Scientists from China and the USA have concluded that global warming is reducing the level of dust in the air in many parts of the planet. This dust reaches northern latitudes from tropical deserts. Dust greatly affects air quality. Moreover, it can be produced not only from local soil or emissions, but also by “flying in” from distant hot countries. For example, approximately 60 tonnes of sand from the Sahara enter Central Europe annually. The other day, a Mediterranean hurricane caused a sandstorm in northern Africa. This dust spread to Southeastern Europe with currents coming from the southwest.

But previous studies have shown that air dust levels are decreasing in certain parts of the planet, such as India and much of the Middle East. The reason for this remained unclear. Scientists from Hong Kong Baptist universities (China), Texas, California Institute of Technology (USA) and other scientific organizations tried to shed light on this issue. Their findings appear in the journal PNAS.

Analyzing satellite images over the last dozen years, researchers concluded that the number of microdust particles in India, Pakistan and other Asian countries has decreased significantly over the observation period. With the help of climate models, scientists also determined the cause of this phenomenon: a sharp warming in the Arctic, which is ahead of the rate of warming in other parts of the planet. Therefore, the temperature difference between high and low latitudes has decreased significantly. This disrupted the standard winds blowing in the desert regions of East Africa and West Asia. Wind speed in the countries of the Arabian Peninsula has decreased significantly, which has reduced the volume of sand microparticles lifted by the wind.

In addition, the authors of the paper noted that soil moisture and leaf area in Western Asia, from the Arabian Peninsula to India, also increased significantly. This made the soil there more compact, which also reduced the amount of dust in the atmosphere. Researchers link the increase in soil moisture and leaf area in the regions to anthropogenic carbon dioxide emissions (Naked Science has written repeatedly about this process, known as global greening).

The new study suggests that if the fight against anthropogenic CO2 emissions is successful, the level of dust in the atmosphere of the studied regions will rise again, causing serious harm to the health of local people.

It turns out that slowing global warming is a double-edged sword because it will lead to more dust in the air. This does not mean that we should continue to pollute the atmosphere, but in this case, according to scientists, we need to combat desertification, reforestation and control irrigation.