Ever since international agreements to reduce acid rain in Europe were signed in 1980, a significant reduction of polluting particles in European air have contributed to a strong increase in the warming of the Arctic, according to new research.
Emissions of sulfur dioxide in Europe and North America peaked around 1980, and led to strict international agreements to reduce emissions.
Sulfur dioxide turns into sulfate when it comes into contact with air. The reduced content of sulphate aerosols in Europe from 1980 to 2005, may explain a significant part of warming in the Arctic over the same period, according to a new study published in Nature Geoscience.
Small polluting aerosol particles are carried into the air from sources including industrial and energy production, and can be transported very far downwind. For example, from Europe to the Arctic. High concentrations of aerosol particles causes acid rain and hazy air.
– Sulphate aerosols reflect solar radiation and helps ensure that there will be more, but smaller, droplets in clouds which then becomes whiter, says Trond Iversen, professor and climate researcher at the Norwegian Meteorological Institute and co-author of the study.
The greatest impact in the Arctic
– Aerosol helped to cool down the climate in the first decades after World War II, and thereby reduced the warming caused by increased emissions of greenhouse gases. All advanced climate models estimate that greenhouse gases provides the greatest amount of warming in the Arctic, and that the random Arctic climate variability is large. It is still surprising that sulfatpartiklers influence as strictly localized to Europe has the greatest effect on the climate in the Arctic, says Iversen.
Greenhouse gas emissions must be reduced
Scientists expect that the Arctic will continue to get warmer, because the concentration of greenhouse gases in the atmosphere continue to rise, while emissions of aerosol particles is probably going to decrease.
It will probably happen when you have to reduce local and regional air pollution problems elsewhere in the world.
Researchers from Stockholm University and the Meteorological Institute in Norway, stress that the new results show that it is important to rapidly reduce greenhouse gas emissions in order to mitigate climate change in the Arctic.
Source: NTB scanpix / Norway Today