Mapped: How climate change affects extreme weather around the world

In 2004, a trio of researchers published a study that accomplished something never seen before. They calculated the specific contribution that human-caused climate change made to an individual extreme weather event.

The extreme event in question was the European heatwave in the summer of 2003. Week upon week of extreme heat had a devastating impact, killing more than 70,000 people across the continent.

The scientists worked out that human influence had at least doubled the risk of such an extreme heatwave occurring. The findings made headlines around the world.

The study kick-started the scientific field of “extreme event attribution”.

Attribution studies calculate whether, and by how much, climate change affected the intensity, frequency or impact of extremes – from wildfires in the US and drought in South Africa through to record-breaking rainfall in Pakistan and typhoons in Taiwan.

To keep track of this rapidly growing field of research, Carbon Brief has mapped every published study on how climate change has influenced extreme weather.

This latest iteration of the interactive map (below) includes more than 600 studies, covering almost 800 extreme weather events and trends.

Across all these cases, 74% were made more likely or severe because of climate change. This includes multiple cases where scientists found that an extreme was virtually impossible without human influence on global temperatures.

Around 8% of the events and trends in the map were made less likely or severe by climate change.

This means that, overall, 85% of the events and trends included in the map were found to have been influenced by human-caused climate change.

In the remaining 15% of cases, the studies either found no human influence (10%) or they were inconclusive (8%), often due to insufficient data.

First published in July 2017, this is the seventh update to Carbon Brief’s map.