The effects of climate change are already being felt across America. In Alaska, rising sea levels and eroding coastlines have forced a dozen different communities to relocate. In the Southwest, the risk of forest fires is increasing, water supplies are dwindling and native animal species are coming under threat. Scientists estimate that if left unchecked, climate change will affect millions of Americans in the years to come.

American Indian communities are among the most vulnerable as the planet warms, and they've been at the forefront of the movement to address climate change. One of the leaders who has emerged is Karen Diver, the chairwoman of the Fond du Lac Band of Lake Superior Chippewa, an American Indian tribal community in northeastern Minnesota. Last year, Diver was one of two tribal representatives who served on President Barack Obama's Task Force On Climate Resilience, and she pushed the government to adopt a greater sense of urgency in tackling climate change...