Source:
https://phys.org/news/2021-01-aerosol-particles-cool-climate-thought.html
"Clouds cool the climate system by reflecting incident sunlight.
The reflection of sunlight and cooling is stronger in the presence of pollution particles.
Pollution also affects the development of clouds: While increased pollution can deepen clouds by preventing them from being depleted by rain, the effect on non-raining clouds is uncertain.
Glassmeier et al. (2021) show that -- in contrast to traditional thinking -- the evaporation of non-raining clouds in polluted environments can reduce the cooling.
The impact of atmospheric aerosols on clouds and climate may be different than previously thought.
That is the conclusion of cloud researcher Franziska Glassmeier from TU Delft.
... Cloud decks cover vast stretches of the subtropical oceans.
They cool the planet because they reflect incoming sunlight back to space.
Air pollution in the form of aerosols—particles suspended in the atmosphere—can increase this cooling effect because it makes clouds brighter.
The cooling effect of pollution offsets part of the warming effect of greenhouse gases.
How much exactly, is one of the largest uncertainties faced by climate scientists.
... To figure out the climate effect of air pollution in general ... Glassmeier and her colleagues ... created an extensive data set of detailed cloud simulations.
At the heart of their study, the researchers designed a clever new way to compare their simulated cloud decks to satellite snapshots.
Such snapshots contain information about aerosol effects on clouds all over the globe, but have so far been hard to interpret.
... "To properly quantify these effects and get better climate projections, we need to improve the way clouds are represented in climate models," Glassmeier explains ... .
... There is still a lot to learn about how these tiny aerosol particles influence clouds and eventually climate." "