Participants in the Western Climate Initiative on Tuesday announced specific plans for cutting greenhouse-gas emissions 15 percent below 2005 levels by 2020. The seven states and four provinces will initiate a cap-and-trade program, establishing a carbon market that applies to industries and utilities by 2012 and transportation, heating, and other fuels by 2015. The proposed program is broader than that of the Northeast’s Regional Greenhouse Gas Initiative, which launches Thursday and only applies to power plants. But some aspects of WCI’s plan disappoint environmentalists: 90 percent of pollution permits can be given freely instead of auctioned, and companies can offset up to 49 percent of their emissions instead of actually eliminating them. WCI participants — Arizona, California, Montana, New Mexico, Oregon, Utah, Washington, British Columbia, Manitoba, Ontario, and Quebec — represent 20 percent of the U.S. economy and a whopping 73 percent of Canada’s, and are home to a total 84.6 million people.