my opinion is impossible to reverse it all. About pollution and global warming can be drowned with we start planting trees before it's too late, about reversing is clearly impossible because we can not turn back time unless we have a time machine which is impossible. all we can do is to limit the use of pollution by using alternative energy such as conventional machines replaced by electric machines or maybe in the next few years will be found new machines that do not cause great pollution, that's the task of scientists today but of course assisted by the Society.