This will definitely go into the FAQ I'm putting together.
One thing I would suggest for either the FAQ and/or the next rulebook print run is:
Make it very explicit that only the player who triggered the threshold gets the bonus, not every player. This is already quite clear from the wording ("If you raise the parameter to this point, you
also get the attached bonus"), but it's not necessarily intuitive or thematically obvious that only a single player benefits from the greenhouse/thawing effects that are occuring on the whole planet.