Global warming is a world problem and needs to be stopped.
Global warming may hit us hard no matter what we do.
Global warming is the most serious problem we face in the 21st century.
Global warming is also a big problem for them, because they are used to the cold.
He then looks at global warming in the next century.
Still, by the time he died, global warming had not become a major political issue.
President Bush has been feeling the heat on global warming.
Get back into the international effort to do something about global warming.
As they took a break, the team members were asked about global warming.
One of them being the possible effect on global warming.
