Reviewed by Mila PereraSep 22 2022
A global research group guided by Leipzig University has used satellite data to show that the accumulation of pollutant particles has reduced considerably since 2000.
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This is essential because of the effect on health, however, it has also decreased the climate-cooling effect of the particles. The findings of this study have been reported in the journal Atmospheric Chemistry and Physics.
Global warming is the result of greenhouse gas emissions. According to the Intergovernmental Panel on Climate Change (IPCC), the temperature had increased by 1.1 °C by 2019 compared to pre-industrial measurements.
Simultaneously, burning fossil fuels releases aerosols in the form of pollutant particles such as sulfuric acid or soot, which cool the climate. These aerosols reflect sunlight and also boost the clouds’ reflectivity.
According to the IPCC, aerosols in the air resulted in the climate being 0.5 °C cooler in 2019 than without them. Other effects like change in land use also have a role to play.
Study Documents Widespread Evidence of This Reduced Cooling Climate Effect
In a recent international investigation, Professor Johannes Quaas, a meteorologist at Leipzig University, and contemporaries from all over China, Europe, and the US have recorded strong proof of this effect on the climate of enhanced air quality.
We analyzed data from NASA’s Terra and Aqua satellites. They have been providing comprehensive satellite observations of the Earth since the year 2000, measuring incoming and outgoing radiation, but also clouds and aerosol pollution. The latter has decreased significantly across North America, Europe, and East Asia since 2000.
Johannes Quaas, Study Lead Author, Professor and Meteorologist, Leipzig University
This study commenced in a meeting by the two European research projects CONSTRAIN and FORCES.
Reduction in Aerosol-Induced Cooling Increases Warming Due to CO2 Since 2000 by up to 50%
This has also decreased the aerosols’ cooling effect. In contrast to the year 2000, it has resulted in a warming effect surge equal to 50% of the one increased by CO2 in the same time frame. This results in faster global warming.
Our study should not be interpreted to mean that we should now be emitting more aerosols to cool the climate. On the contrary: aerosols are harmful to human health and the environment, which is why we need to keep reducing emissions.
Johannes Quaas, Study Lead Author, Professor and Meteorologist, Leipzig University
This is the reason why air quality laws have become more and more rigorous since the 1970s and are being executed in progressively more countries. Professor Quaas and his contemporaries in the new study emphasize the ever more pressing need for quick and durable reductions in greenhouse gas emissions.
Journal Reference
Quaas, J., et al. (2022) Robust evidence for reversal in the aerosol effective climate forcing trend. Atmospheric Chemistry and Physics. doi.org/10.5194/acp-22-12221-2022