That's why we call it "climate change", which contains global warming and global cooling (according to research, the globe's temperature has decreased). It's not saying we shouldn't plant more trees and try not to decrease CO2 levels in the air, however, we must acknowledge that we as humans can't do much. One volcanic eruption completely cancelled all of our efforts in the past decade to reduce CO2 emissions.
Several parts of the globe are much warmer than usual (this is a matter of opinion sometimes, when you hear people say "global warming" you may be inclined to feel it is warmer even if it is not -- I forgot the exact term for this). However, certain places are also getting cooler. And I don't state this as an opinion, I state this as a global fact found through conducting research on how the weather has changed. The climate is rather different from before. For instance, we are now worrying about lower pH levels in oceans. A bit of research should tell you that they actually used to be much lower than they are now.
Of course, I agree to planting trees, reducing CO2 emissions, etc. etc. but I just feel the need to point out that it'll be difficult. Our world is made to change, one of the reasons why it has gone through ice ages and times like that. I was surprised when I found out that it wasn't really "global warming" and was "climate change" as well.
KKLT, I'm not quite sure about that. Weren't we all taught that CO2 depletes the ozone layer? Wouldn't that allow even more of the sun's rays in, coincidentally being less capable of blocking out the harmful parts? I also heard from somewhere (not sure if this is true or not) that there is a wide, gaping hole in the ozone layer right now. I forgot what the supposed effects were though...