Of course. But implying that man can somehow change this is pomposity at it's finest. We're not even close to being that powerful. Like George Carlin said "the earth will shake us off like a bad case of fleas".

There are so many variables and man has only collected data for the past 150 years. We aren't even close to understanding what our contribution is to this. Of course, it makes sense not to add to the problem, however, I'll bet you that even if we do change our ways so that our carbon footprint is completely invisible, mass extinction will still occur and on the schedule that the earth determines, not what we determine.