NEW YORK — Britain and Sweden are on target for reducing global-warming gases, but other countries will have to toughen policies and rely on "carbon trading" to achieve their Kyoto Protocol goals by 2012, says a new U.N. report.

In the United States, meanwhile, emissions of so-called greenhouse gases climbed by 16 percent between 1990 and 2004, the U.S. Environmental Protection Agency said in its latest assessment. The United States, by far the biggest emitter of carbon dioxide and other gases blamed for global warming, rejects the Kyoto pact on reductions.

Against this backdrop of rising emissions and discord over what to do about them, delegates from more than 160 nations on May 26 wrapped up two weeks of semiannual U.N. sessions in Bonn, Germany, on how to confront the threat of climate change.

On one track, they began talks on a stricter regime of emissions cuts for Kyoto nations after the 2012 expiration of that 1997 agreement, named for the Japanese city where it was negotiated.

On a second, less formal track, they began a "dialogue," including U.S. representatives, to try to draw Washington and other outsiders into the mandatory controls system.

"Both tracks got going in a fairly smooth way," Richard Kinley, chief U.N. organizer of the sessions, told The Associated Press. "It means there will be some very intensive talks in the next two, three years."

Scientists, meanwhile, are reporting mounting evidence of climate change:

--NASA satellite monitoring shows Greenland glaciers dumping water into the sea at twice the rate of 1996. Such melting land ice is helping raise sea levels, along with the expansion of seawater as it warms.

--The sea around the South Pacific island of Tonga has risen 4 inches (10 centimeters) in 13 years, according to the latest Australian measurements.

--Warmer water, followed by disease, has killed about one-third of coral reefs at official monitoring sites in the Caribbean since last year.

--Globally the year 2005 was either the warmest or second-warmest since record keeping began in the mid-19th century, according to NASA and the World Meteorological Organization. The warming is accelerating, boosting the mercury every decade by more than 0.3 degrees Fahrenheit (0.2 degrees Celsius), NASA says.

For more than a decade, a U.N.-organized network of scientists has warned of shifting climate zones, rising oceans and more extreme weather events if emissions of heat-trapping gases were not reined in.

The atmosphere today holds over one-third more carbon dioxide, byproduct of automobile engines, power plants and other fossil fuel-burning, than it did before the Industrial Revolution.

Kyoto, a protocol to the 1992 U.N. climate treaty, mandates controls in 35 industrialized countries that on average would reduce greenhouse emissions by 5 percent from their 1990 levels by 2012, with varying limits assigned to individual countries.

At this point, among 18 countries reporting, "only the United Kingdom and Sweden are projected to meet their individual Kyoto targets with current policies and measures," U.N. experts said in a progress report issued at the Bonn meeting.

Britain, benefiting from a switch from coal power plants to natural gas, projects it will reduce emissions by 19 percent by 2012, surpassing its Kyoto target of minus 12.5 percent. Sweden projects a 1 percent reduction, although it would have been allowed to increase emissions by 4 percent under the burden-sharing agreement adopted by the European Union to meet Kyoto's goals.

But such growing economies as Spain and Greece are projected to far overshoot their allowances. Canada, with a targeted reduction of 6 percent, says it is now emitting 30 percent more greenhouse gases than in 1990.

"Countries really have to think about introducing further measures to deal with their emissions," said the U.N.'s Kinley.

Some do plan more taxes and incentives to reduce fossil fuel use, the report notes. But the greatest progress may be made via the "Kyoto mechanisms," investment in clean-energy and similar projects in other countries.

For example, the Netherlands, which has a 2012 target of minus 6 percent but currently projects 1 percent growth instead, will get carbon-trading credits for a Dutch wind-power project in India that has just won U.N. approval.

There were 17 Kyoto countries that had not yet reported on their progress.

In Washington, the Bush administration says it will rely on industry's voluntary cutbacks and on government investment in clean-energy technologies to reduce emissions. In April, however, Government Accountability Office auditors reported that supposed voluntary cutbacks are being inadequately monitored.

On May 23, the Senate Foreign Relations Committee approved a resolution urging the administration to negotiate mandatory cutbacks. Its future in the full Senate is uncertain.

The White House objects that Kyoto-style mandates would badly crimp the U.S. economy, and complains that China, India and other poorer but fast-growing economies are not regulated by Kyoto.

Eliot Diringer, an analyst with Washington's private Pew Center on Global Climate Change, said China has signaled some willingness to join long-term efforts to limit warming. But environmentalists expect no change in the U.S. position before 2009 and the end of the Bush administration. Still, Diringer said, the talks begun in Bonn are important.

"It's important that people have a good understanding of the issues," he said, "so that when the political opportunity arises to actually negotiate a deal, they're in a position to do that."

Source: Associated Press