Annual Global Number of People Flooded under Three Emissions
Warm water takes up more space than
the same weight of cold water. As the earth grows warmer,
ocean waters expand, and the melting of glacial ice adds to
the rise in sea level.
When researchers use computer models to create scenarios about
how the climate might change and how this change will affect
people, they must make assumptions about human behavior. Different
assumptions give different results. In this graph, red represents
conditions if no efforts are made to reduce carbon dioxide
emissions. Blue represents stabilization of carbon dioxide
levels at 750 ppm (parts per million, or parts of carbon dioxide
per million parts of atmosphere sampled). That's almost three
times the pre-industrial concentration of about 280 ppm. Green
represents stabilization of carbon dioxide levels at 550 ppm.
Gray represents no climate change.
If no efforts are made to reduce carbon dioxide emissions,
researchers at the Hadley Centre for Climate Prediction and
Research estimate that sea level will rise by about 40 cm
(about 15 inches) by 2080. Notice that under all three scenarios,
the effect of sea level rise is different for each continent.
The effects of climate change will be felt differently in