This would certainly be another interesting challenge to overcome in playthroughs ... though I can see the reluctance to dump every kind of disaster on us at once. There are already grumblings in the player base at having the random disasters we already have. Having one that burns down all your available forest for no gain I could see being frustrating to such players (though they could add that each burnt forest increases fertility of the tile or somesuch). My personal desire would be that they introduce a Regrowth mechanic, where after X number of turns, a cut/burnt forest will grow back on the map if the tile is left untouched (Probably something like 30 turns, as that seems to be the default length). I know we can plant forests in the late game, but there should be some natural recovery as well...