There was an interview w/GT a short while ago in which the interviewer tried to "understand" how the US being required to reduce its emissions was going to affect Chyna. She spewed the canned response that larger countries, Iike the US, needed to take the lead and it would logically follow that Chyna would (feel social pressure or guilt, ha ha ha ha, and) follow.

So, it would seem that this announcement might be a direct F-U to that (flawed) theory.