Maybe. But that still doesn't get around the fact that we are not helping the situation. While the proportion of climate change attributable to humans versus natural cycles may not be precisely measured, no credible scientist is making the claim that humans are not contributing to climate change in some way. It therefore seems foolish to believe that the current climate change will be an exact mirror of a previous cycle, and thus it seems equally foolish for humans to not attempt to mitigate our effect on the environment.