It is incumbent on every generation to pay its own debts as it goes. A principle which if acted on would save one-half the wars of the world.
A safe but sometimes chilly way of recalling the past is to force open a crammed drawer. If you are searching for anything in particular you don't find it, but something falls out at the back that is often more interesting.
On the environmental front there's concern about global warming and high levels of carbon dioxide, and trees take in CO2 and store carbon.

