Preventing the worst effects of climate change will require conserving energy, protecting the coastline and cutting emissions of greenhouse gases, according to the report by the state Commission on Climate Change.

Using 2006 levels as a starting point, the commission said emissions of carbon dioxide and other gases that contribute to global warming should be cut by 25 to 50 percent by 2020 and 90 percent by 2050.

The commission listed those ideas among 42 recommendations in its long-awaited report, which was supposed to be completed in April. The recommendations are split between those aimed at preventing global climate change and those aimed at adapting to climate change.

"What this report is essentially doing is laying out a road map for the future of Maryland," said state environment Secretary Shari T. Wilson, who is chairman of the commission. "We're going to have to take a mix of short- and long-term actions."

According to the U.S. Environmental Protection Agency, climate change occurs when higher levels of gases such as carbon dioxide and methane are released into Earth's atmosphere. Those gases trap heat, instead of allowing it to dissipate into space - thus the nickname, "greenhouse effect."

In Maryland, greenhouse gases come from a variety of sources, but mostly from producing electricity and driving vehicles.

The result is increased air temperatures that can lead to rising sea levels and changes in the climate patterns around the globe. Research is ongoing to better predict those changes.

The commission's recommendations aren't much different from an interim set of recommendations released in December, though they are more detailed.

Some can be achieved through action within government agencies. For example, health officials can work on coping with heat-related illnesses during warmer summers. And local governments can make decisions on how intensely coastal areas can be built up.

But others require approval of state lawmakers. And members of the General Assembly already have shot down bills that would mandate the cuts in greenhouse gas emissions and set up a pollution credit trading system for companies and power plants that have large amounts of emissions.

Those efforts died in the face of strong opposition from the business community. Ms. Wilson said it hasn't yet been decided what legislation related to global warming will be pushed by Gov. Martin O'Malley's administration.

Opposition to cutting greenhouse gas emissions continues. An appendix to the report included letters from two manufacturers - the Sparrows Point steel plant in Baltimore County and Western Maryland's Redland Brick - raising concerns.

Redland Brick's Barry Miller said there's no way his plant can reduce carbon dioxide, which is emitted as part of the brick-making process.

"We do recognize that the issue of global warming is in vogue and we respect that so our interest is in finding a way to address it that will allow us to survive and hopefully grow as a business," he wrote.

The report argues that Maryland could actually could see a financial boost from so-called "green jobs" such as research into how to cut emissions and save energy. And consumers save money when they use energy-efficient appliances.

Cindy Schwartz of the Maryland League of Conservation Voters, who praised the report, said having a good economy and a good environment can go hand-in-hand.

"There's a nexus between these issues. If we are bold and we are brave, we can do the right thing for the environment, deal with global warming and have good new job production."

Ms. Wilson said Maryland already is making significant progress toward the 2020 goals. Efforts like joining a regional emissions reduction program and mandating more low-emissions cars will drop greenhouse gas emissions.

But more needs to be done, Ms. Wilson said, even in a small state like Maryland that admittedly is a small part of a global problem.

"It's very important that Maryland take action, as it's important that every state take action," she said.

Read the full report at www.mde.state.md.us/Air/climatechange.