Britain’s Metrological Office scientists are pointing fingers to an unlikely villain in their effort to explain the mystery of tropical storms, that is, the quality of air.
Hurricanes in the North Atlantic regions are usually harsher and appear more frequently, and it may be correlated to the atmosphere’s lower levels of pollution. On the contrary, sulphate aerosols and factory chimney exhaust, vehicle exhaust, power stations, domestic fires, and economic progress by humans have played a significant part in keeping tropical storms at bay during the 20th century.
Nick Dunstone and his fellow climate scientist from the Met Office's Hadley Centre in Exeter, Devon reported in the Nature Geoscience paper, that there’s indirect connection that aerosols play a more vital role in the storm cycle that previously accepted.
The logic behind it is simple: when humans burn more fossil fuels, they emit greenhouse gases that make the planet warmer, and eventually the oceans. The atmosphere and oceans together make the climate system. Adding more energy, it should go somewhere. The resulting consequences, just like most scientists have thought, are the extreme weather changes.
Most of the 20th century however, humans have emitted greenhouse gases and other types of waste all at the same time, mainly sulphate aerosols and urban smog which caused the increase of acidity of falling rain, darkened buildings, damaged limestone structures, and damned hundreds and thousands of people to bronchial diseases.
The fact is that greenhouse gases like carbon dioxide can stay for up to 80 years in the atmosphere, while sulphate aerosols and soot will stay for only two weeks. Duncan and his colleagues used historical data to make out a pattern in storm behavior.
During the 20th century, aerosols actually suppressed hurricanes by cooling ocean waters. Although it was not possible to match specific storms with atmospheric levels of aerosol pollution, generally, it did seem like there were less tropical storms throughout the times where there were larger aerosol discharge.
The same conclusion is consistent with other modern research. Smog and other pollutants in the mid part of the 20th century were linked to drying up of Sahel and much of Lake Chad, and weakened the Indian monsoon.
