Dear Editor,

We hear people say, "I don't believe in global warming."

Global warming is well established in science. It is not a matter of belief, but of evidence, and the evidence for global warming is overwhelming.

Science is based on the preponderance of evidence, not isolated bits of data. Good science is published in peer-reviewed literature and must pass the test of further experimentation.

Some people accept that global warming is real, but deny that it is caused by human activities. These people are not entirely wrong; there are natural cycles of warmer and cooler eras.

However, the preponderance of evidence is that much of the warming we are observing is caused by the increase in the concentration of greenhouse gases, especially carbon dioxide, in Earth's atmosphere.

It is time to move on to the real issue: Is it too late to do anything about global warming? If not, what can we do about it?