The author didn't mention it but there is a scale for measuring the level of technological advancement called http://en.wikipedia.org/wiki/Kardashev_scale that takes the energy consumption of the civilization into account. According to the linked article, we will be Type III in 2500 years.
If im not mistaken i remember Michio Kaku saying that we will reach type three in about 1 million years from now where humans can build dyson spheres and harness the energy from galaxies, where we would be able to send robots to search other galaxies and then create gateways for the actual type 3 civilization to travel through to them. We are currently as he states it at 0.7 and our greatest challenge is to break past the type 1 where it is the most violent, like a child moving into their teenage years.
Looking at the state of the world today we are kind of doing so, where type 1 allows humans to harness and completly understand the power of the planet (solar, wind, kinetic) we are developing systems to help us harness it however we just need to ensure we dont obliterate ourselves before we get there.
If we did produce a Type III civilisation I don't think it would be based on anything remotely like a collection of biological humans. Probably more like the god like entity playing with humanity in Missile Gap by Charlie Stross:
The population of the US in 1650 was 50k. Now it's 309 million. No surprise that energy consumption increased by a factor of about 10^5.
Also, the increase in world population isn't going to go on forever. Birth rates are decreasing in most countries - including third world countries. In fact, the population of many states in India is increasing not because of birth rates but due to increasing life expectancy. I can't find a cite now, but I remember an article which expects world population to stabilize at something less than 10B. If even that number seems worrying, remember that vast swaths of land in Central Asia, Siberia, Canada, Alaska, Australia and Antartica are virtually uninhabited: we don't even need to go the moon or Mars or something to find space for humans.
We do need to get our act together but our real problems are effective policy-making and governance. Not finding endless sources of energy.
"remember that vast swaths of land in Central Asia, Siberia, Canada, Alaska, Australia and Antartica are virtually uninhabited: we don't even need to go the moon or Mars or something to find space for humans." Uninhabited for a very good reason, with the exception of Canada and Asia, maybe. Seriously, Antartica?
Better to shove people into well-built structures in Antarctica and use more temperate land for food and energy generation than fill up every inch of what is traditionally considered "habitable" space and promptly starve.
A couple of years ago I went to a Joint European Torus (JET) reactor tour, the largest magnetic confinement plasma physics experiment in the world and the closest (current working) thing to a working fusion reactor.
The temperature inside the plasma on these things reaches 10s of millions of degrees Kelvin, but on the beryllium plated walls it's fairly cool (it'd have to be otherwise the tiles would be destroyed). They also had a smaller spherical tokamak called MAST that was quite interesting. We got to go into certain areas that are normally closed off (as they're normally shut down).
If we start thinking in the scale of thousands of years, I could very well imagine using this much energy, if we get some nice automated self-sustaining expansion going.
Robots that build solar panels (and more robots) from raw materials they gather, powered by energy they themselves are helping to create. It would be like sending a virus out, no need for any intervention once you get the process going.
They would go out and convert everything into whatever we need. In 2500 years they could even reach other stars.
The timeline starts at 1650, the height of the Renaissance, and projects forwards 2500 years. It would be more interesting to start at 500 B.C. While the author is making the point that 2% growth is silly, he is missing that there (if past history is to be gone by) will probably be a Big Reset followed by 1000 years of darkness, as before.
I fun thought experiment but before anyone does a nude run down main street screaming "we are all doomed" think about this. Our energy use is driven not only by technology requirements, but also population growth, which is likely to be far more limited in the future due constraints of land and food.
Don't forget that richer humans tend to get fewer kids too (this is only natural as the better life you get, the less improvement to your standard of living a child is until it dibs to negative when you move of the farm and into the city).
Sometimes I wonder if there was a device for nearly endless, nearly free energy (that was safe) if we'd have fewer wars or more wars (because war would be cheaper from the material side).
If we had a Dyson sphere, people would no doubt be fighting over control of it. One example of the preliminary stages of this is the fighting that takes place over the orbital elevator systems in Mobile Suit Gundam 00.
Yeah, the orbital elevators are multipurpose (i.e., to provide a more convenient launching point for spacecraft), but one of their primary goals is to provide electricity. And thus they are closely guarded by the 3 main power blocs (the Union, AEU, and Jinkakuren). Without energy, they are nothing, as can be seen from the countries that aren't a part of one of them and thus live in great poverty.
