All we need is an energy miracle. No pressure, kids.

So came the call from Bill Gates on Monday evening with the release of his annual letter. It tackles heady subjects with the billionaire's usual optimistically sober tone. Unlike letters past, Gates aimed this year's missive at teenagers instead of adults, arguing they're our best shot at solving the world's energy crisis.

The genesis of the note was a conversation the Microsoft co-founder and his wife Melinda had with a group of high school students in Kentucky. The students wanted to know what cereals the Gates family preferred and if Bill knows how to dance the Nae Nae. They also wanted to know which superpower Bill and Melinda would pick, and that question struck a particular chord.

The answers to the superpower question—Bill chose more energy, and Melinda chose more time—seem straightforward at first blush. They were the kinds of things that any adult desires. In the letter, however, Gates focuses not on being peppy for a tennis match but instead on the world's mounting energy crisis. Melinda likewise issues a global call for improvements in gender equality that would give women more time to pursue those things they care about most.

On the energy front, the most crucial part of the letter centers on an equation cooked up by Gates: P x S x E x C = carbon dioxide. He shows that changes to P (the world's population), S (services used by each person) and E (energy) will not be dramatic enough to get carbon dioxide production down to zero—something that has to happen, according to Gates, to avoid catastrophic consequences to global warming. The factor that matters most is C (carbon dioxide produced by energy).

Gates has talked quite a bit in the past about the need to come up with new energy technology beyond solar, wind, nuclear and all the rest. We'll need a major development if the world is really going to change its energy equation. In the letter, though, he puts a very fine point on the idea. "In short, we need a miracle," Gates writes.

When I say “miracle,” I don’t mean something that’s impossible. I’ve seen miracles happen before. The personal computer. The Internet. The polio vaccine. None of them happened by chance. They are the result of research and development and the human capacity to innovate.

In this case, however, time is not on our side. Every day we are releasing more and more CO2 into our atmosphere and making our climate change problem even worse. We need a massive amount of research into thousands of new ideas—even ones that might sound a little crazy—if we want to get to zero emissions by  the end of this century.

Ever the optimist, Gates expects just such a miracle to arrive within the next 15 years, and he expects it just might come from one of today's teenagers.

In the interview below, Gates expounds on his energy ideas and faith in the world's youth. The letter goes into more detail on that subject as well as Melinda Gates's thoughts on gender equality.