Correct. Other bodies in the solar system are warming as well. Climate scientists know this. In fact they know there are a number of factors which can influence the temperature here on Earth. That's why they've performed many experiments and collected enormous amounts of data to determine to what extent each factor could possibly be responsible for the warming we've seen. Greenhouse gasses unquestionably contribute far more to recent warming than solar activity, although solar activity is definitely a factor. This is all summarized on the Wikipedia entry for Global Warming (with appropriate sources).
As a broader point, science is hard. Blogs, news reports and movies will never accurately convey it, and often intentionally mislead. The only thing that makes sense to me is to trust the scientists. The (US) National Academy of Science in particular is filled with very, very smart people and has a historical record of speaking purely from scientific considerations (ie, it's objective). They believe that anthropogenic climate change is real and significant. No scientific body of remotely comparable credibility disagrees; virtually all similar institutions from other countries have reached the same conclusion.
I'm not a climate scientist, so I don't know with firsthand certainty the truth of the matter. But, forced to choose (for example, as a factor when deciding whom to vote for) I listen to the most trustworthy organization I can find. And their conclusions are clear.