The future of the Planet . . . and sadly, how to solve the problem

There's a lot of news at the moment about how we've messed up our planet, and the next two generations are complaining and demonstrating about how we have let them down.  To a certain extent they are right.  I own shares in a company that mines coal and iron ore.  Others have shares in steelworks, and more still have money invested in metal goods.  All the investment in the world contributes to global warming.

But we breathe
Cows fart
Trees burn
Dead animals and plants decay

In Science, (you were probably asleep at the time - I know I was!) you learned about the Law of Conservation of Energy.  You know the one.  When water flows over a waterfall, the water loses Potential Energy, gains Kinetic Energy, and when it gets to the bottom, some heat is given out.  (It's a well-known fact that the water at the bottom of a waterfall is slightly warmer than at the top.)

But that's not the important bit.  There's a bit that almost everyone forgets.  The Law starts with "In a CLOSED SYSTEM . . ."  The Earth is a closed system.  Almost every time energy changes from one sort to another, some heat is given out.  This warms the system, which is the Earth and its occupants.

I am sitting in a cool room.  If I stand in front of the heat pump outside, it feels hot, because hot air is being removed from the house.  In winter, it's the opposite way round.  A century or more ago, a chemical reaction between the fuel and the air (logs or coal) produced heat (and using chemical energy, created carbon dioxide!)

The important part of the Law turns out to be "In a closed system".

The more organisms that we have on this planet, the more energy is changed, more heat is given out and our closed system, the Earth must, by the Laws of Physics warm up.

So, scarily, we have to reduce the number of homo sapiens on the planet.  I say that as a scientist with no hidden agendas, not as a politician.  I was born in 1946 and one billion more people are living on this planet now, all converting energy and producing heat.

Somehow, and I have no idea how, we have to find a way of removing heat from this closed system we call Earth.  How we do it, I have no idea, but if we don't, ecosystems will change including extinctions, the planet will heat up, and the last person will die of suffocation when the oxygen level drops significantly.  Whatever we do, ecosystems will change irrevocably.