This comprehensive piece joins the other links I have on the subject which because of its global importance and what decisions which will be made that affects us all leads off my in my webpage. http://www.theusmat.com/ Intro to those links is a satirical piece I did where this question was posed to the Pope and his response, which I hope readers find humorous but covers the question and shoots down positions.
Here is another good summary of the issue http://www.freerepublic.com/focus/f-news/1732479/posts