Carbon footprint is a measure of the impact our activities have onthe environment, and in particular climate change. (answers.com)
I don't know which particular climate changes you are interested in, but I suggest you pick up a copy of a good climate textbook such as The Earth System by Lee R. Kump, James F. Kasting, and Robert G. Crane. (realclimate.org)
Those areas started to appear in August, if I recall correctly, and I can't say for sure if this is related to a particular climate change. (fieryfoodscentral.com)