Russia’s ratification of the controversial Kyoto Protocol has renewed calls for U.S. officials to endorse the landmark climate treaty.

Ratification by Russia—one of more than 120 countries to endorse the treaty—means that the global climate agreement reached in Kyoto, Japan, in 1997 will come into effect early next year.

To become effective, the treaty had to be ratified by at least 55 industrialized nations accounting for at least 55 percent of global greenhouse gas emissions in 1990.

The U.S. emitted 36 percent of carbon dioxide emissions in the 1990—the most of any nation. But, the U.S. Senate overwhelmingly rejected the pact, and the Bush administration pulled out of the accord shortly after taking office in 2001.

Now, friends and foes of the United States are renewing calls for action. Even British Prime Minister Tony Blair—a key U.S. ally in Iraq—personally urged Bush to address the climate issue during a recent summit, and Blair plans to raise the issue during a meeting of the world’s eight largest economic powers early next year.

The United States is the only member of the G-8 that has not ratified the pact.

The U.S. “is the world’s biggest polluter and has a moral responsibility to reduce the pollution that is rapidly warming up the world,” said Tony Juniper, director of Friends of the Earth.

Juniper predicted that “international pressure” will grow for the Bush administration to “finally acknowledge the scale of the threat we now face and to take action to deal with it.”

The climate deal will take effect 90 days after Russia’s ratification. By 2012, industrialized nations must reduce emissions of greenhouse gases to 5.2 percent below the levels released in 1990.

Greenhouse gases make up only about 1 percent of the earth’s atmosphere, but they act like a blanket around the earth—trapping heat and keeping the planet about 30 degrees Celsius warmer than it would be otherwise. Human activities are making the blanket “thicker” —that is, naturally occurring greenhouse gases like carbon dioxide are being supplemented by emissions created by burning coal, oil and natural gas.

Scientists warn that atmospheric levels of carbon dioxide could double or even triple by the end of the century. As a result, average global temperatures could rise by as much as 6 degrees, according to scientists.

And that, in turn, could cause severe weather changes and rising sea levels, and dramatically change wildlife habitats. For example, scientists say that climate change is expected to alter the mixture of tree species in the Bay watershed, reducing the diversity of songbirds.

Another impact of climate change on the Chesapeake that could complicate restoration efforts is the sea level rise predicted for this region. At the same time, some efforts to combat global warming—such as curbs on fossil fuel emissions and incentives to create “carbon sinks” such as forests and certain types of crops—could bolster Bay cleanup goals.

Two studies released last month found that arctic temperatures were likely to increase twice as fast as global temperatures, melting ice floes used by polar bears, and that some butterflies and birds in North America have already begun to change their migration patterns in response to rising temperatures.

“U.S. ecosystems and wildlife are already responding to the warming climate,” said Eileen Claussen, president of the Pew Center on Climate Change. “And this is only the beginning. With warming for the next century projected to be two to 10 times greater than the last, we’re heading toward a fundamental and potentially irreversible disruption of the U.S. landscape and wildlife.”

The Kyoto Protocol places mandatory targets on greenhouse gas emissions for developed countries. Although the treaty would reduce overall emissions to 5.2 percent below 1990 levels, some nations must reduce their emissions more than others, and some nations are permitted to increase their emissions slightly.

The treaty also allows emissions trading—such as permitting greater emissions in exchange for the restoration of forests that act as “carbon sinks.” Countries that have emissions “to spare” can effectively sell credits to countries that exceed their emissions limits. A complicated “carbon market” has already been established in Europe.

The Bush administration has rejected the treaty, citing the impacts on the U.S. economy. In addition, administration officials said that treaty was flawed because it did not address emissions from fast-growing nations like China and India.

In the past, White House officials have also raised questions about the science underlying climate predictions, but officials have more recently conceded that an increase in heat-trapping gases was the most likely explanation for global warming. Nevertheless, the administration renewed its opposition to the treaty after Russia’s ratification, and instead favors voluntary measures to reduce emissions and the development on new technologies, such as hydrogen fuel cells.

“The United States is committed to working within the United Nations framework and elsewhere to develop an effective and science-based global approach to climate change that ensures continued economic growth and prosperity for our citizens and for citizens throughout the world,” said Rick Boucher, a spokesman for the State Department.

Whether the administration will accelerate efforts to address climate change seems unlikely, experts say. However, ratification of the treaty sets the stage for a new round of negotiations, to begin next year, over what happens after 2012.

“There is much about Kyoto’s design that is worth keeping, especially its use of market mechanisms to reduce emissions as cost-effectively as possible,” Claussen said. “But new approaches will be needed to better engage the United States and major developing countries in the international climate effort. Next year’s negotiations will be an important opportunity for all countries to think openly and creatively about a workable path beyond Kyoto.”

What’s clear, according to experts, is that states will adopt measures designed to reduce emissions regardless of who is in the White House.

Nearly 30 states have undertaken such efforts, according to the Pew Center on Global Climate Change. Four states—California, Connecticut, Massachusetts, and New York—have set standards for new cars that will require manufacturers to reduce greenhouse gas emissions by 30 percent by 2016. Colorado voters last month required large power companies to produce by 2015 at least 10 percent of the electricity from renewable energy sources like wind power.

“What’s happening to our environment is not natural it’s a problem of our own making. The longer we delay in reducing greenhouse gas emissions, the greater the problem will become,” Claussen said.