It's extremely frustrating to me to communicate over and over again, as clearly as I can.

And we are still, by far, the worst contributor to the problem.

And I look around and look for really meaningful signs that we're about to really change.

I don't see it right now.

A number of very reputable scientists have said that one factor of air pollution is oxides of nitrogen from decaying vegetation.

This is what causes the haze that gave the big Smoky Mountains their name.

Thank you very much, okay.

This guy is so far off in the environmental extreme, we'll be up to our neck in owls and out of work for every American.

This guy is crazy.

Even if humans were causing global warming, and we are not, this could be maybe the greatest hoax ever perpetrated on the American people.

We're dealing with something that's highly emotional.

If an issue is not on the tips of their constituents' tongues, it's easy for them to ignore it.

To say, "Well, we'll deal with that tomorrow."

So the same phenomena of changing all these patterns is also affecting the seasons.

Here is a study from the Netherlands.

The peak arrival date for migratory birds 25 years ago was April 25th, and their chicks hatched on June the 3rd.

Just at the time when the caterpillars were coming out.

Nature's plan.

But 20 years of warming later, the caterpillars peaked two weeks earlier, and the chicks tried to catch up with it, but they couldn't. And so, they're in trouble.

And there are millions of ecological niches that are affected by global warming in just this way.

This is the number of days with frost in Southern Switzerland over the last 100 years.

It has gone down rapidly. But now watch this.

This is the number of invasive exotic species that have rushed in to fill the new ecological niches that are opening up.

That's happening here in the United States, too.

You've heard of the pine beetle problem?

Those pine beetles used to be killed by the cold winters, but there are fewer days of frost,

and so the pine trees are being devastated.

This is part of 14 million acres of spruce trees in Alaska that have been killed by bark beetles. The exact same phenomenon.

There are cities that were founded because they were just above the mosquito line.

Nairobi is one, Harare is another. There are plenty of others.

Now the mosquitoes, with warming, are climbing to higher altitudes.

There are a lot of vectors for infectious diseases that are worrisome to us that are also expanding their range.

Not only mosquitoes, but all of these others as well.

And we've had 30 so-called new diseases that have emerged just in the last quarter century.

And a lot of them, like SARS, have caused tremendous problems.

The resistant forms of tuberculosis. There are others.

And there's been a re-emergence of some diseases that were once under control.

The avian flu, of course, quite a serious matter, as you know.

West Nile Virus.

It came to the eastern shore of Maryland in 1999.

Two years later, it was across the Mississippi.

And two years after that, it had spread across the continent.

But these are very troubling signs.

Coral reefs all over the world, because of global warming and other factors, are bleaching and they end up like this.

And all the fish species that depend on the coral reefs are also in jeopardy as a result.

Overall, species loss is now occurring at a rate 1,000 times greater than the natural background rate.

This brings me to the second canary in the coal mine.

Antarctica.

The largest mass of ice on the planet by far.

A friend of mine said in 1978,

"If you see the breakup of ice shelves along the Antarctic peninsula, watch out because that should be seen as an alarm bell for global warming."

And actually, if you look at the peninsula up close, every place where you see one of these green blotches here is an ice shelf larger than the state of Rhode Island that has broken up just in the last 15 to 20 years.

I want to focus on just one of them.

It's called Larsen B.

I want you to look at these black pools here.

It makes it seem almost as if we're looking through the ice to the ocean beneath. But that's an illusion.

This is melting water that forms in pools, and if you were flying over it in a helicopter, you'd see it's 700 feet tall.

They are so majestic, so massive.

In the distance are the mountains and just before the mountains is the shelf of the continent, there.

This is floating ice, and there's land-based ice on the down slope of those mountains.

From here to the mountains is about 20 to 25 miles.

Now they thought this would be stable for at least 100 years, even with global warming.

The scientists who study these ice shelves were absolutely astonished when they were looking at these images.

Starting on January 31, 2002 in a period of 35 days this ice shelf completely disappeared.

They could not figure out how in the world this happened so rapidly.

And they went back to try to figure out where they'd gone wrong.

And that's when they focused on those pools of melting water.

But even before they could figure out what had happened there, something else started going wrong.

When the floating sea-based ice cracked up, it no longer held back the ice on the land