It's taken a state sustainability task force a little more than a year to come up with a draft plan meant to guide the state more than four decades into the future.

On Saturday, the Hawai'i 2050 Sustainability Plan will be unveiled at a sustainability summit at the Hilton Hawaiian Village.

So far, the major players on the task force have included representatives from government, the business community, the military, nonprofit groups as well as environmentalists and economists.

The task force has had to strike a balance between all these interests and will have to resonate with the public in order for it to be more effective than the three-decade-old Hawai'i State Plan, which has been largely ignored since the 1970s.

Keynote speaker Terry Tamminen, who has led similar sustainability initiatives in California, said the task force will have to hear from other voices — teachers and academics and Hawaiians, for example — to win enthusiasm from the greater public.

"You need a shared vision and to agree on a blueprint for achieving it," Tamminen said.

The draft, which draws on input from all sectors of the community, will be available for further public comment before the report is put into final form to offer to the Legislature next session.

The wants of the environmentalists, for example, will have to be measured by the needs of the business community.

"We all need jobs, but we also need to rethink the ways we've been growing and protect the economy as well," he said.

California has not developed a comprehensive plan, but Tamminen helped develop that state's environmental action plan, which sets benchmarks for the state to meet in terms of renewable energy, moving away from petroleum as a transportation source and bringing down greenhouse gas emissions.

He said the summit is a good way to open communication with the broader community so that people start thinking about what they're willing to do to bring about the future they want to see.

Reach Treena Shapiro at tshapiro@honoluluadvertiser.com.