The conference will begin in Salt Lake City the night of July 10 and then move to Sundance the final two days.
The principal sponsor of the event is a group called the International Council for Local Environmental Initiatives, whose U.S. branch is located at Berkeley, Calif.
The organization works with local governments to reduce greenhouse gases that cause global warming.
"The best call to action is happening locally and the biggest impact is what happens at the local level," Grant said.
"It's really why our focus here at this summit is a gathering of mayors focused on a local solution versus a summit that would bring together federal policy makers."
Redford, a longtime environmental activist, became involved in the conference as a follow-up to the 1989 Greenhouse Glasnost event he hosted at Sundance that brought together U.S. and Soviet scientists and officials to discuss global warming.
Anderson has been active in speaking about the role of local governments in curbing global warming, including attending several international events.
Salt Lake City has implemented environmental initiatives such as buying wind power and using energy-saving light bulbs.
The city has also converted some city vehicles to natural gas.
The mayor's communications director, Deeda Seed, said local action is needed on global warming "in light of the fact that there's so little or no action taking place by our federal government."
Confirmed speakers include Heidi Cullen, on how climate change can affect local communities; Paul Epstein, associate director of the Harvard Medical School; John Holdren, director of science, technology and public policy at Harvard, and Jean-Michel Cousteau, president of the Ocean Futures Society.
Grant said the meetings will be limited to the attending mayors, with some sessions open to the news media.
- The Salt Lake Tribune
