We could rely entirely on renewable energy by the year 2050.

A sunflower blooms in front of the solar array at Sterling College, in Craftsbury, Vermont. sterlingcollege/Flickr

Pearson said we won't need to use fossil fuels to power things on the ground, like houses and cars, by 2050, but that it will still be necessary to run planes.

Improvements in underwater cabling will allow countries to use solar power from places like the Sahara Desert to power their entire country. The ability to draw solar energy from areas with more access to sun will increase our reliance on solar power over time.

"I'm very optimistic that maybe by 2030 we might start seeing these very large solar farms appearing in the Sahara," he told Tech Insider.

He added that nuclear fusion is also on track to power homes by 2045. China actually hit a huge milestone recently when it was able recreate solar conditions for well over a minute at its nuclear fusion plant.

"We don't need fossil fuels on the ground past 2050," he said.