How do you make a better future of earth?

be nice to people

Its all downhill from here bud.

you can recycle, conserve water, drive an eco safe or hybrid car, don't or use less of air poluting self care items like hairspray, during the winter drain out your pool or cover it, etc...

You cannot make it a better place. It is the only place we can live. You can, however, make it a worse place. But there is no need to worry about that. Politicians are on the job, and doing very well...

you should know the mistakes you made in your past, so it means don't make the same mistakes again in order to have a future's better past.