Yes, and it is caused by humans. But if you have friends, colleagues, relatives or readers of your blog or facebook feed bothering you about this, telling you that Anthropogenic Global Warming (AGW) is a hoax or a false claim or a lie, you may want this tool:
The Debunking Handbook: now freely available for download
The Debunking Handbook, a guide to debunking misinformation, is now freely available to download. Although there is a great deal of psychological research on misinformation, there’s no summary of the literature that offers practical guidelines on the most effective ways of reducing the influence of myths. The Debunking Handbook boils the research down into a short, simple summary, intended as a guide for communicators in all areas (not just climate) who encounter misinformation.