- Global warming is caused by the emission of greenhouse gases.
- They reflect sunlight and also increase the reflectivity of clouds.
- Other effects such as land use change also play a role.
Using satellite data, an international study team has shown that pollutant particle concentrations have dramatically dropped since the year 2000. This is preferred because of how they affect health. However, it is also very important because it has lessened the particles’ ability to chill the environment.
Primary cause
The release of greenhouse gases is the primary cause of global warming. In comparison to pre-industrial levels, the temperature had increased by 1.1 degrees Celsius by 2019, according to the Intergovernmental Panel on Climate Change (IPCC). However, the burning of fossil fuels also produces aerosols, which are pollutant particles like sulfuric acid or soot that cool our temperature. They improve the reflectivity of clouds and reflect sunlight. The IPCC estimates that in 2019 the climate was 0.5 degrees Celsius colder than it would have been absent aerosols from the atmosphere. Land use changes and other impacts also have an impact.
Reduced cooling climate effect
Professor Johannes Quaas, a meteorologist at Leipzig University, and colleagues from across Europe, China, and the US have now compiled strong evidence of this influence of improved air quality on climate in a new international investigation. “We examined information from the Terra and Aqua satellites of NASA. Since 2000, they have been giving detailed satellite views of the Earth, detecting not just clouds and aerosol pollution but also incoming and outgoing radiation. The latter has decreased significantly across North America, Europe and East Asia since 2000,” says Professor Johannes Quaas, lead author of the study, which was initiated 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%
As a result, aerosols’ cooling effect has diminished. It has resulted in an increase in the warming effect compared to the year 2000 that is up to 50% greater than the one caused by CO2 rises during the same time period. This means an acceleration of the drivers of global warming compared to the previous period. “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,” Quaas concludes. And that’s why more and more nations are implementing stricter air quality laws that have been in place since the 1970s. The latest analysis by Professor Quaas and his colleagues emphasises the growing urgency of swift and significant reductions in greenhouse gas emissions.
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Source: Science Daily
