text: Good post.  Let me add one more thought.
  
  Whether man is the primary contributor to climate change or not, it is still a fact that man-made greenhouse gas levels are rising.  So, if greenhouse gasses are contributing to climate change, all contributors (primary or otherwise) need to act.
  
  Would someone opposed to Planned Parenthood argue that it's okay to contribute to them as long as one is not the primary contributor?