Seed Bomb: Aerial Bombardment to Reforest the Earth

Take equipment developed by the military for planting fields of land mines and adapt to use for planting trees.

Another example of R&D for military purposes turning into something to help humans/the planet. It's sad that the United States, in particular, feels they need to spend taxpayer's money on developing war equipment instead of just skipping to the part where social good comes into play with these inventions. As a country our priorities are incredibly regressive.