* Photo: Yann Arthus-Bertrand/Altitude * The environmental movement has never been short on noble goals. Preserving wild spaces, cleaning up the oceans, protecting watersheds, neutralizing acid rain, saving endangered species — all laudable. But today, one ecological problem outweighs all others: global warming. Restoring the Everglades, protecting the Headwaters redwoods, or saving the Illinois mud turtle won't matter if climate change plunges the planet into chaos. It's high time for greens to unite around the urgent need to reduce emissions of greenhouse gases.

Just one problem. Winning the war on global warming requires slaughtering some of environmentalism's sacred cows. We can afford to ignore neither the carbon-free electricity supplied by nuclear energy nor the transformational potential of genetic engineering. We need to take advantage of the energy efficiencies offered by urban density. We must accept that the world's fastest-growing economies won't forgo a higher standard of living in the name of climate science — and that, on the way up, countries like India and China might actually help devise the solutions the planet so desperately needs.

Some will reject this approach as dangerously single-minded: The environment is threatened on many fronts, and all of them need attention. So argues Alex Steffen. That may be true, but global warming threatens to overwhelm any progress made on other issues. The planet is already heating up, and the point of no return may be only decades away. So combating greenhouse gases must be our top priority, even if that means embracing the unthinkable. Here, then, are 10 tenets of the new environmental apostasy.

ONLINE EXTRAS

How-To Wiki:

Use the Web to Reduce Your Carbon Footprint

How-To Wiki:

Build a Square Foot Garden

How-To Wiki:

How To Compost

How-To Wiki:

Tips for Green Lawn Care

Autopia:

Go Green — Buy A Used Car. It's Better Than A Hybrid

10 GREEN HERESIES

Live in Cities:

Urban Living Is Kinder to the Planet Than the Suburban Lifestyle

2 A/C Is OK:

Air-Conditioning Actually Emits Less C0 2 Than Heating

Organics Are Not the Answer:

Surprise! Conventional Agriculture Can Be Easier on the Planet

Farm the Forests:

Old-Growth Forests Can Actually Contribute to Global Warming

China Is the Solution:

The People's Republic Leads the Way in Alternative-Energy Hardware

__Accept Genetic Engineering: __

Superefficient Frankencrops Could Put a Real Dent in Greenhouse Gas Emissions

Carbon Trading Doesn't Work:

Carbon Credits Were a Great Idea, But the Benefits Are Illusory

Embrace Nuclear Power:

Face It. Nukes Are the Most Climate-Friendly Industrial-Scale Form of Energy

Used Cars — Not Hybrids:

Don't Buy That New Prius! Test-Drive a Used Car Instead

Prepare for the Worst:

Climate Change Is Inevitable. Get Used to It

COUNTERPOINT

It's Not Just Carbon Stupid:

The Danger of Focusing Solely on Climate Change