Man has been increasingly destructive to the earth starting around the industrial revolution. We have really shown an impact on the environment in a negative way. Historically man had a much better way of interacting with the environment that we're just now finding out about. There's a book called 1491 that explains the ways past cultures have had a much more homogeneous relationship that we are just now finding out. Permaculture techniques and an overall less destructive view helps. Humans are wildly creative and are amazing problem solvers. If we really think about it and get the top minds to figure solutions to the problem then we would have no shortage of viable solutions

The hard part is that the people that need to change are the multibillion dollar companies that are thriving on this. Oil companies, food industries, retail giants, you name it. That's why it seems that even though we have the tools and then ingenuity to fix the problem, it would be more likely to go to a different planet then try and take money away from the companies that rule the world.