Each space can gain a Chaos counter during the game. The total number of Chaos counters on the map affects the changes in weather during the Weather phase.

In the Autumn weather phase, populated tiles generate new Chaos counters.

The number of chaos counters generated by all of the tiles is halved, rounding down, and the remaining chaos counters are placed on random spaces on the map without chaos counters. If a chaos counter would be placed on a Forest tile, there is a chance it is discarded instead.

Coverage

The effects of global warming depend on the amount of the map that is covered by Chaos. Since the sizes of the maps vary, this wiki expresses that amount as a percentage of the nearest multiple of 125. Effects worsen whenever the amount reaches another multiple of 25N, which is 20% of 125N. Aridification affects a random selection of 4N spaces, which is roughly 3%. Firestorm affects a random selection of 10N spaces, which is roughly 8%.

Since two-player maps have 260 spaces, the effects of global warming worsen for every 50 Chaos counters present on the map, Aridification affects 8 spaces, and Firestorm affects 20 spaces.

News

Every time the effects of global warming worsen, a newspaper appears to all players that highlights the resulting gameplay changes.