Return to Transcripts main page

CNN LIVE EVENT/SPECIAL

Planet in Peril

Aired December 20, 2009 - 20:00   ET

THIS IS A RUSH TRANSCRIPT. THIS COPY MAY NOT BE IN ITS FINAL FORM AND MAY BE UPDATED.


(BEGIN VIDEOTAPE)

ANDERSON COOPER, CNN ANCHOR (voice-over): For every action, there is an equal and opposite reaction. It's one of the fundamental laws of physics, of nature. Nothing occurs in a vacuum in the natural world. There are ripple effects, and that is putting our PLANET IN PERIL.

This journey around the globe is an investigation into the reasons our planet is changing. It's about the front lines, the places where threats aren't just forecasts of the future, but are happening now. Where forests are lost.

UNIDENTIFIED MALE: We're destroying nature's natural regulator.

COOPER: Where islands are discovered.

UNIDENTIFIED MALE: This island exists because of global warming.

COOPER: Where water is poisoned.

UNIDENTIFIED MALE: A lot of people live around here and are dependent on this water.

COOPER: Where endangered animals are bought and sold and killed.

UNIDENTIFIED MALE: There's a lot of animals right here that range the gamut of critical status.

COOPER: Where people are dying.

UNIDENTIFIED MALE: We're hearing that people are getting cancer from drinking water.

COOPER: This is a planet under assault. This is a PLANET IN PERIL.

(END VIDEOTAPE)

COOPER: Tonight we begin in a place that's warming faster than just about any other place on earth. Greenland's ice sheet. Right now in Greenland it is eight degrees warmer than it was just about 10 years ago. Eight degrees.

Scientists say that is happening because of what we're putting into the air. Tons and tons of carbon dioxide. (BEGIN VIDEOTAPE)

COOPER (voice-over): The vast ice sheet of Greenland. Fifteen hundred miles long and more than a mile deep. The world's largest island. Eighty percent of it covered by ice. It's springtime here, though nothing is green.

This time of year the sun never sets. Just dips down to rest on the horizon. For almost at the top of the world.

But to really see what's happening here, you need to get on the ground. The ice is melting fast, and this island is warming.

JEFF CORWIN, BIOLOGIST: It's like nothing my eyes have ever experienced.

COOPER (on camera): It's also surreal. I mean as you look out at the horizon.

(Voice-over): Biologist Jeff Corwin and I have come here to find out why and see what impact Greenland's melting ice sheet could have on all of us in the decades ahead.

DR. CONRAD STEFFEN, UNIVERSITY OF COLORADO: We have never seen temperature rise in Greenland that's drastic over a short period. It's only about eight years.

COOPER (on camera): So how far have we come?

STEFFEN: We actually drove 11 miles.

COOPER (voice-over): Dr. Conrad Steffen of the University of Colorado has spent 17 seasons here, 300 miles north of the Arctic Circle.

(On camera): What are these rotating things?

STEFFEN: We have several sensors at different levels. These small planes, they measure the wind velocity.

COOPER (voice-over): He records the changing ice sheet through a network of monitoring and GPS stations. He's taking us to see and actually climb into a part of the landscape that's giving scientists important clues about why the ice is melting so fast.

The earth's climate has changed much during the planet's history. There have been ice ages and long periods of warmer temperatures. But scientists say our burning of fossil fuels like coal and oil has caused a greater concentration of heat trapping greenhouse gases in our atmosphere.

This buildup of gases prevents heat from escaping to space, acting like the panels of a greenhouse, warming the entire planet. Arctic temperatures are rising faster than anywhere else on earth. Why? As the atmosphere warms, the ice here melts and breaks apart, exposing water. That water absorbs the sun's heat and causes more ice to melt. Scientists call it a positive feedback loop. And it's causing Greenland's ice to disappear. Satellite data collected by NASA scientists in 2006 revealed Greenland is losing 100 billion tons of ice each year.

Ice does accumulate in the interior. But more ice is breaking off and melting at the edges. It's that imbalance which concerns scientists the most. If the entire ice sheet dissolved, sea levels would rise by 23 feet. Spurning a global catastrophe that would flood coastal cities and displace tens of millions of people.

Scientists don't think the entire ice sheet can melt any time soon. But every inch of sea level rise counts. Millions live near coastlines less than three feet above sea level.

(On camera): You've been coming here since 1990.

STEFFEN: We actually started in 1990. We came here not with the idea to monitor the abrupt change we currently observe. And the first two, three years were actually colder than normal. And then '94, '95 we started to warm steadily.

And since then, we actually have a temperature increase during the winter months of about 4.5 degrees centigrade, which is a very large temperature increase.

COOPER: 4.5 degrees, that's enormous.

STEFFEN: That's one of the largest temperature increases we have on earth.

COOPER (voice-over): 4.5 degrees Celsius is 8 degrees Fahrenheit. And here on the ice sheet you can see the impact that temperature increase is having. It's creating rivers of melt water that carve deep holes in the ice called mulans.

(On camera): So this is a mulan?

STEFFEN: Yes. This is a mulan. You can see the water channel coming all the way down. So let's explore it further.

COOPER (voice-over): As more ice melts, more of the mulans appear. We gear up to repel ourselves down inside. Hurling yourself backwards over a 15-foot cliff does take some practice.

CORWIN: It's easy. Just let yourself fall down, Anderson.

COOPER (on camera): Lean back.

CORWIN: Lean back and feel it. And remember, if you want to brake, pull the rope up towards you.

STEFFEN: Lean back.

COOPER: What the (EXPLETIVE DELETED). CORWIN: You've got to lean back. Step up. Step up. Step up.

COOPER: Perfect, yes!

CORWIN: So now you feed the rope. Then we can slide down like this.

COOPER: That was far more unpleasant than it needed to be.

(LAUGHTER)

So right now obviously there's snow here. But this could go much deeper.

STEFFEN: Yes. Usually these channels are up to 20, 30, 40 feet deep.

COOPER: So in the summer months ahead, as the temperature increases, water will actually start flowing through here.

STEFFEN: Oh, yes, definitely. If the water is so fast and has energy to actually carve into the ice before it drops into the water.

COOPER (voice-over): Last year Conrad and his team actually lowered a camera inside, a mulan capturing the first video from deep inside this icy tunnel.

(On camera): And what is the big picture? What's the significance of a mulan?

STEFFEN: They actually can reach through the ice, the ice sheet, and it can reach the bottom of the ice. Once this mulan fills with water and water is heavier than ice, it's possible then to lift up the ice. And then it's a labyrinth underneath the ice. And that's what you see, the ice moves faster.

CORWIN: So basically it's providing this layer of viscosity for the ice to slide on.

COOPER: So because of the research you've been doing here, what is it that alarms you in terms of climate change?

STEFFEN: First of all, it got much warmer than we expected. So the melt season got much larger. If you look at the latest reports put together by all scientists that discuss the climate change, they estimate the sea level will rise by 2100 to be about 50 centimeters, 1.5.

If you take that number, this is only based on melt. It's not based on the fast flow that generates the additional icebergs. By 2100 we'll be more likely one meter, 3 feet instead of 1.5.

COOPER: If the sea levels, by the models that we have now, are going to rise three feet in the next 100 years, can that be reversed at all? Can that be lessened? STEFFEN: Even if you reduce CO2 output at the current level and leave it level and declines, it will continue to warm. So even by stopping the increase of CO2 today means we will have a warming, we will have a sea level increase.

COOPER: Climate change isn't just having an impact here in the interior of Greenland. But you also see dramatic changes in the overall geography of the island. Particularly on the coastal areas.

We're going to travel to the east coast of Greenland where a new island has emerged because of the retreat of ice.

UNIDENTIFIED MALE: That's the island right there.

(END VIDEOTAPE)

(COMMERCIAL BREAK)

(BEGIN VIDEOTAPE)

COOPER (voice-over): From Greenland's interior ice sheet, we travel to its east coast with Dennis Schmidt.

(On camera): You expect to find other islands previously thought to be connected to the mainland?

DENNIS SCHMIDT, EXPLORER: Yes. There will be others. In fact, we know where they are. We're looking...

COOPER (voice-over): Schmidt is a modern day explorer. San Francisco is his home base, but Greenland is more like home.

SCHMIDT: This is a peninsula, a peninsula that's connected to the mainland because of an ice shelf.

COOPER: He's been coming here for more than 40 years. His explorations have led to discovery. I joined him to see his latest. One of the starkest examples of climate change.

It's not easy to land on a glacier. Especially one jutting out from a steep mountain. Our pilots make several passes. Scouting for a safe place. The co-pilot jumps out to test the snow pack. Finally, we put down. We are the first people to ever visit here.

SCHMIDT: No one has ever been here before. We're the first people.

COOPER (on camera): No one has ever been here, really?

SCHMIDT: Yes, we're the first ever to walk here.

COOPER (voice-over): We're here to see something extraordinary. Greenland's retreating ice has revealed a new island.

(On camera): In 2005, you came here. You were on a ship.

SCHMIDT: Yes.

COOPER: When did you realize, wait a minute, this is an island, this is not part of the mainland?

SCHMIDT: Yes. I sailed in to the peninsula. As we sailed into the base of it and we kept finding open water, I became disoriented. That was the beginning of the moment of discovery where I realized something was wrong. Either I was in a different place or the place where I was had completely changed.

And I pointed to the area of open water at the edge of the face of the glacier, and I said that's the world's newest island.

COOPER (voice-over): The world's newest island discovered because of the world's warming temperature.

(On camera): So how is this island an example of global warming?

SCHMIDT: This island exists because of global warming. This is a peninsula that became an island because the ice fields that connected it to the mainland of Greenland melted and structurally destabilized and broke away. So without the climate change, this would still be a peninsula.

COOPER: You have to be very careful when you're walking on a sheet of ice or a glacier in Greenland because there can be hidden crevices that open up. You can fall right through. That will be the end of you.

The thickness of the ice in Greenland has been changing over the last few decades. It's of great concern to scientists who are studying it. They found that in some spots, ice thickness has diminished by as much as 40 percent in the last 40 years.

SCHMIDT: That's what we want to look at now. We want to study this.

COOPER (voice-over): When you discover an island here, pending approval, you get to name it. Dennis chose the name Warming Island.

(On camera): That's a glacier over there. And these two glaciers used to be connected by an ice shelf.

SCHMIDT: They were continuous, yes.

COOPER (voice-over): Even the map of Greenland is changing.

After two days' exploring with Dennis Schmidt, we head back to the interior and Dr. Conrad Steffen.

STEFFEN: Hey. Hi, Anderson.

COOPER (on camera): Does it surprise you that new islands are cropping up in Greenland?

STEFFEN: No. I would not be surprised. Because we know the ice is retreating.

COOPER (voice-over): Dr. Steffen and his team live in a research station called Swiss Camp. They spend one month every year here living under extremely difficult circumstances. You have to see it to believe it.

(On camera): This is where you sleep?

STEFFEN: First, we slept in the station at the beginning. But during the cold years, we had some water that froze in the middle tent, which was our sleep tent. Which was not very comfortable. So we decided we go out into the tents outside.

COOPER (voice-over): In case you're wondering, there is a bathroom. Out here, it's an igloo. They call it the shigloo. The cold hasn't snapped their sense of humor.

What are these three? These are tents?

STEFFEN: Yes. This is actually Swiss Camp. This is our office where we have the electronic and computers. We also have a refrigerator. You're actually standing on our refrigerator.

(CROSSTALK)

COOPER: This is the refrigerator? Really?

STEFFEN: Yes. But it's filled with some fish and some steaks.

COOPER: Sounds good. So we go down the ladder here?

STEFFEN: Yes.

COOPER: All right.

STEFFEN: Be careful. It is rather steep.

UNIDENTIFIED MALE: How you doing, Connie?

STEFFEN: Good. Do you have some coffee?

UNIDENTIFIED MALE: No. It's not ready.

COOPER (voice-over): The makeshift kitchen where the dinner table doubles as a work space. Primitive, but they figured out how to keep the bread maker working.

STEFFEN: We have fresh bread every day. Watch your head here. Then we can go over to the work tent. This is our work tent, or as we call it, the computing room.

COOPER: In this small, cold space, Dr. Steffen and other scientists analyze the data they gather on the ice sheet. A stark finding that, for Dr. Steffen, raises a very basic question.

STEFFEN: The question is how can we actually change it for the future? We should not just think for ourself. We should think for the next two, three generation.

COOPER (on camera): As Dr. Steffen pointed out, climate change is something that's going to be affecting future generations. But it's also something that's having a major impact on people and animals right now.

Jeff Corwin's gone to track the North American's largest carnivore, the polar bear, to find out why some scientists believe the polar bear's very existence is under threat.

CORWIN (voice-over): Searching for polar bears in northeastern Alaska isn't like looking for a needle in a haystack. It's like looking for a haystack colored needle in a haystack.

(On camera): Incredible terrain of ice that seems to almost go on forever. Somewhere hidden on this ice, on this white reflected snow and ice, is a white creature that we need to catch up with.

(Voice-over): Steve Amstrup, a wildlife biologist with the U.S. Geological Survey, has been doing this for 26 years, trying to learn all he can about what polar bears can tell us about global warming.

STEVE AMSTRUP, WILDLIFE BIOLOGIST, U.S. GEOLOGICAL SURVEY: There's a nice lead that we might be able to pick up footprints on.

CORWIN: His eyes are keenly trained to find what seems impossible.

AMSTRUP: OK. See the tracks going across there?

CORWIN (on camera): OK. Oh, my goodness. Look at that. Yes.

AMSTRUP: See the one big set of tracks and two smaller tracks?

CORWIN: We got a family crew.

AMSTRUP: Yes.

CORWIN (voice-over): However, finding the tracks is only the beginning.

AMSTRUP: They did a 180-degree turn here. About 12 o'clock, led off the nose.

CORWIN: Our helicopter hugs the ground as we trace the footprints through the snowy expanse, over the rubbled ice. Until finally we spot them.

AMSTRUP: I see the tracks are going along there, up along -- and there's the bear, right there.

CORWIN (on camera): Oh, right there.

AMSTRUP: There's one (INAUDIBLE) right now. We have this (INAUDIBLE) and she's got some cubs alongside. And now we're going to move in and you're about to see something absolutely incredible. OK. Look at this. We're right on them.

CORWIN (voice-over): Amstrup loads the tranquilizer dart into the gun as we circle low over the mother bear to make sure we don't scare her away from her cubs. Then we lift up, and she takes off, racing across the ice. Our helicopter lowers down within feet of her. And Amstrup, hanging from the side of his window, aims and takes his shot.

(END VIDEOTAPE)

(COMMERCIAL BREAK)

(BEGIN VIDEOTAPE)

CORWIN (voice-over): We're on the heels of a mother polar bear and her two cubs. U.S. Geological Survey scientist Steve Amstrup loads his tranquilizer gun. Our helicopter lowers just over the running sow. Amstrup aims and then fires the dart.

AMSTRUP: Top of the shoulder. And now let get (INAUDIBLE) spot together.

CORWIN (on camera): Here's the plan. Steve got a beautiful shot. He landed that anesthetic dart right in the shoulder. We're going to give her some time to drop. It works rather quickly because we don't want mom and her cubs to separate so (INAUDIBLE) we'll physically capture these cubs and anesthetize them.

(Voice-over): That data is part of Amstrup's annual field study. He's exploring how a warming planet is impacting the polar bear. And what he's discovered is startling. Armed with a pistol just in case, Amstrup and I move in to secure the cubs. With the bears safely sedated, Amstrup gets to work.

AMSTRUP: This is the female cub. Polar bears are probably the most important symbol of the arctic from the standpoint of a measure of the health of the arctic eco system. Because they're entirely dependent on the surface of the sea ice for catching all of their food.

And the food that they eat, seals and other marine mammals, are entirely dependent on the eco system below them. So as the apex or top predator of the ecosystem, polar bears sort of integrate everything that's going on in the ecosystem underneath them.

CORWIN: Amstrup has been studying the polar bear for the past three decades. His data indicates an animal that's changing along with the habitat around it.

AMSTRUP: We're starting to see some changes that may result in future concerns for this population. We've seen declines in the survival of cubs. And we've seen adult males and cubs a little bit smaller in recent years than they used to be. And those are things that would be consistent with a population that might be under nutritional stress.

CORWIN: Under nutritional stress because it's simply getting harder for bears to eat.

(On camera): It's an impressive opening in the ice here. This is a lead. And of course, as you can see, we're not alone.

(Voice-over): A polar bear's primary source of prey are seals. They have the most success hunting seals in the 20- to 50-mile gap of water between coastline and ice. The water is more shallow there and the seals are more plentiful.

The problem is, though, just like in Greenland, that ice is melting.

AMSTRUP: When the ice melts in the summer, it used to be that it only withdrew from the Alaska coast a little ways. You know, maybe 10, 15 miles. Sometimes a little farther than that. But in recent years, we've had a gap of sometimes as much as 200 miles north of the Alaska coast.

CORWIN: As a result, biologists are now witnessing some very strange bear behavior. Some of these animals are actually drowning trying to swim these new open waters. Now, remember, these are marine mammals so they're not supposed to drown.

There are even cases of polar bears cannibalizing each other when the food runs short.

AMSTRUP: Ultimately, they're all dependent on the sea ice. And if the sea ice continues to decline as it has, it's going to affect polar bears.

CORWIN: The sea ice is melting. Melting faster than anyone expected. University of Colorado researchers say that in 2007, the Arctic Ocean lost one million square miles of sea ice. That's roughly six times the size of the state of California.

It is a record rate of decline. Sea ice loss has now surpassed predictions for the year 2050.

If the melt continues, Amstrup now thinks two-thirds of the world's polar bears will be gone in 50 years.

(On camera): So if the global population of polar bears somewhere between 20,000, 25,000 animals, why are we today trying to list them as endangered species?

AMSTRUP: The purpose of the proposal that the Fish and Wildlife Service has is not to list bears because of their present status, because of their present population, but because of their anticipated future status if the sea ice continues to change the way climate models project that it's likely to change.

CORWIN (voice-over): It would be the first time an animal has been protected because of global warming. It might be the only way to save an animal that, along with its habitat, could simply disappear.

(END VIDEOTAPE) CORWIN: To know that this charismatic and incredible life form could very well become extinct because its habitat is warming up and the ice it needs to survive is disappearing is really most profound. But the thing is, we've also learned that climate change is impacting total environments as well as the ice sheet on top of Greenland is very quickly melting away.

But beyond that, beyond the environment, beyond the impact on wildlife, human beings can be negatively impacted from climate change. And to truly understand that, we're now going to travel with Dr. Sanjay Gupta as he experienced how climate change is impacting people today in the South Pacific.

(BEGIN VIDEO CLIP)

DR. SANJAY GUPTA, CNN ANCHOR: We have been trying to get here for a few days now. It actually took five flights leaving from southern China. They say that the water is actually going to cover this entire island within a few years. What's going to happen to you?

(END VIDEO CLIP)

(COMMERCIAL BREAK)

(BEGIN VIDEOTAPE)

GUPTA (voice-over): Flying over the Solomon Sea in the South Pacific, the ocean and the sky melt together in a blue-green haze. We are 60 miles from any land. Only open water in every direction.

On the horizon, a small cluster of islands rise up from the sea. A long coral reef wrapping around them. These are the Carteret's Islands of Papua New Guinea. One of the most remote places on earth.

(On camera): We have been trying to get here for a few days now. It actually took five flights leaving from southern China and a helicopter ride which you just saw. We've come here to meet the people of Carteret.

The reason that we're here is because we hear that this island is sinking. And it's unclear exactly why. Some people say it's climate change. Some people say it's damage to the coral. Some say it's just sinking naturally because it was built on a volcano. Over the next few days we're going to figure out why and report that back to you.

GUPTA (voice-over): The five islands that make up the Carterets are just five feet above sea level at their highest point. The shoreline is steadily receding. Trees that once stood on the beach are now submerged. If the islands were uninhabited, it would simply be another mystery in the natural world.

Instead, tragically, 2,000 people live here, and they're literally being washed away.

This was their garden. The rising seas have washed it out. It's now a mosquito infested swamp. The swarms have brought with them malaria. It's now the number one killer here.

(On camera): Do you feel like the people here have been forgotten?

ROSE, ISLAND RESIDENT: They have been. Definitely.

GUPTA (voice-over): Rose has lived on the island with her family for 12 years. She says life here used to be good. Now, unable to grow their own food, they are dependent on supplies from the government of Papua New Guinea that come twice a year by boat from another island 60 miles away. Just twice a year.

ROSE: The supply that we have from the government which is how many bails of rice, it's already finished. And we are living on coconuts. Plus if we have the fish from the fish, then we have fish. If we don't we can live one day without food or two days without food.

GUPTA (on camera): That sounds pretty scary. It sounds like people are going to go very hungry, if not starve.

ROSE: Yes, I think so.

GUPTA: It looks like this upsets you.

ROSE: It does. It does. It does. It's even very hard.

GUPTA (voice-over): The people of the Carterets call themselves some of the world's first climate change refugees. What's happening here is a sobering glimpse into what scientists say the future will look like even if modest sea level rise predictions prove true. Tens of millions of people will have to be relocated.

That's exactly what's happening to the people of the Carterets. They're moving to yet another island. But many don't want to go. And it's easy to see why.

The island of Bugenville is a dangerous place. It suffered through a 10-year bloody civil war during the 1990s. Schools were closed for a decade. Thousands were killed. Crime and unemployment are high. The unrest and scars still visible today.

So for now, the people of the Carterets are left to wait and fight against the rising tides. But is climate change really responsible for what's washing away their world?

Like the earth's climate, the world's oceans have also warmed one degree Fahrenheit. When water heats up, it expands and rises. Scientists call it thermal expansion.

Global sea levels rose about 1.8 millimeters a year in the 20th century. But since 1993, an even higher sea level trend of 3.1 millimeters a year has been recorded.

While difficult to measure exactly how much, scientists believe part of the rise is due to melting glaciers and ice sheets like the ones we saw in Greenland. That melt is picking up steam, raising concerns for even more sea level rise, putting the Carteret's Islands and others like it in further jeopardy.

(On camera): You can see some of the trees here. I mean these actual trees, what happened? I mean did the water just knock them down?

BERNARD TUNAM, CARTERET'S ISLANDS CHIEF: The water just knocked them down. And in maybe two to three years this whole area will be just completely washed out.

GUPTA (voice-over): I met with one of the island's chiefs, Bernard Tunam. He was born here as were his parents and grandparents. He worries that he may not be able to stay much longer.

(On camera): Why is it happening?

TUNAM: Now because of the understanding of global warming, we believe that what is melting in the Arctic or the place where there is ice, and when that melts, the water is affecting us because the level of the sea is rising all the time.

GUPTA (voice-over): But it might not be that simple. What we saw from above the islands was a coral reef that appeared bleached and dying. Reefs serve as natural barriers to heavy storm surges that can swamp low-lying lands.

So is it rising seas or the loss of coral that's causing the Carterets to sink? When we come back, our investigation continues beneath the surface.

(END VIDEOTAPE)

(COMMERCIAL BREAK)

(BEGIN VIDEOTAPE)

GUPTA (voice-over): We're flying back to the Carteret's Islands in the South Pacific to try to solve the mystery. Why the islands here are disappearing. Is it rising sea levels? Or something else entirely? After two days here, there was only one place left to explore. Under water.

Chief Bernard takes us out by boat to the coral reef. He tells us we're the first journalists to dive the reef.

With dive gear and tanks, we head down, 60 feet. What we see is startling. A gray landscape with little marine life. Healthy coral reefs act as protective barriers to islands, helping slow destructive storm surges while providing food and shelter for marine life.

This reef is dying, which means less protection from storms and fewer fish to eat.

(On camera): So from the air we could look down at the coral and it certainly looked like a lot of it was dead. We actually just dove down. And when we got down there we saw evidence of what seemed to be bleaching. But actually an entire sheets of coral that seemed to be completely dead and washed out.

Now there was some evidence of live coral, but what's interesting is that some of that appeared to be dying in the process as well.

(Voice-over): Coral bleaching, scientists say, is a result of global warming. And it's happening in oceans around the world. Increased temperature and light caused the coral to expel the algae cells that live in their tissue. When the algae leave coral takes on the bleach coloring. Many coral reefs often die after bleaching.

And that, it seems, is what's happening to the Carteret's. Global warming might be causing a slight rise in sea levels. But its larger effect here is damage to the coral reef that protects these islands. Combine that with the fact that Carteret's sit on top an ancient volcano that overtime collapses inward and they could be sinking naturally as well.

But none of those reasons mean very much to Rose. Her home is disappearing. Her future is, at best, uncertain.

(On camera): I can see the water from here, Rose. And they say that the water is actually going to cover this entire island within a few years. What's going to happen to you?

ROSE: I will have to stay.

GUPTA: But it's sinking.

ROSE: No, it is definitely sinking. But the life here is too valuable to leave.

(END VIDEOTAPE)

GUPTA: We're going to take you next to a place that suffers not from too much water, but from not enough. Lake Chad. It used to be one of the largest lakes in the world, but it's disappearing.

(BEGIN VIDEOTAPE)

GUPTA (voice-over): It was once the sixth largest lake in the world. Covering more than 10,000 square miles. But over the past 40 years, Lake Chad in central Africa has shrunk by 90 percent. Where there was water, now only sand.

UNIDENTIFIED MALE: Here, we are suffering. Suffering from climate change. It's obvious here. We are fighting for survival.

GUPTA (on camera): We're here because we're told this is one of the most concrete examples of climate change anywhere in the world. People are dependent on their water. And they're not getting enough. Less water ultimately means fewer and smaller fish. And, as a result, the people are getting smaller as well.

(Voice-over): But the water crisis may be more than just climate change. We wondered, did something happen to the once mighty river that feeds Lake Chad? We decided to go there, try to get some answers along the way.

Lake Chad borders four different countries. Chad, Cameroon, Nigeria and Niger.

Our guide is Nada Tiega (ph), he's a native of Niger. He has seen the dramatic changes firsthand.

UNIDENTIFIED MALE: The struggle today is how to get food. People do not have enough food. Even if they have enough food in term of quantity, the quality is decreasing. And the diet of people is becoming less balanced.

GUPTA: As a wetlands manager, he spent the last four years working with the Lake Chad Basin Commission, a group that's trying to save the lake. There are roughly 37 million people who rely on Lake Chad. And they are quickly depleting what water is left. Much of it siphoned off to irrigate crops.

The lake has dried up before. Natural changes in the earth's orbit and the tilt of the sun 10,000 years ago caused the climate to shift, bringing out a long drought. But that's not what's happening today. The consensus among scientists is, something's different.

From the air, it's clear the lake is dropping.

(On camera): And this is what it looks like here on the ground. Sand, all around me. Look at this dry, cracked, parched earth. The water here used to be at least six feet high. And now, all around me, there's nothing.

I'm standing in Nigeria, what used to be the middle of Lake Chad. And believe it or not, this is the rainy season.

(Voice-over): And that, scientists say, is a direct result of climate change. As the earth gets warmer, moisture in the atmosphere that used to fall as rain instead evaporates. Water held in the soil and in lakes is also disappearing.

It's clear the weather patterns here have changed. The summer rains no longer able to replenish the lakes so many people have come to depend on. Climate change is making a bad situation worse.

Ironically, Africa is the lowest carbon emitter in the world. Yet, due to its dry climate, scientists say it's the most vulnerable to the effects of climate change. Combine that with the fact that Africa's population is growing faster than anywhere else in the world, the pressure on dwindling resources becomes clear.

We press on. And after two long days of driving in the sand, we're closing in on the source of Lake Chad. And hopefully to the answer as to why exactly it's disappearing.

It's 114 degrees in the desert when things take a turn for the worse.

When we come back, trying to break free from Africa's sinking sand.

(On camera): We're stranded. We're stranded as it turns out right now.

(END VIDEOTAPE)

(COMMERCIAL BREAK)

(BEGIN VIDEOTAPE)

COOPER (voice-over): Greenland's ice sheet. Forty percent of it gone in the past 40 years. Alaska's sea ice, melting and possibly threatening the future of the polar bear. The people of the Carteret Islands, literally being washed away. But is it a crisis or hype? What are we doing to our natural world?

(On camera): It's so disturbing to see this.

UNIDENTIFIED MALE: It's absolute, utter devastation.

COOPER (voice-over): What are we doing to ourselves?

GUPTA (voice-over): It's 114 degrees, and we're stuck in central Africa. We're trying to get to the source of Lake Chad to investigate why it's disappearing. So far, getting there is proving anything but easy. There are no winches out here to free our trucks. Just the bodies of our entire crew.

We finally break free as we close in on the Chary River. Lake Chad's source. We stop at a small fishing village called Duram Baga (ph) in Nigeria. It used to sit on the banks of Lake Chad. Over the past 30 years, the water has steadily receded.

(on camera): We're in a fishing community here. What's the impact on the people that live here?

UNIDENTIFIED MALE: Here the impact is really obvious. And here, as you can see, we don't have healthy fish. This species of fish can grow up to 60 kilograms, and today you see? They are just a few grams.

GUPTA: So this used to be up to 60 kilograms?

UNIDENTIFIED MALE: Yes.

GUPTA: And it's just a few grams now.

UNIDENTIFIED MALE: Yes. This means there is no health with them. So no healthy fish, so no healthy people. No food for people.

GUPTA: So are they getting sick or...

UNIDENTIFIED MALE: Yes. They are getting sick just because of food shortage.

GUPTA (voice-over): Some of the children here are clearly malnourished, and the poor diet makes all of them vulnerable to disease.

We continue our journey, a bumpy ride, for another few hours. Finally, we arrive at the Chari River.

(on camera): Here's one of the best examples of what's happening to the water over here. You're looking at River Chari there. This is one of the largest rivers that actually supplies water to Lake Chad. And that is Lake Chad. This used to be a mega-lake, one of the biggest lakes in the world. That's really all that's remaining of it now.

And right here, between that land over there and this land over here, this is the river mouth. That's all -- the water that supplies the lake is all coming through here. There's not very much left anymore, and that's what's happening to the lake. All this land is appearing and the water's disappearing.

(voice-over): Even the Chari River, the source for this once great lake, is evaporating. As Lake Chad disappears, many have nowhere else to go. The Lake Chad Basin Commission has a plan to divert water from the Congo River, but it remains controversial and unfunded. There are no easy solutions.

Heading back towards shore from Lake Chad, our journey here is coming to a close. What we found is that Lake Chad's disappearance isn't just climate change or simply overuse, but instead a combination of both, tens of millions of people competing for a resource that is literally evaporating. What's left is a daily struggle. But somehow, Anata (ph) holds out hope.

(on camera): You still are optimistic, despite everything that we've talked about today, that water is going to cover all this once again.

ANATA: Yes, it will. And as we heard from the fisherman himself, he said water will come. So everybody here keep hope.

GUPTA: From what we've seen in Greenland, Alaska and Africa, the earth's climate is clearly changing. It's not a theory, it's a fact. But what's causing those changes? The majority of the scientific community says it's mankind, but there are powerful voices who say otherwise.

SEN. JAMES INHOFE (R), OKLAHOMA: With all the hysteria, all the fear, all the phony science, could it be that man-made global warming is the greatest hoax ever perpetrated on the American people? I believe it is.

COOPER (voice-over): If you thought the debate over what's causing the earth to warm was settled, think again.

INHOFE: Sir, I don't want to be rude. But from now on, I'm going to ask...

COOPER: James Inhofe, Republican senator from Oklahoma, is the loudest voice with probably the biggest platform who questions whether man is responsible for climate change. His position has led to some intense political theater.

AL GORE, FORMER VICE PRESIDENT OF THE UNITED STATES: If I could complete my answer...

INHOFE: If you do, then my time's expired.

GORE: Well, I can't help that, because you went on for a long time. But I would like to...

INHOFE: No, I had 15 minutes.

GORE: I have...

INHOFE: You had 30 minutes. I had 15. You've got to let me...

COOPER: In 2007, scientists on the U.N.-sponsored Intergovernmental Panel on Climate Change concluded with 90 percent certainty that man is responsible for global warming. They were awarded a Nobel Prize for their work, but Inhofe questions the motives of those who say man's responsible for global warming.

INHOFE: This whole idea of global warming is something that has been brought up by certain groups who have a lot to benefit from it and it has nothing to do with real science.

COOPER: Nothing to do with science and everything to do with money. Support human-caused climate change, Inhofe's thinking goes, and you get more funding. But Inhofe's critics question his funding. The second biggest contributors to Inhofe's Senate office are energy and natural resource companies.

We wanted to talk to Senator Inhofe about those contributions and his position on climate change. But after agreeing to an interview with us, he canceled.

But the debate is not just political. Some scientists question the data and the models that predict climate change. Pat Michaels is one of them. He agreed to sit down with us.

(on camera): Do you think climate change is a hoax?

(COMMERCIAL BREAK)

COOPER (voice-over): The earth is warming. The ice sheets are melting. Lakes are evaporating. The question is why. Are human beings responsible? And even if we are, is it a crisis or just hype? Pat Michaels was Virginia's state climatologist for more than a decade and a professor at the University of Virginia. He's also a so-called climate change skeptic.

(on camera): Do you think climate change is a hoax?

PAT MICHAELS, SKEPTIC: Oh, heck no. Human beings are changing the climate. I think the warming that we're seeing is definitely at the low end of the projection range. COOPER (voice-over): A projection range based on computer models. That, he and other skeptics like him say, is a fundamental problem.

MICHAELS: The problem is, we have these things called computer models. And that's all we have for the future. And when we look at these computer models, one of the things we see is that they tend to predict more warming than is occurring.

COOPER: That's true. Some estimates do have the earth warming more than it currently is, and it's an illustration of the difficulty deciphering the debate. Both sides accuse each other of cherry picking data. Models you see also are underestimated our changing climate. Remember the sea ice you just saw in Alaska? Computer models had one million square miles of it melting by the year 2050, but that much ice had already melted by 2007.

Even so, not to fear, says Michaels. Animals like the polar bear and humans will simply adapt.

(on camera): The scientists who are warning of huge changes within our lifetime, are those just scare tactics?

MICHAELS: I think a lot of people have not looked at the adaptational responses that human beings have. Look at the United States, probably the most violent weather on earth of any large, civilized nation. The number of tornadoes is stunning. And big cities are in the way of these tornadoes. Death rates from tornadoes went down, down, down and down. Why? Adaptation.

COOPER (voice-over): Adaptations, he says, like stronger buildings, better warning systems. While a scientific consensus says man is responsible for global warming, Michaels, like Senator Inhofe, says money is the prime motivator.

MICHAELS: You write a proposal, you tie it to climate change, you've got a good chance.

DR. JAMES HANSEN, GODDARD INST. FOR SPACE STUDIES: You know, nothing could be further from the truth. And in fact, I'm a good example of that because when I first spoke out about this in 1981, I ended up losing my funding.

COOPER (voice-over): Dr. James Hansen doesn't believe scientists are simply chasing funding. Hansen, with NASA's Goddard Institute for Space Studies, was one of the first scientists to bring global warming into the public's consciousness in the 1980s.

HANSEN: We conclude that there is evidence that the greenhouse effect increases the likelihood of heat wave drought situations...

COOPER: Hansen was nearly alone back then. But today, he's brought the vast majority of the scientific community to his side. We are changing our climate, he says, and are risking a different planet. He rejects nearly all of the skeptics' points, from moderate estimates... HANSEN: We're talking about several meters of sea level rise if west Antarctica begins to go unstable.

COOPER: ... to computer modeling.

HANSEN: That's another big misconception. The computer models are helpful, but they are not the primary source of information. It's the earth's history that tells us with the most accuracy and the most reliability what the climate sensitivity is. We have measurements of the atmosphere composition very precise from the bubbles of air trapped in the ice sheets as a function of time over the last 700,000 years.

COOPER: Climate science is clearly complicated and often controversial. Both sides of the debate know that. For Jim Hansen, that makes the situation all the more pressing.

HANSEN: The nature of science is you say, On the one hand this, and on the other hand that. And even as the story becomes quite clear, we may not be making clear that we're really talking about a different planet. So I think we're running out of time. We've really got to get started in the next few years so that we're really on a different path.

COOPER: A different path because we're destroying much of what remains of the natural world, and these are vast resources we're losing. They feed us, provide us medicine and control our climate.

Jeff and I are now heading to Brazil's Amazon to see firsthand the battle for the world's greatest rain forest. You're looking at one of the largest emitters of greenhouse gases in the world, the Amazon rain forest. How is that possible? How is it that a forest covering nine countries, home to 250 indigenous tribes...

CORWIN: This is one of my most favorite creatures right here.

COOPER: ... holding one quarter of the world's species, can be a major contributor to climate change? Because it is, quite simply, under assault. The carbon naturally stored in trees is released when they're cut down, and they're being cut down at a breathtaking rate. These are the men bent on stopping that. They're agents with Ibama, the Brazilian government's environmental protection agency. This mission in a remote corner of Brazil has been in the works for over a year. The agents are heavily armed but heavily outnumbered. Their job is daunting, something you can only appreciate from the air.

CORWIN: Just in the Amazon basin alone, it's 2.7 billion square miles of habitat. And roughly 70 percent of that is right here in this extraordinary country, the country of Brazil.

COOPER (on camera): Two-point-seven billion square miles -- that's a little bit smaller than the continental United States.

CORWIN: Exactly. It's huge.

COOPER (voice-over): But all of that is in jeopardy. (on camera): It's so disturbing to see this.

CORWIN: It's just absolute, utter devastation and destruction.

COOPER (voice-over): Twenty percent of the jungle has been lost in the past 40 years.

(on camera): It seems, though, the problem is, once you get out to these remote areas, you can do just about anything. I mean, there are very few people watching over you.

CORWIN: These regions, when you're away from any bit of infrastructure, can be pretty lawless, and basically, anything goes.

COOPER (voice-over): Anything goes. And the Ibama agents know that. It doesn't take long for them to pick up one of the illegal roads made by poachers. There's no telling what's around each corner. In the distance, the agents spot something suspicious. The truck slows and guns are drawn. They've just found a truck with some people.

(COMMERCIAL BREAK)

COOPER: In a wooden shack in a remote corner of the Amazon forest, armed men pore over maps and make last minute plans. They're all here, more than 200 of them, to try and put a stop to the animal poachers and loggers who are tearing this forest apart. It's an effort led by Ibama, Brazil's environmental protection agency.

(on camera): These officers from the federal police are teaming up with Ibama agents. They're about to go out on patrol. For Ibama, secrecy is key. If word leaks out in this area that Ibama is here, that they're going to be on patrol and launching a series of raids, then the illegal loggers will simply disappear into the rain forest.

(voice-over): Officials say more than 1,000 people have died in the past 20 years in battles over the Amazon's resources.

Agents get word over the radio there might be an encampment of illegal loggers nearby, so they quickly pile into their trucks. Finding the roads made by the loggers is easy. What's not so easy is traveling them during the rainy season.

(on camera): These roads, as bumpy and terrible as they are -- what's even worse about them is that the roads are the conduit for the habitat loss.

CORWIN: Absolutely. This is basically the pathway for which the timber comes out.

COOPER: Illegally logged, for the most part.

CORWIN: Not all of it illegally logged, but a significant amount. Some statistics say that perhaps as much as 80 percent to as little as 60 percent is logged illegally. COOPER (voice-over): And that adds up. In 2006, 5,500 square miles of Amazon forest was cut down, roughly the size of the state of Connecticut, and that was a 25 percent decrease from the year before.

(on camera): It's politically correct to say you care about the rain forest, but why should someone actually care? I mean, if you're in New York or Iowa, what impact does the rain forest really have on your life?

CORWIN: Simply put, the survival of our species, of human beings, is directly dependent upon the survival of rain forest habitat. For example, 20 percent of the world's water is locked up in rain forest habitat, specifically the Amazon basin.

COOPER (voice-over): Despite its value, the destruction of this habitat continues. Brazil is the number one soy producer in the world, and it takes land to grow soy, land without trees. It's also the world's top beef exporter. Those two industries continue to expand, and they need land to do it.

But not all the trees are cut down for big profits. Some are harvested by small farmers eking out a meager living.

(on camera): Wherever you go in Brazil in the Amazon, you'll find that, fire. This is a small fire set by a man who's cutting down a couple of acres of land. This is classic slash-and-burn.

(voice-over): Cutting down and burning trees not only clears the land, it releases nutrients into the soil, making the ground more fertile. It's an easy but destructive way small-time farmers do business here. Like so many areas we've seen around the world, poverty plays a big role in habitat destruction.

(on camera): This is the front line of deforestation. Even though this land hasn't been cleared, it's going to be affected and the animals living on it are going to be affected by the fact that there are people living just a few feet away.

CORWIN: Very much so. At first glance, it looks like a relatively healthy forest. But just listen. What do you hear?

COOPER: Not much.

CORWIN: Not much. No birds. No buzzing insects.

COOPER (voice-over): The World Conservation Union says the Amazon is home to nearly 1,000 threatened species of plants and animals. Ibama doesn't have nearly enough personnel to protect them all.

Back on the muddy and rutted roads with Ibama, agents continue to comb the forest for anything that looks out of place. They may have just found it.

(on camera): Every day, Ibama agents go out on patrol and stop anyone they come across, question them about what they're doing in this biological preserve. They've just found a truck with some people. Let's check it out.

(voice-over): Their truck's broken down, and they say they need help. When agents find a hunting rifle, this man says they're only there to hunt one small animal. But his story doesn't add up and a quick search turns up a small arsenal.

(on camera): The guy has, like, what, one, two, three, four, five rifles.

CORWIN: He's got five rifles. He's got three machetes. He's even got a slingshot.

COOPER (voice-over): And a pack of hunting dogs.

CORWIN: These guys have all the classic tools of the trade when it comes to poaching wildlife.

COOPER: The men take us to their campsite, where they've already clear-cut the forest. Their cooler is stocked with deer meat poached from the rain forest.

CORWIN: Incredible. These gentlemen have been very, very busy.

COOPER (on camera): They said they were just out looking for a small animal just to eat. Clearly, it's a larger operation than that.

CORWIN: Clearly, their motivation was a bit more insidious. These animals they're hunting not just for themselves, they're probably selling the meat, as well.

COOPER (voice-over): The men are arrested and charged with possessing arms and hunting in the preserve, charges that could get them 10 years in jail.

(on camera): For Ibama these arrests are a sign of hope, one small victory in the ongoing battle to save the forest. These four men have been taken into custody. That means they won't be out hunting today, killing unfold numbers of wild animals.

Ibama has been fighting this fight for several years now, but it wasn't until 2005 when a 73-year-old American nun changed the way Brazil protects its forests.

(voice-over): In the small town of Anapu, deep in the Amazon state of Para, Sister Dorothy Stang is everywhere. Sister Dorothy came to Anapu from her native Ohio in 1983. She said she was drawn to the Amazon to work with the poor.

SISTER DOROTHY STANG: The only thing they know is survival farming. That's slash-and-burn.

COOPER: She started a sustainable development program, teaching locals how to live off the forest and at the same time preserving. Her mantra: The death of the forest is the end of our lives.

SISTER DOROTHY STANG: Bringing back new life to a land that was lost, it is possible. We can renew the forest.

UNIDENTIFIED MALE: Let's do it!

SISTER JANE DWYER, FRIEND OF SISTER DOROTHY: She may have looked like a little old lady to people from outside. But who live with her, she wasn't any little old lady. She was a powerhouse! But a decision -- you know, when she decided, she decided. And she would, you know, work to make it happen her way.

COOPER: But her friend and colleague, Jane Dwyer, says those tactics earned Sister Dorothy some powerful and dangerous enemies. Big ranching and logging companies were often in her sights. If they encroached on a peasant's land, Stang would report them to the government. As Sister Dorothy became more visible and successful, she started getting death threats. She refused, however, to be intimidated.

(on camera): On February 12th of 2005, Sister Dorothy Stang was walking down a secluded path in the Amazon jungle. Suddenly, she was confronted by two men. Words were exchanged, and one of the men took out a gun. Sister Stang didn't try to run away. Instead, she opened the Bible that she was carrying in her hand and read a passage from the Gospel of Matthew. "Blessed are they who hunger and thirst for justice, for they shall be satisfied."

As she closed the Bible and turned to go, the gunman opened fire.

(COMMERCIAL BREAK)

TOM FOREMAN, CNN CORRESPONDENT: Hello. I'm Tom Foreman, live from Washington.

Here's a look at some of our top stories at this hour. New York City is moving almost like normal after getting nearly a foot of snow. The Big Apple got off relatively easy.

Many places in the northeast received more than twice as much, setting one-day records. Airports are slowly getting back to service. And utility companies are hard at work in the Carolinas trying to get the lights back on for about 46,000 customers there.

One thing the massive storm did not slow down is the U.S. Senate, which is in session right now. Democrats are intensifying efforts to pass a health care reform bill before Christmas -- the first of several key votes is scheduled to take place about 3 1/2 hours from now at 1:00 a.m. Eastern. CNN will have live coverage of that vote. Join me and our chief medical correspondent, Dr. Sanjay Gupta, for our special at midnight Eastern. We'll look at what's in the bill, what's out, and what it could mean to you.

You can go to iReport.com and leave us your thoughts on this Senate bill on health care, what it might mean to you, and frankly, whether or not you even understand it. Share your thoughts and questions at iReport.com. We'll try to get to many of those on the air at midnight Eastern. Coverage you don't want to miss. Certainly important for all of us. I'm Tom Foreman. And I'll be back in a half hour with more newsroom. "CNN Presents: Planet in Peril" returns after this.

(COMMERCIAL BREAK)

(BEGIN VIDEOTAPE)

COOPER (voice-over): Early February 2005, Sister Dorothy Stang, an American nun from Ohio, leaves a meeting of peasant farmers whose land she's helping to protect and walks into the jungle towards her home. She never makes it there.

Two men met her on a muddy path. Words are exchanged. The men draw weapons.

But instead of running, Sister Dorothy opens the Bible she's carrying and reads them a passage. When she turns to go, they shoot her at point-blank range, leaving her in the mud to die.

Just days later, these two men confessed to the murder. Police take them back to the scene and they re-enact the brutal crime.

They tell police they were paid $25,000 by ranchers who wanted Sister Dorothy out of their way so they could continue illegally logging the rainforest. Four of the five men involved have been convicted in her murder. But the rancher who's believed to be the mastermind behind the plot remains free on bail.

But killing Sister Dorothy did not have the results some ranchers may have hoped for.

UNIDENTIFIED FEMALE: They thought that killing her would end it. Well, on the contrary, it did exactly the opposite. And the people are stronger than ever, and we do not intend to leave here.

COOPER: The Brazilian government responded by setting aside more than 30,000 square miles for protection. Sister Dorothy's death became a symbol, not only for the rainforest, but also for the protection of the people who call it home.

There are some 100,000 indigenous people living in Brazil's Amazon rainforest.

We've arranged to visit one small tribe, the Kraho Indians in the Tocantins state of Brazil. We're told by the chief it's a first time a helicopter has ever landed in the village.

(on camera): These are the Kraho. They're an indigenous people here in the Amazon rainforest. There's about 200 or so who live in this village. It's a protected reserve. We've just arrived here to find out how they're struggling to protect their habitat.

(CHANTING)

COOPER (voice-over): The Kraho always celebrate the arrival of visitors with a ceremony. (on camera): They're saying that very few people have come to this village, very few outsiders. So, to welcome us, they want to baptize us. That's the term they're using. They want us to -- they want to give us local names, names in their language, and also give us tribal markings.

(voice-over): They name Jeff "Running Deer."

UNIDENTIFIED MALE: Thank you. I'm honored by that. Thank you.

COOPER: And me, I'm "Regal Bird."

(on camera): Thank you very much. I'm very honored. Thank you.

After the festivities, we join the tribe for a meeting where they share grim news of what's happening to their home.

A tribal elder tells us they fight hard to protect their land and keep their traditions alive. But he says they're angry and scared by what's happening. There are about 3,000 Kraho Indians left in the Amazon basin, spread out in villages across 750,000 acres of protected land, given to them by the government.

But part of the Kraho's land has already been illegally clear- cut, and there's little to no law enforcement to stop it. Kraho are trying to take matters into their own hands.

(on camera): The Kraho are very concerned about illegal logging on their territory. Every day, they go out on patrol armed with bows and arrows, just making sure no one is cutting down trees.

(voice-over): They say they run off poachers on these patrols before, where their territory is huge and their numbers small. So the poachers keep coming back.

As hunters, gatherers and farmers the Kraho rely on the rainforest for food, water, shelter, everything. The Amazon is a vital resource for the world as well.

As Jeff mentioned earlier, the Amazon basin holds 20 percent of the world's water. At least 80 percent of the developed world's diet comes from the Amazon, mostly from the soy and beef industries; not to mention the tropical oils that are key ingredients in cosmetics like perfumes and shampoos.

It's a sort of natural medicine chest as well. The National Cancer Institute says, of the 3,000 plants that fight cancer cells, 70 percent of them are found in the Amazon rainforest.

But despite all of that, the rainforest is being pillaged at a rapid rate. Roughly 5,500 square miles are lost every year.

Back on patrol with the Kraho, we hike for hours through their territory but never find any illegal activity, at least not today. They will go out again tomorrow, however, trying to do whatever they can to stop their home and their way of life from disappearing. (END VIDEOTAPE)

COOPER: There's a pattern here. We see it not just with the Kraho, but also with others we've met, in Cambodia and China and Africa.

The disenfranchised usually bear the brunt of environmental degradation. And that doesn't just happen in remote corners of the globe. It's happening right here in America.

(BEGIN VIDEOTAPE)

COOPER (voice-over): For Valentin Marroquin, Manchester, Texas, seemed a fine place to grow up.

It was a tough neighborhood. But he had friends and plenty of places to play. His mother, Rosario, was just happy she found somewhere free from the violence and drugs that plagued other low- income neighborhoods. Her children were safe -- at least, that's what she thought.

ROSARIO MARROQUIN, MOTHER: My worst fear as a parent was losing my child somewhere, a park, crowded place. That's a parent's worst fear. You always think of something like that. You don't think your child coming down with cancer.

COOPER: At just 6 years old, her eldest child and only son, Valentine, was diagnosed with leukemia.

R. MARROQUIN: It's a numbing feeling. That's all I remember, just -- time stops.

COOPER: The very next day, Valentin began chemotherapy. Unable to protect her little boy, Rosario Marroquin felt helpless. She started looking for answers. She never could have guessed where she'd find them.

(END VIDEOTAPE)

(COMMERCIAL BREAK)

(BEGIN VIDEOTAPE)

COOPER (voice-over): Six-year-old Valentin Marroquin went from healthy one moment to a leukemia patient battling for his life the next.

R. MARROQUIN: He always said, "When I grow up, I'm going to do." He always said that, "Or I'm going to be chief of police," since he was little. Or "Mom, when I'm this age, and I want" -- and I would always think: is he going to get there?

COOPER: His mother, Rosario Marroquin, started searching for answers. And she kept coming back to their neighborhood and the stench that often envelopes it.

R. MARROQUIN: We have a stinky neighborhood. But we've gotten so used to it, that we don't know. That's just how we smell.

COOPER: The stinky neighborhood, because it sits next to the Houston Ship Channel, the largest petrochemical complex in America. Here, oil refineries, petrochemical companies, pump hazardous pollutants into the air.

A study released in 2006 show the concentration of known carcinogens, benzene and 1, 3-butadiene, was significantly higher, at least 20 times greater for 1, 3-butadiene than any other city in the U.S.

R. MARROQUIN: I'm not ignorant. Kids get sick in the country with fresh air. But this had something to do with it.

COOPER: Her suspicions were confirmed in 2007 when the University of Texas released a study showing children living within two miles of the ship channel have a 56 percent greater chance of getting leukemia -- a 56 percent greater chance.

While there's no clear-cut link, it's the first study showing an association between the ship channel's air quality and childhood leukemia. The risk is not just cancer. Benzene and butadiene are also known to cause other serious health effects, like respiratory diseases and birth defects.

So if we know all of this, why is it happening? For one thing: weak laws. And we'll go into that in a second.

"But the other reason," says environmental law professor Tom McGarity, "is because of race." Ninety percent of the people who live in the Marroquin's neighborhood are Hispanic.

TOM MCGARITY, LAW PROFESSOR: If these plants were emitting these kinds of levels in River Oaks, it wouldn't be happening. I promise. I can tell you that right now. River Oaks is the area where all the millionaires live.

COOPER: Activists call it environmental racism and say it's not just happening in Texas. Thailand, Cambodia, Madagascar, Chad, Brazil -- in each place, the poor and disenfranchised are usually the ones bearing environmental burdens. It happens there, and it happens here.

In 2005, "The Associated Press" found African-Americans are 79 percent more likely than whites to live in neighborhoods where industrial pollution is suspected of posing the greatest health danger.

MAJORA CARTER, SUSTAINABLE SOUTH BRONX: How do we improve the quality of life for everybody?

COOPER: Majora Carter is the founder of the Sustainable South Bronx, an organization that fights environmental racism in New York and around the country.

CARTER: Right now, race and class really determine where you find the good things like parks and trees, or where you'll find the bad stuff like waste facilities and power plants.

COOPER (on camera): The argument against your positions is an economic argument. Most often it's, well, look, it's cheaper to have plants in this neighborhood than it is anywhere else in this very expensive city. So...

CARTER: You think you're making the argument that it's better to have it up here because, you know, the real estate values are so low. It's about think about the other kind of costs associated with it that add up.

COOPER: Health costs.

CARTER: Yes.

COOPER: Crime.

CARTER: Yes. Somebody's paying for it. We all are.

COOPER (voice-over): But Carter points out the people whose health is in danger, whose quality of life is degraded, more often than not remain silent.

CARTER: I don't care if anybody in this neighborhood, like, never understands what global warming is. The point is there are people out there that are making decisions on our behalf that do and are deciding not to do anything about it.

COOPER: The Texas Commission for Environmental Quality chief toxicologist, Michael Honeycutt, disputes the idea.

MICHAEL HONEYCUTT, TEXAS COMMISSION FOR ENVIRONMENTAL QUALITY: One-third less pollution in the Houston Ship Channel this year compared to last year, because of our approach of bringing companies in, telling them what we want, and we're seeing those reductions. It's issues of timing. Scientists are generating data all the time. Something today -- you know, we find out today something is not as safe as we thought it was -- or, well, something is safer than we thought it was.

MAYOR BILL WHITE, HOUSTON, TEXAS: Nobody has the right to chemically alter the air that somebody else breathes without that person's consent. It's just not right.

COOPER: Houston Mayor Bill White has pledged to reduce the level of air toxins for those communities, even if it means playing hardball.

WHITE: We will have both a political and a legal battle with the industry until we get widespread agreement for them to do so.

COOPER: Tough talk. But here's something that might surprise you: when we talked to the companies in the ship channel, they've pointed out that they've started voluntarily limiting their emissions and they haven't broken any laws. And that's true. There's actually no law, no ambient air standards, either state or federal, requiring companies to limit the amount of hazardous air pollutants they pump out.

There is an effort under way to get a law passed in Texas, but Professor McGarity says it's going to be an uphill battle, because when it comes to the oil industry here, old habits die hard.

MCGARITY: That's going to be reflected at the top among the political appointees, who are more a part of this, shall we say, Wild West culture where anything goes.

COOPER: A Wild West culture where kids like Valentin Marroquin pay the price.

Now, 10 years old, Valentin is in remission and doing well. The Marroquins say they can't leave here because they can't afford it. They can't lock their children inside either.

R. MARROQUIN: When you're sitting out there, when you're watching them play, you're think, "Is it going to happen? Are they breathing it in now?"

COOPER: Valentin still loves his neighborhood and playing outside. He just has one request.

VALENTIN MARROQUIN, KID: To change the pollution for somewhere else. Somewhere no animals or no people live there.

(END VIDEOTAPE)

COOPER: Investigating our "Planet in Peril" has taken us to 13 countries on four continents. We've met literally hundreds of people along the way, some of whom you've been introduced to. Everywhere we've gone, we've been told the same thing. None of what's happening is occurring in a vacuum. In all these places, all these problems are interconnected.

When we come back, the lessons learned.

(COMMERCIAL BREAK)

COOPER: If you'd like to find out more information about the topics discussed tonight or find out what you can do to get involved, check out our "Impact Your World" Web site at CNN.com/Impact.

Everywhere we've gone, we've been told the same thing. None of what's happening is occurring in a vacuum. In all these places, all these problems are interconnected.

(BEGIN VIDEOTAPE)

COOPER (voice-over): In the Amazon along poachers' trails, in hidden villages, you can smell the smoke from the burning forests.

(on camera): From the air, you really get a sense of just how much of the rainforest has already been destroyed.

(voice-over): You can see the scars made by man. Plants and animals lost forever. Gases released warm the world.

The icy expanse of Greenland, land and sky seem frozen forever. The danger is hard to see with the naked eye. The ice melts, the seas will rise. How much? How fast? A matter of debate. But tens of millions will be affected in this century.

UNIDENTIFIED MALE: As the arctic changes under the effects of climate change and global warming, these very well could be one of the creatures most greatly affected.

COOPER: Already, polar bears' behavior is changing. Already, small islands slip beneath the sea.

UNIDENTIFIED MALE: They say that the water is actually going to cover this entire island. What's going to happen to you?

UNIDENTIFIED MALE: I will have to stay. The life here is too valuable to leave.

COOPER: More people are born, economies boom, we consume and grow more each passing year. By 2050, there will be 50 percent more people on the planet than there are right now.

In America, the discussion seems mired in politics -- skeptics, believers, liberals, conservatives. It all seems so theoretical -- environmentalism, the pet project of the rich, a cause for celebs.

But travel the world, and the issues are real.

UNIDENTIFIED MALE: The fact is that a minimum of 20 percent of all global emissions are coming from destruction of tropical forests.

COOPER: Struggles for land, fights over resources. People drink from polluted rivers in China and die in broken villages invisible from the gleaming towers of Beijing.

In Asia and Africa, animals and plants are ripped from the forests, species disappearing at 1,000 times the natural rate of extinction.

What should be done? What can be done? That's where the real debate is now.

We set out to report, not be advocates. No agenda. You've seen the front lines, the facts on the ground: overpopulation, deforestation, species lost, climate change.

Nothing happens in a vacuum. What happens in one place now affects us all.

(END VIDEOTAPE)