The Paradox That's Supercharging Climate Change

No good deed goes unpunished—and that includes trying to slow climate change. By cutting greenhouse gas emissions, humanity will spew out fewer planet-cooling aerosols—small particles of pollution that act like tiny umbrellas to bounce some of the sun’s energy back into space.

“Even more important than this direct reflection effect, they alter the properties of clouds,” says Øivind Hodnebrog, a climate researcher at the Center for International Climate Research in Oslo, Norway. “In essence, they make the clouds brighter, and the clouds reflect sunlight back into space.”

So as governments better regulate air quality and deploy renewable energy and electric vehicles, we’ll get less warming thanks to fewer insulating emissions going into the sky, but some additional warming because we’ve lost some reflective pollution. Hodnebrog's new research suggests that this aerosol effect has already contributed to a significant amount of heating.

The most important component in fossil fuel pollution is gaseous sulfur dioxide, which forms aerosols in the atmosphere that linger for mere days. So slashing pollution has an almost immediate effect, unlike with carbon dioxide, which lasts for centuries in the atmosphere.

It’s a gnarly, unavoidable catch-22, but in no way a reason to keep polluting willy-nilly. Fossil fuel aerosols kill millions of people a year by contributing to respiratory problems, cardiovascular diseases, and other health issues. So by decarbonizing we’ll improve both planetary and human health. The urgency is growing by the day: Last year was by far the hottest on record, and this March was the 10th month in a row to notch all-time highs. Meanwhile, ocean temperatures—boosted by El Niño, the warm band of water that periodically arises in the Pacific, which also added heat to the atmosphere—have soared to and maintained record highs for over a year, stunning scientists.

“The preponderance of those records and the margins by which they were broken was eye-opening,” says Jennifer Francis, senior scientist at the Woodwell Climate Research Center in Massachusetts. “Until society manages to stop increasing the greenhouse blanket, record-smashing events like those in