Even going interplanetary; that is only linear growth -- go to 1 new sun, get 1 new sun of energy!
Exponential wins in the end no matter what.
Then very soon, the earth will be overrun with such machines, and we can go interplanetary, then consume the sun to go interstellar. At least, whoever that remains after the grey goo takes everything else would go interstellar...
However had energy use increased at 2.9% since 1990 it would be nearly twice as high as it really is (4.2GToe vs 2.3 in 2018)
The Earth as a whole, with rapidly industrialising countries like China and India, global energy use from 1990 to 2018 only increased about 1.5% per year.
The world is becoming more efficient, and ultimately there is a limit to consumerism - I personally use less energy today than I did 20 years ago, and I'm sure that's the same for many people in the west. As transport becomes more efficient, there's only so many times you can go on a plane in a year (144 was my own record, but lets say it's 1000), after that point energy use on airplanes can't increase - there just aren't enough hours in the day.
> The abundance of deuterium in ordinary water would allow us to have a seemingly
I mean isn't it obvious that we are missing opportunities here? Are we really that complacent that we can't achieve anything on a grand scale anymore? Plant solar panels everywhere that there is not agricultural land and meets the criteria for energy efficiency. Fill in the all the roofs. It's vacant space. Spend billions more on fusion research.
> The merciless growth illustrated above means that in 1400 years from now, any source of energy we harness would have to outshine the sun.
Hopefully by that time we'd be an interplanetary species. Unless we imagine we can keep digging all the way to the core to extract resources down here. When all the good stuff is literally sitting out there waiting for us to plunder.
> Chiefly, continued energy growth will likely be unnecessary if the human population stabilizes.
I doubt our insatiable hunger for more, more, and more will stop anytime soon - even if the numbers stagnate, our egos will grow bigger and bigger and we'll want more and more. It's in our nature. So why not go beyond our planet for that never-ending "want"? Consumer everything that's out there and turn into shiny new crap for down here. Once we are done, eject it into the sun and keep the earth tidy.