He is committed to clean air and clean water and to conserving open space. He says global warming can no longer be ignored. He says reducing the U.S. dependence on oil is not only a greenhouse gas issue, it's a national security issue. Americans needs to limit carbon emission by harnessing market forces that will bring advanced technologies, such as nuclear energy, to the market faster, which would reduce our dependence on foreign supplies of energy, he said. He favors building the proposed national repository for nuclear waste at Yucca Mountain, which is 90 miles northwest of Las Vegas.

McCain's Web site: "I believe climate change is real. I think it's devastating. I think we have to act. And I agree with most experts that we may at some point reach a tipping point where we cannot save our climate. I don't think we're their yet. But the overwhelming evidence is that greenhouse gasses are contributing to warming of our earth and we have an obligation to take action to fix it," he said in a video on his Web site.

YouTube video: McCain addresses how decreasing our dependence on foreign oil is a national security interest.

YouTube video: McCain talks to an Iowa crowd about his ideas on ending global warming.

Las Vegas Sun Story: McCain didn't mind taking an unpopular stand in Nevada concerning the proposed national repository for nuclear waste being placed at Yucca Mountain, which is 90 northwest of Las Vegas. "I think it's a suitable place for storage," he said last April while speaking to Clark County Republicans.

— Las Vegas Sun new media managing editor Dave Toplikar compiled this report.