Unraveling the interconnections between air pollutants and climate change
In June 1991, Mount Pinatubo in the Philippines erupted for nine hours, ejecting volcanic ash, water vapor, and at least 15 to 20 million tons of noxious sulfur dioxide gas into the stratosphere. Within two hours, the gas ...
Although microscopically tiny, aerosol particles can have mighty impacts on the atmosphere and climate. Major volcanic eruptions and their resulting aerosol emissions high up in the atmosphere are infamous for altering monsoon circulations and precipitation patterns around the world, even triggering severe droughts in Eastern China and India.
Aerosols created by burning fossil fuels can also impact the climate, although the effects are somewhat different at the ground level. And as human civilizations attempt to reduce their emissions of these harmful particles, they are inadvertently generating unwelcome side effects, too.
Aerosols created by burning fossil fuels can also impact the climate, although the effects are somewhat different at the ground level. And as human civilizations attempt to reduce their emissions of these harmful particles, they are inadvertently generating unwelcome side effects, too.
Understanding aerosols
Ever since the first Earth Day was observed in 1970, the global average temperature has been accelerating at the rate of 1.7 degrees Celsius per century. Before 1970, the rate of warming was only 0.01 degrees C per century. At the current rate, the Intergovernmental Panel on Climate Change (IPCC) warned that the average global temperatures could rise by more than 2 degrees Celsius by 2100, which would unleash devastating impacts on the planet.
Ever since the first Earth Day was observed in 1970, the global average temperature has been accelerating at the rate of 1.7 degrees Celsius per century. Before 1970, the rate of warming was only 0.01 degrees C per century. At the current rate, the Intergovernmental Panel on Climate Change (IPCC) warned that the average global temperatures could rise by more than 2 degrees Celsius by 2100, which would unleash devastating impacts on the planet.
The eruption of Mt. Pinatubo in 1991 temporarily cooled the planet by half a degree Celsius, showing the power of tiny particles called aerosols. Credit: Dave Harlow, USGS
Air pollution hangs over a steel industry plant in 1973. Over time, the Clean Air Act dramatically reduced such harmful pollution — a big win for public health. However, with more sunlight reaching the Earth’s surface through cleaner air, global warming was exacerbated. Credit: John Alexandrowicz/U.S. National Archives and Records Administration
Extreme weather sensitivity to changes in greenhouse gases (left column) and aerosol removal (middle column). Projected effects on maximum daily temperature (TXx) are shown in the top row. Below that, maximum 5 day precipitation (RX5D) and consecutive dry days (CDD). Credit: Samset et al./Geophysical Research Letters, 2018