It’s only July, but it has already been a long, hot spring and summer. The contiguous U.S. endured the warmest May ever recorded, and in June, the average temperature was 1.7 degrees Celsius (3.0 degrees Fahrenheit) above the 20th century average. Iowa, New Mexico and Texas set record highs for their minimum temperatures in June, and as of July 3, nearly 30 percent of the Lower 48 was experiencing drought conditions. And it’s not just the U.S. During the first five months of 2018, nearly every continent experienced record warm temperatures, and May 2018 marked the 401st consecutive month in which temperatures exceeded the 20th century average.
Climate change, in other words, is not a hypothetical future event — it’s here. We’re living it. And at a major science conference this month, some of the world’s leading climate scientists said it was changing our world in ways beyond what they’d anticipated.
“The red alert is on,” Laurent Fabius, who was president of the 2015 international climate change negotiations in Paris, told an audience last week at the EuroScience Open Forum, Europe’s largest interdisciplinary science meeting. As of 2015, global temperatures had risen about 1 degree Celsius above pre-industrial levels. “It’s a race against time,” Fabius said, and the political challenge is to avoid acting too late.
A draft of a forthcoming Intergovernmental Panel on Climate Change report that leaked earlier this year concludes that global temperatures are on track to rise in excess of 1.5 degrees Celsius above pre-industrial levels by about 2040. The 2015 Paris climate agreement set limiting global warming to 1.5 degrees Celsius as a sort of stretch goal, with the less ambitious target being 2 degrees Celsius. The IPCC report, which is expected to be released in October, says that even if the pledges made under the Paris agreement are fulfilled, warming will still exceed 1.5 degrees Celsius. The report also says that the differences between the present day and just 0.5 degrees more warming are “substantial increases in extremes,” including hot temperatures, “heavy precipitation events” and extreme droughts.
We don’t have to look to the future to see what climate change can do. At the EuroScience Open Forum, Camille Parmesan,1 a professor and member of IPCC, discussed her research showing that 90 percent of the 490 plant species examined at two sites, one in Washington, D.C., the other in Chinnor in the U.K., are responding to climate change in measurable ways. Some plants she’s studied require winter chilling to thrive, and that’s a problem, because winter is warming more than spring.
And temperatures aren’t rising uniformly. Areas at higher latitudes are warming faster than other places, and that has allowed outbreaks of infections from Vibrio, a bacteria genus that thrives in warm waters, to happen in places like the Baltic Sea area. “We’ve underestimated the impact of climate change thus far,” Parmesan said.
The accelerating consequences of climate disruption will be a major theme when COP24, the next iteration of the climate conference that produced the Paris agreement, meets in Poland in December. Another focus of discussion will be the progress that each country has made toward its “nationally determined contributions,” the voluntary goals for reducing emissions that nations set for themselves in Paris. Progress is not in line with these goals in many countries, Fabius said. “Germany is not fulfilling its [NDCs], and in France last year, CO2 emissions were up,” he said.
If decision-makers can’t agree on politics, they might be persuaded by economics, said Thomas Stocker, a climate scientist and a longtime member of IPCC. De-carbonizing our energy systems is “the biggest opportunity in the 21st century,” he told the EuroScience Open Forum.
Some local and state governments in the U.S. are exploring that opportunity. “The Trump White House is not just failing to do climate,” Parmesan said. “It’s doing its best to stop every advance we’ve made in the last 20 years, but what’s happening is a reaction from the ground level up that’s countering that national-level resistance.” (The White House did not respond to FiveThirtyEight’s request for comment.) As an example, she pointed to Georgetown, Texas, a city north of Austin. The electric company there is owned by the city, which has just switched to 100 percent renewable energy. “The mayor is quite conservative, and he got mad when people said it was for climate change,” she said. “He said, ‘No, no — it just makes economic sense.’”
Christie Aschwanden is FiveThirtyEight’s lead writer for science.