Europe's Hot, Fiery Summer Linked to Global Warming, Study Shows

https://insideclimatenews.org/news/27092017/heat-wave-lucifer-europe-climate-change-attribution-study

By Bob Berwyn, InsideClimate News
Sep 27, 2017

Global warming made this summer's record heat across Southern Europe—with its wildfires and a heat wave so vicious it was nicknamed "Lucifer"—10 times more likely than it would have been in the early 1900s, scientists said today in a study published by the World Weather Attribution research group. If greenhouse gas emissions aren't cut soon, such heat waves will be the regional summer norm by 2050, the study concluded.

The scientists, from universities and research institutions in Europe and the United States, said they are more certain than ever that human-caused global warming is a key driver of the extreme heat.

As the average global temperature goes up, it becomes easier to pick out the climate change signal, said lead author Sarah Kew, a climate researcher with the Royal Netherlands Meteorological Institute.

•••••

The urgency of improving understanding of the heat-related health risks from global warming was made clear in 2003, when the most extreme European heat wave on record killed more than 70,000 people. The summer of 2003 is still the hottest on record for the whole of Europe, although 2017 was hotter in the Mediterranean region.

A landmark climate attribution study in 2004 determined that the buildup of greenhouse gases from burning fossil fuels made the extreme temperatures of 2003 at least twice as likely as they would have been a world with no human-caused greenhouse gases.

Since then, the global average temperature has increased by another quarter degree Celsius and Southern Europe summers are warming at twice that rate, according to the European Environment Agency. Scientific understanding of the influence of climate change has also advanced.

•••••

"We found that the 2017, heat was not all that rare anymore. Due to global warming, there's a 10 percent chance every year in many places," Kew said. The study's estimates of how global warming increases the likelihood of heat waves are conservative, she said.

In a world with no human-caused greenhouse gases, the chances of having a summer as warm as this one would approach zero, according to the study. With greenhouse gas emissions eventually raising temperatures 1.5 degrees Celsius warmer than pre-industrial times (about a half degree warmer than today), the chances increase to 24 percent. After 2 degrees Celsius of warming, the chances of a having summer like this rise to 42 percent.

French researcher Robert Vautard, who closely studied the deadly 2003 heat wave, said better climate simulations are making studies more accurate.

•••••