PORTLAND – Although considered a national leader on global warming issues, Maine still needs massive investment in new technology as well as fundamental changes in lifestyle and business practices to prepare for the impending crisis.

That was the consensus of several hundred people who gathered in Portland on Wednesday to discuss how rising global temperatures could affect Maine’s ecology, economy and overall way of life.

The conference, called “Climate Change in Maine – Reducing Risks, Reducing Costs and Planning for the Future” drew environmentalists, government officials, business leaders and academics from across the state. Organizers with Maine Global Climate Change LLC said the purpose of the event was to initiate dialogue between the groups.

Many speakers praised Maine officials and businesses for working to reduce greenhouse gas emissions by increasing efficiency and investing in “green” technologies, such as biofuels and renewable energy. And many of those same speakers accused the Bush administration of ignoring evidence of climate change and undermining international efforts to fight it.

“We need to send a message to Washington that there is a problem and you can’t put your head in the sand,” Gov. John Baldacci told the crowd gathered at a University of Southern Maine conference center.

But the resounding theme of the event was that Maine and the United States are not doing nearly enough to prevent or prepare for global warming.

Predictions of how much the average global temperature could rise vary considerably, but several speakers at the meeting used the projection of temperatures rising between 3 and 5 degrees over the next 50 to 60 years at the current rate.

Sonia Hamel, a special assistant in the Massachusetts Office for Commonwealth Development who focuses on environmental issues, said an increase of 5 degrees could raise ocean levels by 1 meter (just over 3 feet). That would spell catastrophe for many coastal communities and major cities, she said.

For comparison, Hamel said, an increase of 6 degrees would make Maine’s climate similar to that of Charlotte, N.C., today.

During work groups, audience members brainstormed ways for Maine to use its existing resources to both work to slow the rate of global warming and brace for the impacts of climate change.

Maine could significantly reduce its reliance on fossil fuels by building wind turbines, tidal energy facilities, and more biomass plants. Several speakers also touted the potential in Maine for generating biofuels from crops and bioplastics from wood.

Representatives of several companies operating in Maine – including the Hannaford supermarket chain and carpet manufacturer Interface – also gave presentations on corporate efforts to reduce greenhouse gas emissions or increase energy efficiency.

Jim Walker, chief operating officer for The Climate Group, an international organization working to promote business and government leadership on climate issues, said his group stresses that adopting “green” technologies or strategies can still be profitable. Walker said a low-emissions economy is inevitable in the future.

At least 74 major corporations reduced their greenhouse gas emission levels since 1990, with most realizing a profit from the reductions, while 17 U.S. cities saved $600 million in 2004 from greenhouse gas emission measures, he said.

“Early movers will gain the long-term advantage,” Walker said.

But Mainers also will need to change their lifestyle in order to adapt to and fight global warming, several speakers said.

Alan Caron, president and founder of the anti-sprawl group GrowSmart Maine, said that a generation ago rural Maine’s 400,000 residents worked largely locally in agriculture and forestry. Today, rural Maine’s population has swelled to roughly 700,000 people, most of whom commute to work.

Caron said Maine residents’ migration out into the countryside was based on $1 per gallon gas – a lifestyle he predicted will become increasingly unsustainable for both economic and environmental reasons.