Clouds are accumulations of water droplets that usually form around very small particles, known as aerosols. These aerosols include desert dust, soot or compounds called sulphates.
|How the properties of clouds change in|
response to local pollution – mainly from
coal burning and ship engines – has
been more accurately determined.
Human activities can increase the local concentrations of these aerosols. For example, burning coal releases soot and sulphates, creating local hotspots of aerosols over power plants or cities.
Scientists know that these local hotspots of aerosols change the properties of clouds by providing them with more aerosols to form drops around, creating clouds with a greater number of smaller droplets than normal clouds. These clouds are also brighter than clouds not affected by pollution.
The brighter clouds reflect more of the incoming sunlight, providing a local cooling effect. This means that while human activities are warming the planet, through the release of greenhouse gases like carbon dioxide, they are also helping to cool parts of the planet, by releasing pollution aerosols.
Read the Science and Technology Research News story - “Clouds’ response to pollution clarified with new climate analysis.”