Information from Bewitched website:
Climate negotiations can be so simple! Those lagging behind learn from the front runners how to finally protect the climate. And those who suffer most from climate-induced storms etc. join forces. The bigger the conference the better, however, some countries will just not stop negotiating.
Players are climate diplomats who try to organize conferences for like-minded countries. On the one hand, they want the conferences to be as big as possible. On the other hand players who are the first to have no countries left also have chances to win the game. Hence, at some point it makes sense to hand over countries to more "competent" colleagues, or to collect as many countries as possible in order to hold at least one big conference ...
Gameplay:
Players take turns. In your turn you play a challenge, asking all players to compare one card each from their hands in a category you choose. The lowest value wins all cards. Afterwards you may play a conference of like-minded countries. However, two participating countries are always discontent and thus return to your discard pile. All other participants leave and score for you. Hence, the bigger the conference is the better.