Aerosols and Global Heating
Aerosols are particles in the atmosphere that can be organic, like dust and water vapor, or inorganic, like VOCs and pollution from greenhouse gases. While Greenhouse gases like carbon, trap heat, other particulates from fossil fuels cool the planet by reflecting sunlight back into space.
As we start to phase out fossil fuels, the cooling effect we’ve had from some aerosols will disappear within a year, while heat trapping gases like carbon will linger in the atmosphere for hundreds of years and continue to heat the planet. This is another argument for a rapid phase out of fossil fuels because scientists don’t fully understand how much cooling aerosols have been giving us. Global warming is likely further along than we currently understand.
Read a roundup of the headlines:
“The findings, published on Wednesday in the journal NPJ Climate and Atmospheric Science, unveil a stark paradox at the heart of human-caused climate change.
It suggests that while cutting fossil fuel pollution is necessary for avoiding severe destruction over the long term — such cuts will make things noticeably worse in the short term…
But for all the damage they do to human lungs, aerosols also help shade the earth by scattering light particles from the sun that would otherwise warm the planet.
After the cuts, the study found that light reaching the surface increased by 7 percent…
A draft study led by Columbia University climate scientist James Hansen suggests that the recent rise in temperatures doesn’t come from greenhouse gases at all, but from the reduction in sulfate aerosols since the early-2000s.”
The Hill, Climate paradox: Emission cuts could ‘unmask’ deadly face of climate change, scientists warn
“Nonetheless, just three years after the international maritime community slashed sulfur emissions in 2020, the cloud physicist with Florida State University published an award-winning paper studying clouds along a shipping lane in the southeast Atlantic. By analyzing satellite data from before and after the regulation took effect, Diamond demonstrated that the clouds had dimmed. In other words, even as it cleaned its emissions, the global shipping sector made marine clouds a little less bright.
This change carries important implications for the planet. It means less sunlight is reflected back into space — which means more warming.
Aerosols, which are short-lived pollutants suspended in the atmosphere, introduce more uncertainty into climate models than any other variable. One of the most common comes from sulfur. Unlike its carbon cousin, sulfur dioxide tends to cool the planet by creating aerosols that reflect sunlight while also making clouds brighter. When industries around the world emit fewer of these pollutants, clouds darken. The planet absorbs more sunlight, and land, air, and water heat even faster than before.”
Grist, How cleaning up shipping cut pollution — and warmed the planet
“Summers and heatwaves in Europe will be even more sweltering than feared. The regional climate models relied on by planners greatly underestimate summer heat because they don’t factor in more intense sunshine due to falling air pollution, a study has shown.
“If models don’t take air pollution changes into account, they will underestimate the intensity of future heatwaves even more than they underestimate mean summer warming,” says Dominik Schumacher at ETH Zürich in Switzerland. “It’s problematic because a lot of European countries strongly rely on these simulations to plan for the future.”
New Scientist, European summers will be hotter than predicted because of cleaner air
“Atmospheric dust has increased by about 55% since the mid-1800s, an analysis suggests. And that increasing dust may have hidden up to 8% of warming from carbon emissions.
The analysis by atmospheric scientists and climate researchers in the US and Europe attempts to tally the varied, complex ways in which dust has affected global climate patterns, concluding that overall, it has worked to somewhat counteract the warming effects of greenhouse gasses. The study, published in Nature Reviews Earth and Environment, warns that current climate models fail to take into account the effect of atmospheric dust.
“We’ve been predicting for a long time that we’re headed toward a bad place when it comes to greenhouse warming,” said Jasper Kok, an atmospheric physicist at UCLA who led the research. “What this research shows is that so far, we’ve had the emergency brake on.’”
The Guardian, Atmospheric dust may have hidden true extent of global heating
“Climate change will become worse before it gets better.
According to research led by scientists at the University of Washington, eliminating greenhouse gases would stabilize the planet in the long term, but the subsequent loss of aerosols — small particles suspended in the atmosphere — could temporarily trigger alarming temperatures sooner than expected.
Aerosols come from natural sources — volcanic eruptions, for example — but can also be produced through the burning of fossil fuels and wood. They have a cooling effect on our atmosphere thanks to their ability to disperse sunlight and influence cloud formations.
The study published Monday says there’s a 42% chance the planet will reach 1.5 degrees Celsius of warming above preindustrial levels within the next decade even if worldwide emissions were eliminated today. If the world stopped emitting in 2029, that probability rises to 66%.
“If we were to reduce our emissions very rapidly, we lose that cooling effect of the aerosols much faster than we would lose the warming effect of CO2,” said Kyle Armour, a co-author of the report and an associate professor of oceanography and atmospheric sciences at the UW. “Because the aerosol pollution is currently masking some global warming that would otherwise occur, what that means it that at any given time, the Earth is committed to more warming than we’ve actually seen.”
The findings strongly suggest fossil fuels need to be phased out sooner than previously understood.’”
The Seattle Times, Aerosols from burning fossil fuels are masking global warming, UW researchers find
More Reading