In what could be the simplest explanation for one component of global warming, a new study shows the Sun's radiation has increased by .05 percent per decade since the late 1970s.

The increase would only be significant to Earth's climate if it has been going on for a century or more, said study leader Richard Willson, a Columbia University researcher also affiliated with NASA's Goddard Institute for Space Studies.

The Sun's increasing output has only been monitored with precision since satellite technology allowed necessary observations. Willson is not sure if the trend extends further back in time, but other studies suggest it does.
http://story.news.yahoo.com/news?tmpl=story&ncid=96&e=2&cid=96&u=/space/20030321/sc_space/sun_s_output_increasing_in_possible_trend_fueling_ global_warming

Remember the following line, though:
That does not mean industrial pollution has not been a significant factor, Willson cautioned.
It's not just the sun's fault.

You know there's other "greenhouse gases" in addition to CO2, don't you?

True, but carbon dioxide is the main offender.