King County will try to boost its use of fuel made out of everything from soybeans to rotting garbage in the coming years, one of several measures County Executive Ron Sims announced Wednesday as part of a plan to cut the county's contribution to global warming.

Sims said county agencies will try to prepare for the possible impacts of global warming and to establish the county as a place to demonstrate ways governments can cut climate-altering gases such as carbon dioxide.

"What we've done is made King County a lab," Sims said.

Sims has ordered county employees to work toward using renewable sources for half of the energy used by county offices, cars and buses. He pledged to protect an additional 100,000 acres of county land by 2010. He said the county would reuse treated sewer water. And he said that future land-use plans would be made with an eye toward cutting people's dependence on cars.

The orders left a number of questions unanswered: How much will it all cost, how much the actions will reduce the climate-altering gases that the county produces, and how the county will actually protect that much land.

Sims said the county can afford the plans. And he said it will be less significant than the costs of not preparing for change.

Friday, Seattle Mayor Greg Nickels is planning to unveil a report recommending how the city of Seattle can comply with the Kyoto Protocol, an international pact calling for global reductions in the climate-altering, or greenhouse, gases.

Al Gore, former vice president and 2000 Democratic presidential nominee, is expected to appear with Nickels for the rollout.

Pete von Reichbauer, the Metropolitan King County Council's senior Republican, said he generally supports Sims' goals, including measures such as boosting the use of renewable fuels.

But he said he wants more details about other plans, such as Sims' land-protection pledge.

Warren Cornwall: 206-464-2311 or wcornwall@seattletimes.com