Serious pollution is slowing warming in major cities

The question of whether global warming is accelerating is the subject of heated debate among climate scientists. While some have argued that the current pace of warming, which reached an all-time high last year, is strictly correlated with rising fossil fuel emissions and therefore aligned with current climate models, others have warned that the Earth is much more sensitive to fossil fuels. than previously thought and that humanity is rushing towards turning points from which there is no return.

In a recent studyA group of researchers from the University of Melbourne complicated this debate with an analysis of warming rates around the world and possible causes of regional differences. His main discovery: the balloon is warming up at a faster rate, but this acceleration occurs unevenly. Surprisingly, densely populated areas with large concentrations of poverty (megacities like Cairo and Mumbai) are warming more slowly than the urban centers of Europe and North America. Because? The researchers found that the large amount of aerosol particles in the air of highly polluted cities reflects sunlight back into space and, at least in the short term, may have a net cooling effect on populations.

“It’s a puzzle,” said Edith de Guzmán, an adaptation policy specialist at the Luskin Center for Innovation at the University of California, Los Angeles, who praised the researchers for their work. The authors of the article emphasize that this finding should not be taken as a good sign. For one thing, it’s likely only temporary. And second, the protection, as it stands, only comes from harmful contaminants. De Guzmán agreed, saying that accelerated warming means that “populations that are already extremely vulnerable to a variety of environmental and climate injustices will become more vulnerable.”

As countries develop economically, their governments tend to adopt policies to clean up pollution, and as the air clears, vulnerable populations will be at high risk of dangerous heat exposure. Christopher Schwalm, director of the risks program at the Woodwell Climate Research Center, offered the example of China, where the government has begun to equip its coal-fired power plants with emissions reduction technologies such as scrubbers, to prevent soot from escaping the facilities. These measures are good for air quality, he said, but they will allow more heat from the sun to filter through. The most affected will be those who do not have access to air conditioners or shaded areas.

“The poorer you are, the hotter it is, and heat is a metaphor for all forms of climate disruption,” Schwalm said. “It is really difficult to do good without doing evil.”

Schwalm explained that the scientific community has about three dozen highly sophisticated climate models that are collectively considered a “panel of experts” on the trajectory of global warming. He believes that examining accelerated warming is useful because it can help countries plan climate adaptation measures and understand how realistic their current climate policy goals are (or are not).

Last year, the world exceeded the emissions targets of the 2015 Paris Agreementand is on track to do the same this year. Scientists are increasingly talking about the so-called death of the Paris Agreement’s commitment to keep the world below a temperature rise of 1.5 degrees Celsius (2.7 degrees Fahrenheit), in an attempt to force policymakers to deal with the inevitability of worsening heat waves and extreme weather. events to come.

The authors of the Melbourne paper offer much-needed insight into what that future will look like and how nations should prepare: their findings should encourage “specific climate adaptation strategies” aimed at the world’s poorest urban communities.

This article originally appeared in Grinding in https://grist.org/climate-energy/some-cities-are-so-polluted-they-re-warming-slower/. Grist is an independent, nonprofit media organization dedicated to telling stories about climate solutions and a just future. Get more information at Grist.org.