Not true on either account.

Please read the articles cited on this thread for cellphone-cancer correlations. It's very telling that industry-sponsored studies show no issues (one even disingenuously purports a cancer protection benefit!) while independent studies, including one Nokia accepted, show at the very least a suspicious correlation. More work is needed to prove/disprove causation.

As for global warming... one would have to be extremely naive to think man has no impact on climate. Vostok ice core data showed very strong evidence that temperatures and atmospheric carbon content followed very predictable cycles for hundreds of thousands of years and then spiked abruptly and significantly right at the industrial age, and still rising. That's not evidence of causation, but it's too damning to dismiss.

The real dispute isn't over man's obvious impact, but rather, what the carbon data means. Vostok shows that carbon increases LAG heat increases, which strongly suggests carbon is a red herring in the debate.

We should be focusing on airborne particulate matter, the real enemy to our lungs and environment. The focus on CO2 leads down a rabbit trail.