offshore nuclear reactors, guys. Come on. We have the technology to make this happen right now. It's our safest, best bet in the short term, but it will help until we find something to fill the void left when we abandon or run our of fossil fuels.
Regarding the whole issue of strip mining in Africa and elsewhere, we could have been working on technology decades ago that would have had us mining asteroids by the mid 21st century. Asteroids are probably a great source for a lot of rare minerals and resources such as water, gold, iron, zinc, lithium, and many more. Once this becomes a viable and affordable means of gathering resources, mining should become a thing of the past on the planet Earth. To say nothing of the riches Mars and The Moon likely hold within their crusts for future space miners