How has environmental change affected hominid evolution? How did humans adapt to late Tertiary cooling? It is my understanding that environmental change might be one of the most, if not the most, important factors contributing to hominid evolution but as a total beginner in the subject I would like to learn. So, if anybody has any information or opinions they would like to share or if anyone could point me towards some relevant scientific journals that would be greatly appreciated. Thanks a lot ahead of time.

Does anyone have any opinions or information they would like to add?

http://talkorigins.org/faqs/homs/ is a good place to start. There are lots of sources out there for hominid evolution but origins should be one of the best starting points.