In terms of temperature change - nuclear winter is estimated to be a ~3C global reduction in temperature for ~10-20 years. And yes, you're right, photosynthesi

In terms of temperature change - nuclear winter is estimated to be a ~3C global reduction in temperature for ~10-20 years. And yes, you're right, photosynthesis would probably cease. We're going to see similar problems in the opposite direction, probably drought on a scale heretofore never experienced in human history in temperate areas. Imagine the climate of Los Angeles moving north to Vancouver BC, and similar cascading effects across the board.