Scientists can use historic and current data to create a computer simulation of how the world's climateAverage weather conditions over longer periods and over large areas. may change in the future. This is called a climate model A computer simulation using historic and/or current data to predict how climate may change in the future..
Scientists created two climate models using data on carbon dioxide level increases:
due to natural sources only
due to both human activity and natural sources
The second model better matched the observed temperature changes.
This adds to the evidence that the observed warming of the Earth is because of human activities changing the composition of the atmosphereThe layers of gases that surround the Earth. The important gases in the atmosphere are nitrogen, oxygen and carbon dioxide..
Impacts of climate change
Scientists can also use computer models to predict the impacts of climate change.
What is affected
Impact
Ice
Melting of the Antarctic ice sheet and melting of glaciers in the Northern Hemisphere.
Sea levels
Likely to increase due to melted ice and expansion as temperatures increase.
Ocean temperature
An increase in ocean temperature could change ocean currents and the climate of countries bordering these currents (like the UK).
Extreme weather
Greater differences in weather, for example, more intense droughts and floods and more extreme temperatures (both hot and cold).
Impact on crops
Low lying farmland may be flooded. In areas where there is less rainfall droughts may make it difficult to grow crops. If there is extreme rainfall then crops could get flooded and washed away.
What is affected
Ice
Impact
Melting of the Antarctic ice sheet and melting of glaciers in the Northern Hemisphere.
What is affected
Sea levels
Impact
Likely to increase due to melted ice and expansion as temperatures increase.
What is affected
Ocean temperature
Impact
An increase in ocean temperature could change ocean currents and the climate of countries bordering these currents (like the UK).
What is affected
Extreme weather
Impact
Greater differences in weather, for example, more intense droughts and floods and more extreme temperatures (both hot and cold).
What is affected
Impact on crops
Impact
Low lying farmland may be flooded. In areas where there is less rainfall droughts may make it difficult to grow crops. If there is extreme rainfall then crops could get flooded and washed away.
