"We've always lived off the land and off the waters and continue to do that. But we're bearing the burden of living with these conditions today," Williams said.

Sen. Daniel Akaka, committee chairman, acknowledged that environmental changes are widespread, but the Hawaii Democrat said native communities are disproportionately impacted because they depend on nature for traditional food, sacred sites, and for cultural ceremonies. Several tribes already are coming up with plans to adapt to the changes and federal agencies are assisting with resources, Akaka said.

Members of several West Coast tribes and Alaska communities have been in Washington this week for a symposium at the Smithsonian Institution's National Museum of the American Indian on the impact of climate change on indigenous people and their communities. The symposium, titled First Steward, brought together tribal leaders, people experiencing the changes and scientists.