Parts of the planets, including Earth, heat up and cool down on a regular basis. In all cases the actual change in temperature so far is will within the normal long term variability. One change, which look more an insturmentation anamoly than real data, may be significant, if it is real. Here is a graph that shows a sudden step change in the suns magnetic activity which occurred a few years ago.
http://wattsupwiththat.files.wordpre...agnetic-ap.png
What is real, by all accounts, is the fact that Solar Cycle 24 has not done anything yet. That could mean BIG CHANGES in our climate in the next few years. It is too soon to tell, but this is the most significant change in our solar system that I have seen. It could be that the suns Dynamo, the process that creates sun spots, has gone dormant. There are many, although not completely understood, consequences of that Dynamo shutting down.