Two centuries years ago, Voltaire proclaimed, “I disapprove of what you say, but will defend to the death your right to say it.” Today, our free speech traditions are under assault.

Colleges prohibit “offensive” or “politically incorrect” speech. Radical Islamists threaten to kill scholars, artists and even popes who “disrespect” the Prophet. And when we desperately need unfettered scientific debate, intolerant eco-activists have ushered in an era of climate McCarthyism and eco-Inquisitions.

Al Gore wants to muzzle anyone who raises inconvenient truths about climate alarmism. Greenpeace wants “climate criminals” pilloried and silenced. Grist magazine wants “Nuremberg-style war crimes trials” for climate disaster skeptics, followed by hanging, one assumes, since burning at the stake would release greenhouse gases.

Climate catastrophist Ross Gelbspan told a DC audience: “Not only do journalists not have a responsibility to report what skeptical scientists have to say about global warming. They have a responsibility NOT to report what those scientists say.” Reuters, Time, 60 Minutes and the Discovery Channel appear to have taken his views to heart. UK alarmist George Monbiot says the airlines contribute to climate change – so “every time someone dies as a result of floods in Bangladesh, an airline executive should be dragged out of his office and drowned.”

During a congressional hearing, Senator Barbara Boxer treated physician-scientist-author Michael Crichton like a child molester, for suggesting that claims about climate chaos should be reviewed by double-blind studies and evidentiary standards akin to what FDA uses for new drugs. And on October 27, Senators Olympia Snowe and Jay Rockefeller issued what the Wall Street Journal aptly called a “gag order” against ExxonMobil. “Its message: Start toeing the Senators’ line on climate change, or else,” said the Journal.

The Catholic Church’s dogmatic Earth-centered-universe theology has been replaced by an equally intolerant Church of Gaia catechism of cataclysm. But the problem goes well beyond that, well beyond constitutional rights and traditions of open, robust debate being trampled by newspapers and politicians duty-bound to uphold them.

It is, above all, an unprecedented power grab by activists, politicians and bureaucrats who want to be the final arbiters of every energy and economic decision.

Yes, Earth’s climate is changing – again, though far less than it has repeatedly throughout our planet’s history. Yes, people are influencing our weather and climate – to some degree. But few scientists have joined astronomer James Hansen in saying that humans have replaced the sun and other natural forces as the primary cause, Climate Armageddon is nigh, and drastic action must be taken immediately.

Cataclysm theorists point to computer models. But models are not evidence. Neither are headlines, hype or Hollywood special effects – nor incessant claims that every storm, drought, heat wave or cold snap is due to fossil fuels. Moreover, even perfect compliance with the Kyoto Protocol would do virtually nothing to stop hypothetical human-induced climate change. And the true costs of imposing Draconian measures would be astronomical.

Carbon taxes, carbon caps, greenhouse gas targets and timetables would send already high energy prices into the stratosphere, raise the cost of every consumer product and service, reduce profits, impair productivity, stifle innovation – and drive numerous jobs overseas, to countries where energy is still available and priced lower. Simply put, no juice – no jobs.

In the coming decade, according to energy analysts, Colorado alone will need 5,000 megawatts of new electrical generation; Texas, over 25,000; the USA, hundreds of thousands. Most will have to come from fossil fuels. Will policy makers enable or prevent us from meeting these needs?

If it takes 13,000 wind turbines (on 105,000 acres) to generate the electrical output of one 500-mW gas-fired power plant, how many turbines will it take to produce 50,000 mW? How much scenic acreage will they despoil? How many birds and bats will they kill?

If we emphasize intermittent, unreliable wind and solar power, will utility companies be reduced to promising they can ensure 12 hours of power a day, as we fire up assembly lines or head into surgery? If utilities have to sequester CO2 at $40-50 a ton, will they follow Britain’s lead, and tell parents who can no longer afford to heat their homes adequately: just send your children to bed with hats, mittens, sox – and bags of rice warmed in microwaves?

To reduce electricity demand, will Mr. Gore tell kids they can’t have Sony Playstations or computers? Will he seek a ban on plasma televisions, which use five times the electricity of conventional TVs? Will he stop flying all over the planet, to lecture lesser mortals about climate apocalypse?

Will the Senate Inquisitors – and their fear-mongering Greenpeace and NRDC shock troopers – now run their offices only on whatever electricity they can get from wind and solar power? What will they tell families of elderly folks who die in summer heat waves, because they can’t afford air conditioning – or AC has been banned as “polluting and unnecessary”?

How much will California really preserve our environment by having its future electricity generated by power plants sited in Montana, Idaho and Utah – and sent to LA via 2000-mile-long transmission lines – so that its legislators can claim to have reduced Golden State carbon emissions?

How many Third World families will remain impoverished and threatened with death from lung and intestinal diseases, because eco-imperialist agitators, politicians and bureaucrats continue to pressure banks and companies not to build power plants in poor countries?

These are just a few of the inconvenient questions and truths that alarmists want silenced. That’s why companies, legislators, scientists and citizens need to raise them, despite threats of Maoist show trials.

Raising these issues – and defending open, robust, civil debate about them – is the essence of ethics, social responsibility, citizenship, and now courage. Our forebears risked their lives to speak the truth. Surely we can risk a little public browbeating from Senate neo-McCarthyites, to ensure that our nation is not stampeded into enacting state and federal laws that will be economically and ethically disastrous.

We do not face looming climate chaos. We have time to respond rationally and responsibly, evaluate competing claims, demand real science and evidence, devise sensible laws and policies, and develop new energy generation technologies that will meet growing demand for abundant, reliable, affordable electricity – while improving efficiency, reducing pollution, and protecting the health and economic vitality of families, companies and communities.

Let’s hope the march toward totalitarian government ends, wisdom prevails, and we again place our faith in American optimism, creativity, innovation and true social responsibility.