i was thinking about how to make the fire node useful, and i figured if it was done more nimbly itd be good, like
tile->(goes to)tile (yield change)
deserts->deserts (no yield change)
plains->desert+remove forests/ancient forests (lose all yields, but easily fixed with spring and bloom)
tundra->plains (+1 production)
ice->tundra (+1 food)
ice(feature)->removed (+1-2 food, +1-2 trade)
jungle->new forest (+1 food +1 production)
grasslands->plains (-1 food +1 production)
ocean/coast->grassland (+1 food, -1-2 trade)
with those, which make sense to me atleast, the general changes would be useful or atleast easily made useful except in the case of plains to desert (which spring fixes), loss of forest (which bloom fixes), and grassland->plains (which would take longer to fix, but still, its a trade of 1 food for 1 production).