While I disagree on the level of man's involvement in actual climate change, I think we do enough damage to the environment. We dump tonnes of trash, gallons of chemicals, and use a metric eff-tonne of non-renewable resources. Responsible environmentalism works on fixing those things, not attempting to change some percieved threat that may or may not be related to man's involvement.
"I would rather be exposed to the inconveniences attending too much liberty than to those attending too small a degree of it." Thomas Jefferson