ORONO – Former U.S. Sen. George Mitchell lamented what he says is “waning” resolve to tackle global environmental issues, but called Thursday for university researchers, grass-roots groups and local governments to lead the fight.

Mitchell, a Democrat who represented Maine in the U.S. Senate for about 15 years, recalled writing about such problems as climate change, deforestation, massive “dead zones” in the oceans and polluted rivers in his 1990 book “World on Fire.”

But 17 years later, most of those problems have not only grown worse, but the world faces such new environmental threats as the acidification of the oceans, Mitchell told several hundred people attending a University of Maine environmental lecture series named in his honor.

Mitchell then agreed with an earlier speaker, Yale University dean and author James “Gus” Speth, in saying that those challenges cannot be addressed through a “business-as-usual” approach.

“Given what appears to be waning national and global resolve to tackle these problems, I believe we will need even stronger efforts by local government, grass-roots organizations and innovation from the private sector,” Mitchell said.

“This will require new partnerships between groups of stakeholders that at first impression have divergent interests but who must be willing to come together to find better solutions.”

Both Mitchell and Speth said they are greatly concerned about humankind’s ability to balance the explosion in global economic growth with the needs of the environment.

Speth, who co-founded the Natural Resources Defense Council and served as administrator of the United Nations Development Programme, said that while the U.S. environmental movement has gotten stronger during recent decades, the degradation of the environment has worsened.

Speth pointed to research showing that personal satisfaction among a national populace is more closely correlated to social issues than income growth. He then drew a link between the improving the environment and strengthening key social issues such as human rights, education and ensuring that families have enough quality time together.

“I would argue these are environmental issues,” said Speth, who is dean of the Yale University School of Forestry and Environmental Studies. “They are the alternate to the destructive path we are on … so in the end we will see that sustaining people and sustaining nature is just one cause inseparable.”

Both speakers praised University of Maine researchers for their focus on environmental issues, including efforts to improve watershed health. They also forecast that those in academia will play a crucial role in solving global environmental problems.

“Our society needs institutions like this one that possess people with expertise in the scientific, technological and human dimensions of environmental problems, and this university has these in abundance,” Mitchell said.

Mitchell and Speth were the inaugural speakers in the Senator George J. Mitchell Lecture on the Environment. The annual lecture is a program of UMaine’s Senator George J. Mitchell Center for Environmental & Watershed Research.