Unrelenting drought in California, extreme rainfall in the UK, record heat in China – some of the worst weather events to hit the world in recent years are more likely to happen because of the climate crisis, new research has found.
An analysis of extreme events in 2021 and 2022 showed that many of these extremes have been exacerbated by global warming, and in some cases would have been nearly impossible in terms of their severity had humans not changed the climate by burning fossil fuels.
“The extreme nature of these events is very alarming,” said Stephanie Herring, a climate scientist at the US National Oceanic and Atmospheric Administration (NOAA).
“We need to understand if these events are signs that things are getting warmer faster than we expected.” We know that extreme heat will get worse, and additional research will help us better quantify future changes.
The footprint of climate change is being identified across the planet. The risk of extreme drought across California and Nevada was exacerbated six times by the climate crisis and the strong periodic La Niña climate event from October 2020 to September 2021, while, conversely, the extreme rainfall that flooded parts of the UK in May 2021 was 1.5 times more likely due to global warming.
A severe heat wave in China in February 2021 is made between four and 20 times more likely due to human-induced climate change, while an acute drought in Iran in 2021 is now 50% more likely due to human-caused greenhouse gases . pumps into the atmosphere.
A number of other severe impacts can be attributed, at least in part, to the impact of the climate crisis, including weather that caused a dangerous fire in Cape Town, South Africa in 2021 to be 90% more than if we had never warmed the planet, and even constant cloudiness above of the Tibetan Plateau that has reduced vegetation growth, caused, the researchers say, by increased global temperatures along with abnormal winds and localized pollution.
The collection of research, which Noaa presented at the conference on Monday, brings together some of the most recent examples of climate attribution, where scientists have been able to point to the impact of human-caused climate change on individual weather events and disasters.
Previously, Herring said scientists have been reluctant to talk about the impact of climate change on discrete events, preferring more general probabilities, but that this message has “evolved over time as research has increased” into more precise attribution methods.
Using increasingly powerful climate models, along with historical observations, scientists are now able to provide more accurate and rapid estimates of the impact of the climate crisis on specific disasters. The torrential rain that caused devastating floods in Nigeria, Niger and Chad last year, for example, was about 80 times greater because of the climate crisis, one study found.
Herring warned that many of the temperatures now being observed are far above all modern historical norms and are pushing humanity into a new, dangerous state. The heat wave in South Korea in October 2021, for example, was so drastic, at nearly 7F higher than normal, that it would be considered an event that would only happen every 6,250 years. But climate models predict that will become the new normal for South Korea by 2060 if the planet-warming gases are not radically reduced.
The same fate could await the normal-temperature Pacific northwest of the US, where about 600 people died as a heat wave hit the region in 2021. A subsequent study found that the climate crisis made a heat wave 43 times more likely.
“Human-induced climate change is an extreme disruption of the Earth system,” said Paul Higgins, associate executive director of the American Meteorological Society.
“We should expect this to lead to more extreme events, as this new research helps to show.” We must do everything we can to help people, and all life, thrive despite this danger.”