My opinion about recent changes in the environment

In recent years we all have been hearing about global warming. It seems that the issue has been decided and we can’t do anything to stop it. Polar ice is shrinking at higher rate every year and environmentalists haven’t achieved any significant results in their fight against it.
But do we all agree that global warming is the thing to worry about? Does it have any certain negative effects or is it just a false impression of what is happening?