What About Global Warming?

I read through several Global Warming threads and saw many things that were curious. Then I came across this article:

http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html

While I have not made a decision on the human contribution to Global Warming, I have a tendency towards a neglible impact. I believe that Global Warming is a natural process and that the natural has a greater impact on the climate than human influence. Certianly, humans cause an impact but it is usually a whisp in the spanse of time and space.

What do you think about the article?