Future energy sources
The next generation will be much more aware of what they do to their planet, and many inventions will continue to show up as they have done since we started to cook our food.
So the author is not worried about the future energy resources but aware we must and can do things differently. In Scandinavian
Solar panels can produce electricity even in Winther. And as we have strong winds, wind turbines play a major role in our future supply of energy from the sea.
Sweden and Norway have their streams and waterfalls as a primary source of electricity supported by Solar panels and Wind turbines
Our Good Neighbors on Island can take advantage of a Vulcanian underground with plenty of hot water, and they are very clever to use that in their production.
Every country has their energy source. Sometimes, it needs development.