Under the measure, an independent consultant would review efforts to cut carbon emissions in Washington state and elsewhere. A newly created work group of legislators and other leaders would use that evaluation to recommend actions to reduce pollution associated with climate change.
The group will be expected to prioritize strategies that are the most effective and provide the greatest environmental benefit for the money spent.
Supporters say the measure would help the state reach its target of reducing greenhouse gases. A 2008 state law called for Washington to return to 1990 emissions levels by 2020, and for reductions beyond that.
The Democratic governor, who signed the bill at The Bullitt Center in Seattle, has championed the issue of climate change as a key concern. He appeared before committees in the House and Senate to urge the bill's passage, saying that climate change threatens industries in the state and Washington is poised to take a lead in fighting global warming.
Environmental groups lauded the bill, which was sponsored by Sen. Kevin Ranker, D-Orcas Island.
"This law is an important first step toward reducing climate pollution in Washington," said Joan Crooks, Executive Director of Washington Environmental Council and co-chair of the Environmental Priorities Coalition.
Language in the original bill warned that Washington state is particularly vulnerable to a warming climate, and noted that greenhouse gas emissions from human activities posed a threat to public health and the environment.
But such language was removed in the Republican-controlled state Senate. House Democrats elected not to reintroduce that language, instead sending the bill to the governor for his signature.
Todd Myers, environmental director for the Washington Policy Center, said the measure marks an important change from past policies that he called "little more than symbolic gestures."
"With this legislation, Washington will begin prioritizing climate efforts based on environmental effectiveness, contributing to a cleaner world and making sure taxpayers get the environmental benefits they pay for," Myers said in a statement.
According to the latest numbers, published in 2010, about 101 million metric tons of carbon dioxide equivalent were emitted in Washington in 2008, about 2.3 percent less than in 2007 but about 9 percent more than in 1990.
Tuesday's measure won't be the first time the state has studied strategies to reduce greenhouse gas emissions.
Under former Democratic Gov. Chris Gregoire, the state came up with a plan in 2008 to reduce greenhouse gas emissions. The plan's centerpiece was a cap-and-trade program that would limit how much pollution large industries could emit as well as set up a regional market for polluters to buy or sell credits if they pollute more or less than their limit.
Gregoire aggressively pushed for and failed to get lawmakers in 2009 to approve a market-based carbon trading system, but later signed an executive order that same year aimed at reducing greenhouse gas emissions.
Among other things, it directed state agencies to work with large industries to find ways to cut emissions, and called for plans to be drawn up on how the state's largest counties can reduce the number of vehicles driven.