JIM LEHRER: A spokesman for President Bush made it clear today the U.S. was no longer interested in the Kyoto treaty on global warming. Spencer Michels has been looking into that debate, and here is his report.
SPENCER MICHELS: On the shores of California's Monterey Bay, a tide pool is revealing information about global warming that scientists here say bodes ill for the world's environment. The pool is just out the back door of Hopkins Marine Station. A few years ago, Rafe Sagarin, then a Stanford undergraduate working under Professor Chuck Baxter, used maps found in an old thesis from the library to find metal markers that had been pounded into the rocks about 70 years before.
RAFE SAGARIN: There were four originally, and we found two. One is out where those seals are, out there...
SPENCER MICHELS: The markers had been installed in the early '30s by Willis Hewatt, another Stanford student, who used them to intensely study a strip of tide pool one yard wide and 100 yards long. When Sagarin found Hewatt's Ph.D. thesis, he had a ready made baseline for examining the exact same designated area, or transect.
RAFE SAGARIN: It was really exciting, just the whole treasure hunt for finding the bolts that marked the transect, and it was very important because we were able to take a square-yard frame, which is exactly what Hewatt did, and put it down in the exact same place that he put down a square-yard frame, and compare that exact area to what happened now.
SPENCER MICHELS: Sagarin and his colleagues counted more than 125,000 tidal animals. With the average winter water temperature a degree higher than in Hewatt's day, he found that many of the old species had disappeared from this intertidal zone, and new ones had moved in.
RAFE SAGARIN: What we're seeing here is species that are really dominating the community, like this anemone, that have come from the south and are doing well here, really thriving.
CHUCK BAXTER: It has now become one of the dominant anemones in the intertidal, and it is a southern form, so it's one of the ones signifying change in the community.
SPENCER MICHELS: It's rare that scientists could quantify so accurately the effects of warmer weather. Sagarin says his conclusions go beyond the life in this tide pool.
RAFE SAGARIN: These animals are-- and plants-- are all sort of indicators that indeed, climate is changing, and it's having effects on living things. And we are still a natural species-- we depend on living things for everything-- so those effects are going to carry up all the way to the human realm.
SPENCER MICHELS: The director of the Hopkins Marine Station, George Somero, has watched the tide pool research, and his conclusions are even broader.
GEORGE SOMERO: Now, I see these changes that we're finding in marine communities as being a catastrophic situation. It's not effecting human beings yet to a very great extent. If it should turn out that the West Antarctic ice sheet begins to ebb, and as sea level rises, and if you are living on a coastal community, then the message may start coming across. And I think the intensity of storms that global warming is likely to trigger, again, is going to get a message across.
SPENCER MICHELS: Somero is at one end of a continuing debate over global warming and its effects on the earth. A vocal minority either doubts its existence, or says there is no reason to worry. But most mainstream scientists say its consequences could be serious.
They say global warming occurs because gases including carbon dioxide form a lid on the earth's atmosphere. That lid prevents some of the heat from escaping. Instead, it is reflected back to the earth's surface, where it raises temperatures. That's called the greenhouse effect.
At Kyoto, Japan, in 1997, delegates from all over the world agreed that all nations need to reduce their emissions of greenhouse gases, especially CO2. But no country has yet endorsed the rules agreed to at Kyoto. And three years later, a meeting at the Hague collapsed when participants couldn't agree on how to proceed.
SPOKESMAN: There's no deal. It's closed up.
SPENCER MICHELS: This year, a UN panel on climate change concluded that man-caused global warming not only exists, but threatens major changes in plant and animal life. Steve Schneider, an environmental scientist at Stanford, worked on the report.
STEPHEN SCHNEIDER: Not only do we think it's going to get warmer, and maybe unprecedentedly warmer, but we may change the incidence of extreme events-- that is, droughts and floods, heat waves, El Nino might intensify, and perhaps the most worrisome of all to me is increased intensity of hurricanes, because it's the top-end powerful storms that do most of the damage.
SPENCER MICHELS: Schneider and his colleagues say that one degree Fahrenheit of warming in the last century is pushing nature around. Glaciers are receding, lake and river ice is melting earlier, birds are migrating from the tropics sooner, marine communities are moving North along the California coast, and coral-- very sensitive to temperature change-- is dying, or bleaching, threatening to ruin the economies of areas that depend on it for tourism.
STEPHEN SCHNEIDER: So far, I would argue that we can't claim that's done any harm. But what it says is that even the one degree Fahrenheit is sufficient, now, to cause an impact on nature. And the projections for the future are, if we're lucky, a few degrees more, and if we're unlucky, ten. And ten, to me, would be certainly catastrophic for nature.
ANCHOR: When we strip away all the scare headlines and oversimplifications, a very different picture emerges.
SPENCER MICHELS: The Greening Earth Society, which made this film, is one of several industry groups that have not subscribed to the predictions of global warming catastrophes. The Western Fuels Association sponsors the society, which claims that more CO2 will benefit America, not harm it.
ANNOUNCER: Carbon dioxide is a plant nutrient that causes faster growth, increased yields, and improved water use efficiency, and this translates into more vigorous tree growth worldwide.
SPENCER MICHELS: President Bush joined the doubters when he recently decided not to press for a reduction in CO2 produced by American coal and natural gas power plants, reversing a campaign pledge.
PRESIDENT GEORGE W. BUSH: We got an energy crisis in America that we have to deal with in a common sense way.
SPENCER MICHELS: His turnabout followed intense pressure from the coal and utilities industries, which say reducing emissions would increase energy costs. In a letter to four Senators, the president said: "This is especially true given the incomplete state of scientific knowledge of the causes of and solutions to global climate change, and the lack of commercially available technologies for removing and storing carbon dioxide." The president's decision was applauded by Thomas Gale Moore, former economic advisor to Ronald Reagan, and now a senior fellow at the Hoover Institution.
THOMAS GALE MOORE: The evidence at the moment is that we have had a buildup of carbon dioxide, and that's leading to a greener world. We have more plants. In the northern hemisphere, they grow more vigorously, they grow faster, they're going further North. I would think that a greener world is a better world because we all either... all animals either eat plants or eat animals that eat plants, including us. So more plants is a good thing.
SPENCER MICHELS: More weeds?
THOMAS GALE MOORE: More weeds and more... and more redwoods.
SPENCER MICHELS: Moore, who wrote a book on global warming, says studies show it could even have positive economic effects in the United States.
THOMAS GALE MOORE: All the economists who have looked at it have concluded the effects are going to be minuscule for the United States. Trying to do something about it, however, they all agreed is going to be very costly. Let us take a little bit of the money that we'd spend on Kyoto and spend it on helping Bangladesh be able to protect them from sea surges which occur anyway, and help the people get rich. It's a much better way to go than this futile Kyoto.
SPENCER MICHELS: But Schneider says that the economic argument, even if it turns out to be partly true, is shortsighted.
STEPHEN SCHNEIDER: It's very likely that we'll be looking at increased endangerment, and probably quite a lot of extinctions. Now, if that's not into the economic calculations of those people who say it's good for you, all they're thinking about is corn plants and dollar return on investment. I think they're out of touch with the value system of most the people in the world.
RAFE SAGARIN: So I would kind of count a bunch of them at once.
SPENCER MICHELS: While the debate continues, so does the study of tide pools for additional evidence of changes due to warming.
RAFE SAGARIN: The intertidal animals are telling us something. And although I don't expect most people to care all that much that there's been a big species composition change in the intertidal, when it affects them and the health of their families, it is a serious issue.
SPENCER MICHELS: And yet more research is on the horizon. The Department of Energy recently announced it will join with the University of Maryland to look into climate change, ways to curb carbon dioxide emissions, and economic impacts of global warming.