By David Ljunggren OTTAWA, April 25 (Reuters) - Canada aims to bring greenhouse gas emission 20 percent below current levels by 2020 under an environment plan to be unveiled this week, the government said on Wednesday. Environment Minister John Baird is to unveil his plan on Thursday. His speech on the issue was released ahead of time on a government Web site after a copy was inadvertently sent to an opposition legislator. Baird said Ottawa's plan would stop the rise in greenhouse gases in three to five years, and he promised to halve air pollution by 2015. "We find ourselves today with one of the worst environmental records among industrialized countries. Now, we need to turn things around," he said, blaming the previous Liberal government for inaction. "Once greenhouse gases have stopped rising, we will begin to reduce them, so that by 2020, Canada will have cut its greenhouse gas emissions by 150 million tonnes. This is 20 percent of our total emissions today." Baird also said Canada would explore domestic trading in emissions, whereby firms producing less greenhouse gas emissions than targeted could sell part of their allowance to firms that pollute too much. He said Canada would explore "future linkages with emissions trading systems in the U.S., and possibly Mexico. Our one test for any emissions trading system will be that it is first and foremost in the best interest of Canada". Critics complain the government is being too friendly toward heavy polluters such as the energy industry, which is based in the ruling Conservatives' power base in western Canada. They want Canada to stick to cuts mandated by the Kyoto Protocol on climate change. Leaked documents indicate Baird will opt for intensity-based targets that would reduce the rate at which companies and utilities pollute the atmosphere, rather than imposing firm targets for cuts. Baird said last week that firm targets would lead to a 25 percent jump in the jobless rate and a recession. "We will not spin the wheel so hard as to put the Canadian economy in the ditch to deliver (the) environmental plan asked for in some quarters," he said on Wednesday. Under the plan firms could meet their targets by: * cutting emissions * taking part in domestic emissions trading * participating in the Kyoto protocol's Clean Development Mechanism * investing in a technology fund designed to "help industry develop the solutions to produce deep reductions in greenhouse gases over time". Last October, Ottawa unveiled legislation that would cut emissions by between 45 percent and 60 percent from 2003 levels by 2050. The document leaked last week showed officials were proposing instead to cut emissions from 2006 levels instead. Baird's speech is available on the Environment Canada Web site at http://www.ec.gc.ca/default.asp?lang=En&n=6F2DE1CA-1&news=389E60E0-1E29-462A-B9AF-02A00CAC7AA9
