This sounds very similar to toxic fallout(which could be a synonyme for acid rain).
But if I get you right, you want a fast progression, short duration event that will require fast reactions but doen't cause long-term problems, right?
Actually acid rain could reducde fertility for a period of time. Could be an overlay like snow, which get slowly washed away by water or by time reducing fertility by 100% on max, making only fertile soil able to grow crops in the worst case.
But if I get you right, you want a fast progression, short duration event that will require fast reactions but doen't cause long-term problems, right?
Actually acid rain could reducde fertility for a period of time. Could be an overlay like snow, which get slowly washed away by water or by time reducing fertility by 100% on max, making only fertile soil able to grow crops in the worst case.