[Apes]

Efficiency isn't a silver bullet. There's a limit to free gains from efficiency - you can't go past 100% efficiency, and even at 100% efficiency, you still need to spend energy to do things. It will always take at least 4190 Joules to heat 1 kg of water by 1°C. Even with perfect efficiency, you can never beat that number.

And the closer we get to 100% efficiency, it gets asymptotically more difficult to improve efficiency. Look at the average fuel efficiency of all cars in the US. Going from 12.5 MPG in the 1970s to 25 MPG today was "easy". Going from 25 MPG to 50 MPG will be extremely difficult. Going from 50 MPG to 100 MPG is nigh on impossible.

It gets even more depressing when you realize we have to double efficiencies every time the world doubles its population just to tread water and keep everyone with the same quality of life, while also having no additional effect to the environment.

The world's population is doubling every 60 years. I doubt we can keep doubling efficiencies for even the next 60 years.

Realistically, if we want to create a sustainable world economy, the world is going to have to undergo a massive shift to greener technologies than we're using now, and either the quality of life or the population across the world is going to have to decrease dramatically.

[oceanplexian]

> It will always take at least 4190 Joules to heat 1 kg of water by 1°C. Even with perfect efficiency, you can never beat that number.

You can. A great example of technology that produces greater than 100% efficiency is a heat pump. You can actually buy commercial heat pump tank water heaters that are much greater than 100% efficient at turning electricity into hot water. The energy comes from the ambient air, but the Earth has no shortage of heat energy that can be recovered to do useful work.