How will climate change affect extreme weather events?

When extreme weather events occur, people often question whether climate change is to blame. A decade ago, scientists would not have been able to answer this question, but today attribution science is helping us to understand the link between human-induced climate change and extreme weather.  Research in this field involves the study of weather events and the use of models of climate change in order to determine the extent to which a weather event may be made more likely or more severe by climate change. Such research can be challenging but in recent years, scientists have developed ways to do it with increasing confidence. 

A new study, published today in the first issue of Environmental Research: Climate, a new academic journal published by IOP Publishing, warns that there are still large gaps in the published attribution research literature, and that these gaps hide the full extent of climate change damage. 

Extreme weather events have always taken place and it is not likely that climate changes cause any of them directly. However, scientists have been warning that extreme weather is likely to become more frequent and severe in the face of changes to the atmosphere and climate. Attribution science allows us to quantify the influence of climate change more precisely, and to show not only that the link between extreme weather and climate change is real, but also how strong it is. 

Researchers from the University of Oxford, Imperial College London and the Victoria University of Wellington reviewed the impacts of five different types of extreme weather events and to what degree these damaging events could be attributed to human induced climate change. They combined information from the latest Intergovernmental Panel on Climate Change reports and results from a fast increasing body of attribution studies, in which weather observations and climate models are used to determine the role that climate change played in specific weather events.

The researchers found clear variation in the extent to which extreme weather events can be linked to climate change. For some weather events, such as heatwaves, the link is unequivocal across the world. For others, such as tropical cyclones, the role that climate change plays is more variable and differences exist in the extent to which these events are influenced by climate change in different regions of the world. 

“The rise of more extreme and intense weather events such as heatwaves, droughts and heavy rainfall have dramatically increased in recent years, affecting people all over the globe. Understanding the role that climate change plays in these events can help us better prepare for them. It also allows us to determine the real cost that carbon emissions have in our lives,” said study lead author Ben Clarke from the University of Oxford.

National weather data is not always made available to the public, especially in lower- and middle-income countries. These are the countries that often suffer the impacts of climate change more severely, but the lack of available weather data can hamper research efforts. For example, in Somalia where droughts are common, disorderly regime changes have resulted in disruptions in the collection of weather measurements. In South Africa, corruption and looting of the public coffers has meant a shortage of funding for weather reporting facilities, and in Poland high fees are charged for access to weather data, precluding the use of this data in publicly funded research. 

“We really don’t have a comprehensive overview or detailed inventory of what impacts climate change is having today, yet,” said study co-author Dr. Friederike Otto. “But we do now have the tools and advanced understanding to create such an inventory, but these need to be applied more evenly across the world to improve our understanding in areas where evidence is lacking. Otherwise we are denying countries the knowledge to make the best use of sparse funds and improve chances for people to live safely and adapt to the changing climate.”

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By Alison Bosman, Earth.com Staff Writer