What if there was no more oil?

The Swedish climate activist 16-year-old Greta Thunberg recently set sail across the Atlantic on a solar and wind-powered racing yacht to attend climate summits in the U.S. She was offered the use of the yacht because she refused to use a transportation method that would further contribute to global warming.

That got me thinking about what-ifs.

What if there was no more oil to power planes or ships? Our modern world came into being because of petroleum, which has allowed humanity to accomplish unbelievable things that we take for granted today.

How unbelievable? Consider that a single barrel o...