AUGUSTA – The goal is simple – to cut Maine’s overall greenhouse gas emissions to reduce the state’s impact on global warming.

But as an all-day meeting of the state’s greenhouse gas initiative working group demonstrated Wednesday, actually making the greenhouse gases that contribute to global warming disappear is anything but easy.

Maine has been working on the greenhouse gas problem for years, starting with a regional agreement to act signed by New England governors and Atlantic Canada premiers in 2001.

Last year, state legislators put the goals in a statute, seeking a reduction to 1990 levels by 2010, an additional 10 percent cut by 2020 and a long-term reduction of at least 75 percent.

Wednesday, nearly 50 industry and environmental experts who have spent the summer drafting specific proposals in the areas of buildings, facilities and manufacturing, agriculture and forestry, transportation and land use, and energy and solid waste discussed an early draft of the plan.

The document lists detailed goals and dozens upon dozens of tools for reducing greenhouse gas emissions, and will be presented to the Legislature in mid-October.

The experts also analyzed data on estimated greenhouse gas production today, and found that transportation is the largest contributor, followed by buildings and manufacturing, electricity and solid waste and finally, agriculture and forestry.

Emissions from every sector are on an increasing trend, however, and despite the proposals – some controversial – that have been made, they won’t quite get Maine down to its target emissions by either 2010 or 2020.

“We knew it would be difficult to meet the goals. Even if we do find ways to adopt all these measures, we’re still not quite there. But I’m optimistic that it can be done,” Gov. John Baldacci said, addressing the group Wednesday.

“People are beginning to recognize that we each have a role in this,” he said.

Reducing greenhouse gases at any level also reduces air pollution, harm to human health and in many cases the cost of doing business, he said.

“It’s being smart about the economy, and being able to realize benefits both for our air and for our pocketbooks,” Baldacci said.

Wednesday, members of the group debated a long list of ideas, ranging from straightforward educational programs to a more complex regional emissions trading program for industrial sources of greenhouse gases.

Overall, encouraging Mainers to use less fuel, and when they must, to use cleaner fuel, will likely be the broadest effort; with full consensus in the group on programs to encourage state, corporate and household responsibility, to reduce the miles that Mainers drive every year by encouraging alternative transportation, and to create energy from the methane byproducts that landfills already burn off.

Other proposals were more controversial, such as requirements for “cleaner” ethanol and biodiesel-blended fuels; a zero emissions vehicle program, based on a California effort, that would force Maine auto dealers to keep more hybrids on their lots; and a plan to reduce excise taxes for efficient vehicles while increasing costs for those that are high greenhouse gas emitters.

Several of these items were deemed crucial for approaching the greenhouse gas reduction goals by Environment Maine and the Natural Resources Council of Maine in a report issued Monday.

More far-reaching recommendations included such ideas as boosting the protection of farmland and encouraging Mainers to buy locally produced food, thus lowering transportation costs and supporting less-polluting organic agriculture.

Reducing sprawl developments and protecting non-polluting landscapes like farmland, was also encouraged, specifically through the Land for Maine’s Future Program, which is currently in limbo, due to the state Legislature’s reluctance to pass a bond package that would have provided the program with funding in November.

The forestry working group made some similar suggestions, but will continue its efforts, with a meeting scheduled for July 29, because the emerging scientific data about forests’ role in both emitting and trapping greenhouse gases took a great deal of work to quantify.

Still, the draft plan discussed Wednesday included countless numbers – analyses of the tons of greenhouse gases that could be reduced and the economic costs or benefits of such action – and some group members raised concerns that the figures may not be precise.

But ultimately, the group decided to include all its proposals in the final report, as well as comments regarding the benefits, drawbacks and data limitations of each.

With a full menu of ideas and information, legislators can craft better laws than if they’re simply given a policy mandate, several group members said.

“You can get lost on the way to the goal if you describe the vehicle to the Legislature,” said Wendy Porter of Interface Fabrics Group.

The Legislature is not required to formally accept the plan this fall. However, most of its proposals will likely be considered either by Legislators or the Board of Environmental Protection in coming years, Department of Environmental Protection Commissioner Dawn Gallagher said Wednesday.

Although there is no public hearing process scheduled at this point, all of the group’s recommendations and supporting scientific and economic data are available to the public online at http://maineghg.raabassociates.org.