Emerging threatsFuture summers could regularly be hotter than the hottest summers on record
In fifty years, summers across most of the globe could regularly be hotter than any summer experienced so far by people alive today, according to a new study. If climate change continues on its current trajectory, the probability that any summer between 2061 and 2080 will be warmer than the hottest on record is 80 percent across the world’s land areas, excluding Antarctica, which was not studied. If greenhouse gas emissions are reduced, however, that probability drops to 41 percent, according to the study.
In fifty years, summers across most of the globe could regularly be hotter than any summer experienced so far by people alive today, according to a study by scientists at the National Center for Atmospheric Research (NCAR).
If climate change continues on its current trajectory, the probability that any summer between 2061 and 2080 will be warmer than the hottest on record is 80 percent across the world’s land areas, excluding Antarctica, which was not studied.
If greenhouse gas emissions are reduced, however, that probability drops to 41 percent, according to the study.
“Extremely hot summers always pose a challenge to society,” said NCAR scientist Flavio Lehner, lead author of the study. “They can increase the risk for health issues, but can also damage crops and deepen droughts. Such summers are a true test of our adaptability to rising temperatures.”
The study is part of an upcoming special issue of the journal Climatic Change which will focus on quantifying the benefits of reducing greenhouse gas emissions. The research was funded by the U.S. National Science Foundation (NSF) and the Swiss National Science Foundation.
Simulating a range of summers
NCAR says that the research team, which includes NCAR scientists Clara Deser and Benjamin Sanderson, used two existing sets of model simulations to investigate what future summers might look like. Both had been created by running the NCAR-based Community Earth System Model fifteen times, with one assuming that greenhouse gas emissions remain unabated and the other assuming that society reduces emissions.
The Community Earth System Model is funded by NSF and the U.S. Department of Energy. The simulations were run on the Yellowstone system at the NCAR-Wyoming Supercomputing Center.
By using simulations that were created by running the same model multiple times, with only tiny differences in the initial starting conditions, the scientists could examine the range of summertime temperatures we might expect in the future for the “business-as-usual” and reduced-emissions scenarios.
“This is the first time that the risk of record summer heat and its dependence on the rate of greenhouse gas emissions has been so comprehensively evaluated from a large set of simulations with a single state-of-the-art climate model,” Deser said.
