Attribution science, which quantifies the influence of human activity on specific heatwaves, droughts and floods, has developed rapidly in the past decade
The UN’s climate science panel is set to publish a major report in August on the physical changes to our world occurring and projected to happen as a result of human activity, from extreme weather to ocean acidification.
It will be the first comprehensive review of the scientific literature since 2013, when the Intergovernmental Panel on Climate Change (IPCC) started its last round of assessment reports, AR5.
Attribution science, which looks at how much human activities lead to climate change, is likely to feature heavily in the report. Here we give an overview of the scientific developments of the past eight years.
AR5 concluded that human influence on the climate system is “clear.” Today scientists say climate change is, without doubt, caused by us. A 2021 study concluded that humans have caused all of the warming observed since the preindustrial period.
Since the last IPCC report, there has been an explosion of attribution studies finding that specific heatwaves, droughts, tropical cyclones and other extreme events were more likely or intense because of climate change. Recent studies have shown that extreme events such as the Siberian heat wave in 2020 would never have happened without humans pumping greenhouse gases into the air.
Since AR5, attribution science has become more “impact-oriented”, Sjoukje Philip, a climate scientist from the World Weather Attribution (WWA) group, told Climate Home News.
That means more studies focusing on the societal impacts of extreme weather events, such as the 2016 study which found that 506 of the 753 fatalities during the Paris heatwave in 2003 were a result of climate change.
“We wanted to see how much human-induced climate change contributed to mortality,” Dann Mitchell, one of the study’s authors and professor of climate change at Bristol University, told Climate Home News. “Since the last IPCC report models have become more advanced and we have better ways of collecting climate and health data,” he said.
The increase in attribution studies is due to more precise climate models and peer-reviewed methods which allow scientists to rapidly and accurately analyse extreme events, according to Philip. This also helps with communication. “If you can do the attribution one week after the event, it’s still news,” she said.
Scientists are now able to carry out attribution studies within a few days of an event occurring. In some cases they can do the analysis while the event is still going on. Scientists from the WWA group published a study in 2018 showing that climate change made Europe’s heatwave twice as likely, while it was ongoing.
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Climate Home News, 4 August 2021. Full article.
