Feedback on the K-Mod global warming system

The new global warming system is one of the first things I added in K-Mod. There are a lot of different tunable aspects of it, but I haven't really changed it much since it was introduced because for me it seems to already work pretty well. But that's just me. I know that different people play on different game settings, with different map types, and different styles of play; and so global warming might be a bit different for different people. I'm interested in hearing any feedback about it.

Is the threshold crossed at around the right time in the game? Is the happiness effect too strong, or too weak, or too soon, or too late? How about the rate of global warming events: too many? Not enough? Maybe too few at first and then too many later on? Do they strike too often in the cold areas? Too often in the warm areas? Is the global warming an interesting part of the game? Or maybe it's a chore, or boring, or just insignificant?

I'm not just asking about those particular questions. Just give whatever feedback you like.

If you have any comments about the strength of the global warming effects, please state some of your game settings: map size, game speed, difficulty level, and perhaps even map type... Those things may affect how it all works.

(here's how GW may be affected by those settings)