I would like to say that I believe the planet is warming, I doubt man can control that, I do believe we can add to the problem in a small way, I do not believe we can stop/reverse it, I also believe those who seem to attempt to deny it (add whatever names you want here, you might even include yours from reading your original post) and yes I believe it goes in cycles which likely has a major effect on life here and the extinction of it which has historically permitted new varieties of life to evolve.