If any doubt remains that global warming is occurring, one only has to check out the weather in Maine, Gov. King said Tuesday, a day after joining his counterparts from the other New England states and Eastern Canada in signing a plan to combat the warming trend.

This spring, the snow pack in the state’s mountains was the deepest ever recorded. Just a few months later, the state is experiencing one of the driest summers on record.

“I’ve been convinced,” King said by cellular phone during his return trip from the three-day New England governors and Eastern Canadian premiers meeting in Westbrook, Conn.

One effect of global warming is extremes in weather. That certainly is happening in Maine, the governor said.

Not everyone is so sure. President Bush remains a skeptic. In June, his administration withdrew U.S. support for the United Nations-negotiated Kyoto Protocol, a move that has drawn international criticism. The protocol sought reductions in the emissions of greenhouse gases, pollutants like carbon dioxide that trap the earth’s heat and hence alter the planet’s climate.

The president said he needed more information to determine whether global warming was occurring and that it was accelerated by human activity.

Later this summer, a National Academy of Science report requested by Bush concluded that the earth is warming and human activity has a large impact.

Now, Bush says global warming is a problem, but his administration has yet to decide how to tackle it.

Despite the fact that the federal government has backed away from an international treaty aimed at curbing global warming, the governors decided to press ahead with their own efforts.

The leaders signed on to a Climate Change Action Plan that lists a myriad of things that should be done to reduce greenhouse gas emissions. They range from urging people to buy more fuel efficient cars to reducing energy demands to encouraging the planting of native trees. All the measures are voluntary at this point.

The only specific goal in the plan is that the region reduce its greenhouse gas emissions to 1990 levels by 2010. The reductions would continue into the future until the threat to the climate is eliminated. The Kyoto Protocol called for reductions to 1990 levels by last year.

On Tuesday, environmentalists praised the governors for moving ahead.

“The governors have established a firm deadline for greenhouse gas emissions reductions, and, if they follow through, it will help to set us on the path to sustainable energy use and lowered air pollution,” said Adam Markham, executive director of Clean Air-Cool Planet, a New Hampshire-based group that seeks to halt global warming.

One reason the governors chose to move ahead with their own global warming plan, King said Tuesday, was to set an example for other states and the federal government. If the region hopes to exert pressure on its neighbors to reduce emissions, it needs to do the same itself, he said.

If nothing is done in Maine, greenhouse gas emissions are predicted to increase 30 percent by 2010, said Martha Kirkpatrick, commissioner of the Department of Environmental Protection.

She said the governors’ action was helpful because it would put pressure on Congress to toughen fuel efficiency standards and to initiate global warming legislation.

King said he would use his office as a bully pulpit to preach the message of energy conservation and fuel efficiency. But, he said, there is a tendency for people to assume that if there’s a problem, the government should solve it. In this case, individual actions, not government policies, will make the difference.

Since 60 percent of Maine’s carbon dioxide comes from cars and trucks, this will be the focus of the state’s efforts, King said.

Again, the state should set the example, King said. It would do this by adding a large number of fuel efficient cars to its motor pool. Currently, the state owns a few electric-gasoline powered cars.

Last year, the Legislature approved a program that would offer people up to $2,000 if they traded in old, high polluting cars for newer cleaner burning models. The program has been stalled for lack of money.

King said he did not think the government should be in the business of offering incentives. Instead, it should ensure that people have information about fuel efficient cars and offer improvements.

King also hopes to encourage people to think about where their power comes from. The state’s growing reliance on natural gas is troubling, he said, because if it continues, Maine will become too dependent on one source of power. Instead, people should think about alternative power sources, including wind and solar.

“Every ounce of oil we don’t burn, every kilowatt of electricity we don’t use, is a gain,” King said.

Consideration of alternative power sources is fine as long as people weigh all the possible harms, said Carroll Lee of Bangor Hydro Electric Co.

For example, many people oppose hydroelectric dams because they impede fish passage.

Proposals to put windmills atop mountains have been opposed because views would be obscured and birds could get caught in the turbines.

Many alternative energy sources also cost more than consumers are willing to pay, Lee said.