This is a photograph of pollution over Beijing, China.
Click on image for full size
NASA image courtesy the MODIS Rapid Response Team
Aerosols and Climate Change
There are little particles in the atmosphere that are so small and light they can float in air. These particles are called aerosols. They may be small but they have the ability to change climate.
Some of them are natural. They come from erupting volcanoes, sea salt, and wildfires. Other aerosols are let loose in the air when fossil fuels like coal, oil, and gas are burned for energy. They are a part of air pollution, which is bad for people's health. They also lower the amount of global warming.
Aerosols in the atmosphere can change the amount of sunlight that is reflected away from Earth. Light colored particles reflect sunlight back out into space. Dark particles absorb most of the sunlight that hits them.
Aerosols help clouds form. The millions of little droplets of water that make up a cloud each need a little particle, like an aerosol, to condense upon. Clouds have an impact on climate. In general, clouds reflect incoming solar radiation back out to space.
Scientists think that over most of the last century overall effect of the added aerosols was a reduced amount of global warming. Now that we are making our air cleaner so that it is healthier for people to breath, the pace of warming will likely increase.
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