At one point I was a frequent reader of Arts and Letters Daily, a daily media update on literature, music, and culture. I'm not really a frequent reader of much online right now, but the creators of that website (which I still visit occasionally) have started another website called Climate Debate Daily, which links to articles that both support and challenge the idea that climate change is caused by human activity.

I wish there were more sites like this that extensively post new articles on important subjects.