Philadelphia ? Your favorite TV show has ended. You’ve just seen the ads for Lipitor and light beer, and here comes another:

“Tick. Tick. Massive heat waves. One after another, the faces of small children appear.

Tick. Tick. Severe droughts. The kids look serious, maybe even upset.

Tick. Go to www.fightglobalwarming.com. While there’s still time.”

Yikes – did some ad exec get lost on a horror movie set? Not quite.

Fred Krupp, president of Environmental Defense, has teamed with the Ad Council, which has challenged social norms with public service campaigns like “Friends don’t let friends drive drunk” and Nancy Reagan’s “Just say no.”

In a series of TV and radio spots that one publicist termed “edgy” – and that a global warming skeptic called “the ultimate triumph of propaganda over science” – the group is hoping to spawn a massive shift in social awareness that will send millions rushing to turn down their thermostats, inflate their car tires and recycle their plastic.

The retaining walls in Shishamaref, Alaska, have crumbled because of rising sea waters due to climate change. Villagers who voted in 2002 to leave their ancestral home for the mainland are being called some of the first refugees of global warming. The Ad Council, in conjunction with Environmental Defense, is starting a campaign today to raise awareness of global warming.

All in an effort to reduce carbon emissions, which many scientists say contributes to global warming.

The first ads in what will be a multiyear campaign are going out to TV and radio stations nationwide today. As is the norm with public service ads, stations will run them at no cost, when they choose.

Krupp got the idea about a year ago. Struck by what he called a “cascade” of scientific evidence, he said he realized global warming is “the overwhelming environmental issue of our generation … Our children’s future is at stake.”

He called Peggy Conlon, president of the Ad Council, who was intrigued. A global warming ad campaign would be a first, she said. The council has done environmental campaigns before, including Smokey Bear and the Keep America Beautiful ad with the tearful, anti-littering Indian.

The council, which conducts public service ad campaigns with the help of volunteer agencies, stays away from politics. But it’s big on mobilization – for seat belts, for father involvement, for youth volunteerism, against crime.

Another of the new ads, all done by Ogilvy New York, shows a fragile plant growing near train tracks, then a speeding locomotive. A man appears. “Global warming,” he intones over the “chugga-chugga of the train. “Some say irreversible consequences are 30 years away. Thirty years? That won’t affect me.”

He walks off. But behind him – right in the path of the train! – is a little girl, blonde curls framing her puzzled frown.

The ads steer viewers and listeners to www.fightglobalwarming.com, which also debuts today and includes tips on how Americans can stick to a “low-carbon diet.”