global average temperature rise of 3 to 4°C. However, the research team pointed out that this average-based approach may not sufficiently account for extreme changes that could occur in specific regions or sectors.

In this study, the researchers identified key factors of climate impact—such as extreme precipitation, drought, and wildfire risk—and mapped them to vulnerable regions, including forests, agricultural zones, and densely populated areas. By combining these elements, they analyzed climate changes in regions closely linked to certain global climate risks. In addition, they used multiple climate model simulations, which serve as the basis for the UN Intergovernmental Panel on Climate Change (IPCC) reports, to compare the best- and worst-case scenarios for each sector.

As a result, some climate models predicted that in three key sectors—heavy rainfall in densely populated areas, drought in global agricultural regions, and fire risk in forested areas—even a 'moderate' warming of 2°C could lead to more extreme climate events than the model average for a 3 to 4°C rise. In particular, for agriculture, which is directly linked to food security, the study found that a 2°C increase could cause drought to increase by more than 50% in major production areas for corn, wheat, soybeans, and rice.

A wildfire in Chile last January. Photo by AP Yonhap News

Dr. Bevacqua, who led the research, stated, "Out of 42 climate models, 10 showed a much greater increase in drought under a 2°C temperature rise than the average at 4°C," adding, "Focusing only on the model average could conceal such risks." He continued, "There is considerable uncertainty in climate models, and the Earth's climate could change much more dramatically than expected. For responsible risk assessment, we need to consider not just the most likely range, but also extreme scenarios that could have severe social and environmental consequences."

Professor Jakob Zscheischler of Dresden University of Technology, a co-author of the paper, said, "These results do not mean that the risk at a 2°C increase is the same as at 3 to 4°C," but added, "However, in certain vulnerable or socially critical sectors, the effects of warming at 2°C can still be extremely severe."

He further stated, "With global temperatures already nearing a 1.5°C increase, the possibility of severe impacts at 2°C means that swift action is needed to limit warming to lower levels," emphasizing that "these findings should be reflected in climate risk assessments and the development of adaptation policies."

This content was produced with the assistance of AI translation services.