World Weather Attribution

The World Weather Attribution project is a first of its kind initiative that performs "extreme weather autopsies" immediately after an extreme weather event occurs, identifying the human fingerprint in certain types of extreme weather events days—instead of months—after the event occurs.

“The goal of this ambitious effort is to use peer-reviewed science to provide decision-makers, the public and the media with early, science-based answers to the questions of whether and to what extent global warming caused by greenhouse gas emissions played a role in an event’s probability,” said Dr. Heidi Cullen, Climate Central’s Chief Scientist.  “Our team believes that a careful science-based assessment is extremely valuable, even in cases where we can’t provide hard numbers, “ said Dr. Maarten van Aalst, Director of the Red Cross Red Crescent Climate Centre. “It is important to recognize that "we don't know" or "there is no significant trend" are also valid findings.” 

This work will also help answer questions about trends in risk and vulnerability, and the role of human activity in extreme weather.

There are four possible outcomes of our attribution analysis of an event:

• Global warming increased its likelihood.
• Global warming reduced its likelihood.
• Global warming had no detectable role.
• Our analysis methods were unable to give information.

By providing a clear scientific statement (including about what may be uncertain), our objective is to inject more rigorous analysis and science-based information into coverage of — and public discourse on — extreme weather and its relationship with climate change.