How do clouds affect the weather?

When clouds are fluffy and low to the ground they make the temperature cooler, but if they are high in the atmosphere they keep the Earth warmer. They do this in several ways, including absorbing the heat transmitted from the sun. How clouds affect the weather is likely to change because of global warming.

Clouds are able to mediate temperature in several ways:

• Clouds that are high up absorb heat from the sun's rays and radiate it towards the Earth.
• Clouds that are low down cool the Earth by blocking the sun's rays.
• They can both warm and cool the Earth by radiating heat from the surface towards space.
• When they form precipitation they provide water to the Earth's surface while drying the atmosphere.
• They alter the Earth's temperature with snow, rain and ice.
• When they trap temperatures from the Earth's surface and prevent them escaping into space they ensure they do not drop rapidly at night.
• When there are clouds at night it is warmer than when there are clear skies.

If greenhouse gases continue to raise the Earth's temperatures, the chances are cloud formations will change. However, scientists do not know whether this would result in cooler or warmer changes than usual on Earth. In addition, they do not know whether this would affect rainfall.