Since calling global warming "the greatest scam in history [0]," the founder of The Weather Channel John Coleman has been an outspoken advocate for climate realism.

This weekend, Coleman posted [1] at his KUSI-San Diego blog an "Open Letter to Environmentalists" challenging them to campaign for "environmental goals on the basis of their own merit" while urging alarmists to "[l]et go of the global warming frenzy before it leaves [them] discredited and embarrassed."

Although readers are strongly encouraged to review the entire piece, here are some of the highlights:

• You have vigorously embraced the Global Warming predictions of the United Nation's Intergovernmental Panel on Climate Change and are using the warning of uncontrollable warming and a resulting environmental calamity to campaign for elimination of fossil fuels. Your environmentally conscious friends in politics and in the media have united with you to create a barrage of news reports, documentaries, TV feature reports, movies, books, concerts and protest events to build support for your goals. The war against fossil fuels has become a massive scare campaign that is giving children nightmares
• The science behind your global warming scare is bad and no anthropogenic global warming is happening. Dissenting scientists have now produced convincing evidence that the cornerstone of your scientific argument, increased atmospheric carbon dioxide forcing a rapid, irreversible rise in temperature, is invalid. All of the various "signs of global warming" you have so widely publicized have been proven wrong. They are normal variations in climate that result mostly from the cycles of the Sun. As the Sun cycle has changed in the last three or four years, they have reversed themselves.
• Campaign for your environmental goals on the basis of their own merit. Let go of the global warming frenzy before it leaves you discredited and embarrassed. Stop screaming, "The sky is falling." It is not.