Human life and health are intimately dependent on our climate, which is very much affected by small changes in temperature. Global warming and the resulting climate change are already having dramatic effects upon weather patterns, sea levels, agriculture and health.
Other, more sudden effects are also thought possible, but are harder to predict: these include large, rapid changes to the earth’s atmosphere as methane and carbon dioxide are released with the melting of permafrost; changes in ocean currents leading to rapid major changes in climate; and swift ocean acidification as dissolved CO2 levels increase.
We can also predict that there will be changes to our social systems, from loss of habitable land (including many areas that are now densely inhabited), greater incidence of illness, loss of food production, and failures in infrastructure under extreme weather conditions, landslides, etc.
Extreme weather, with more heat waves, desertification and drought in some areas, and more precipitation and flooding in others.
Sea-level rises of between half a meter and a meter during this century
Changes to ecological systems, including many extinctions and reduced ecodiversity
Just a few examples make the point that we cannot afford to ignore climate change and global warming, because the consequences of the changes which are already happening will, in turn, have huge, interlinked impacts on our general health, our societies, our living-spaces and our future opportunities as a species: