Will give need asap. a short but detailed response would be - how can we minimize harm to the environment during the transition away from fossil fuels?

We can start slowly with the transition. Starting with solar panels or wind farms. Water is also a source of energy, and so is biomass, so we can, as the environment becomes more and more attained to renewable energy, add more varieties. Like geothermal energy, or hydrogen fuel cells. Over time, add more and more varieties while the environment is safe enough for it, and soon enough we'll be no longer using the harmful fossil fuels.