Critical climate identification tools for understanding extreme events

A combined heat and drought event in the western US, simultaneous ocean and land heat waves in the Pacific Northwest, an off-the-charts heat wave in South Korea, and wildfires in Cape Town, South Africa, are some of the most recent. According to the extreme weather events caused by man-made climate change New research External link It was posted today on the Bulletin of the American Meteorological Society (BAMS) website.

Now in its 11th year, Climate Insights presents new peer-reviewed analyzes of extreme weather and climate across the world in 2021 and 2022. It features research from NOAA and other leading international climate scientists on extreme weather happening around the world. Including the US, UK, South Korea and China. Research teams use both historical observations and model simulations to determine how climate change has affected specific weather events.

“These studies contextualize recent extreme events, explain how the risk for them is changing over time, and how climate change has made them more severe or dangerous,” said NOAA Chief Scientist Sarah Kapnick, Ph.D. “By helping to measure these evolving risks and their causes, we can help communities plan and prepare for the future with a better understanding of what’s to come.”

“A key finding from this new research, both at BAMS and in the scientific literature, is that climate change is far from the historical record,” said climate scientist Stephanie Herring. NOAA’s National Center for Environmental Information and one of the report’s authors. “To better understand what we might experience in the future, we need to continue to examine how these events change over time and consider the possibility that we may be underestimating future risk.”

A study found that the average temperature in South Korea in October 2021 was 7 degrees Fahrenheit higher than the average observed between 1991-2020, corresponding to a one in 6,250 year event. However, the climate model used in the study predicted that this type of heat wave could become the new norm in South Korea by 2060 “without reducing greenhouse gas emissions.”

“The extreme nature of these events is alarming,” Herring said.

Co-occurring events – previously only studied separately – are also examined, which means that the probability of multiple accidents occurring at the same time is also changing. For example, one paper studied the impacts of the 2021 ocean and land heat wave on people, trade, infrastructure, and fish across Asia, including Japan, Korea, and China. Such an event is 30 times more likely to occur today due to climate change, and is more likely to occur every 1.5 years by mid-century under conditions of high greenhouse gas emissions.

Additional findings from studies of some of the climate characteristics published in this report show the ways in which climate change has affected extreme events.

Drought

• Climate change and a strong La Niña combined to increase the risk of severe drought sixfold, as seen in California and Nevada from October 2020 to September 2021, combined with longer periods of high temperatures.
• A study found that Iran is now 50% more vulnerable to severe and prolonged droughts in 2020 and 2021, largely due to greenhouse gas emissions.

Heat

• Anthropogenic (human-caused) warming has made a record-breaking February 2021 winter in East Asia 4 to 20 times more likely.

Fire

• Climate models suggest that severe weather associated with the April 2021 Cape Town wildfires is 90% more likely in the warmer world.

Heavy rains and floods

• Heavy rainfall in England in May 2021 was 1.5 times more likely to occur as a result of anthropogenic climate change. Persistent low pressure also contributed to the rain.

Agricultural influences

• On the southeastern Tibetan Plateau, the constant cloud cover was very difficult to reduce vegetation growth. One study attributed the phenomenon to unusual southerly winds, pollution and greenhouse gas warming.

The new study also includes a review article on how climate change science can support informed decision-making by water resource managers to prepare for future droughts.

“Human-caused climate change is the most disruptive to the Earth system,” said Paul Higgins, associate executive director of the American Meteorological Society. “As this new study shows, we should expect it to lead to serious events. We should do everything we can to help people, and all life, thrive despite this risk.”

The extreme weather events studied in the Explaining Extreme Events series were selected by individual researchers to examine the utility and skill of climate analysis methods. Events during the 2011-2021 period do not represent a comprehensive analysis. Of the more than 200 research findings published in this series, more than 80% identified a strong link between extreme events and climate change.

To learn more, visit Explaining the extreme events website. External link