If CO2 levels keep rising, global temperatures could soar, ice caps could melt, oceans could rise dozens of feet – and all that extra water pressure could destabilize Earth’s crust, squeeze out magma and cause volcanoes to erupt. The volcanic gases and dust could then cool the earth, and cause a new ice age.

A 1993 blockbuster movie used a similar what-if pyramid scheme to generate terrifying encounters with raptors and tyrannosaurs. But when the lights came up, people knew it was just a movie.

When it comes to climate change, however, many seem unable to separate science from science fiction – or even distinguish between headline-grabbing pronouncements, preposterous disaster flicks like “The Day After Tomorrow,” and pseudo-documentaries like “An Inconvenient Truth” and “The 11th Hour.” Instead of fostering rational discourse and responsible action, alarmists insist that we “do something” immediately to prevent climate cataclysm.

Al Gore is buying carbon offset indulgences. Leonardo DiCaprio is replacing his incandescent lightbulbs. Cheryl Crow promotes one square per trip to the ladies room. Cate Blanchett will wash her hair less often in her new $10-million Australian mansion. Cameron Diaz promotes “indigenous” lifestyles in Third World countries.

But they all support laws mandating greatly reduced energy use and economic growth – outside of Hollywood and Nashville’s Belle Meade area. In response, Congress has introduced a half-dozen “climate stabilization” bills – and state legislatures are reviewing 375 more – even as the scientific “consensus” fades, Europe’s united front on emissions trading collapses, and countries in the Asia-Pacific Partnership reject mandatory greenhouse gas cutbacks in favor of steady technological progress in pollution control and energy efficiency.

These bills would cost American consumers many billions of dollars a year. But they would reduce average global temperatures by a tiny fraction of the 0.2 degrees F that scientists say the Kyoto Protocol would accomplish by 2050 (assuming CO2 really is a primary cause of climate change).

It’s time to ask: At what point do symbolic gestures and political grandstanding become “doing something” about climate change? At what point do they amount to insanity?

Many suspect that anxiety about climate change was never really about preventing a global warming – or global cooling – catastrophe. Instead, they say, the real purpose is controlling energy use, economic growth and people’s lives. Alarmist efforts to intimidate climate catastrophe skeptics and legislate mandatory energy restrictions suggest that these suspicions are valid, and that climate doomsayers are becoming increasingly desperate.