Climate change will continue to trigger new innovative approaches. We will keep civilization but in a much smarter way. Two things are key to deal with the challenge
1) We need about 20 times more scientists and engineers
2) We need serious media campaigns to educate the public how to adapt their lifestyles
If we accomplish this, the change to our ecosystems and the reduction of biodiversity will be limited. If not, the human species will still survive but instead of 9 billion people eventually there will only be 1 billion people or so left competing for scarce resources especially food. This is not the Alan Weisman scenario (his book is really excellent) but something else.
Bottom line: We need to act wisely now without being scared.