Some scientists say global warming has already been going on for a while. Others say that we do not have enough information now to know for sure.
Despite the disagreements, most scientists are
convinced that greenhouse gases are warming the Earth. What they are still trying to figure out is how quickly temperatures are rising, and what will happen as a result.
The climate changes that will result from global warming are extremely difficult to predict. The weather is determined by so many factors that it is often compared to chaos by scientists. Changing the temperature will likely have
some effect on the planet's weather, but just what that effect will be is nearly impossible to predict.
If temperatures do indeed rise significantly, the most important result would be that some portion of the polar icecaps would melt, raising global sea levels.
The rise in sea levels would be disastrous for some places. Islands would disappear, meaning their millions of inhabitants would have to relocate.
Flooding would occur along coastlines all over the world, displacing more people and ruining cropland.
In the case of major global warming and melted ice caps, some countries might simply cease to exist. Global warming, if uncontrolled, could cause a major catastrophe.