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Comment by imgabe | Hacker News Reader

> there's no way of our GDP keeps growing indefinitely while reducing our ecological footprint.

Yes there is. We are vastly ineffecient with our use of energy. Fusion power, better use of solar, wind, geothermal power, better energy storage. The amount of solar hitting the Earth every day is several orders of magnitude larger than what is needed to run society at our current level. There is no shortage of energy, only our ability to make use of it.

Obviously nothing grows indefinitely. Eventually the sun will go supernova and consume the solar system. For an amount of energy needed to sustain human life comfortably, there is more than enough.

The degrowthers would have us go back to living in grass huts and dying in droves from diseases we have long since eradicated. It is not a way forward. It is species suicide.

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The indefinite growth theory is discussed in this chance meeting of an economist and a physicist.

"Alright, the Earth has only one mechanism for releasing heat to space, and that’s via (infrared) radiation. We understand the phenomenon perfectly well, and can predict the surface temperature of the planet as a function of how much energy the human race produces. The upshot is that at a 2.3% growth rate, we would reach boiling temperature in about 400 years. And this statement is independent of technology. Even if we don’t have a name for the energy source yet, as long as it obeys thermodynamics, we cook ourselves with perpetual energy increase."

https://dothemath.ucsd.edu/2012/04/economist-meets-physicist...

Not all methods of using energy require releasing heat to space. Solar energy uses heat and light that comes in from space and converts some portion of it to useful work, reducing the amount of heat that needs to be released to space.

That also ignores the fact that technology gets more efficient. A laptop today uses 50W and is thousands of times more powerful than a roomful of computers 50 years ago that used thousands of watts. It’s doing much more and releasing a fraction of the heat.

Same with wind energy: wind is ultimately created by solar energy heating the atmosphere, so wind turbines are simply removing some energy from the atmosphere and converting it to useful work.

Its still exponential growth so it will eventually mean all possible useful wind and solar is used up. Then what?

If we truly used up all solar and wind power on the planet (which is a mind-bogglingly large amount of energy) there is still nuclear fission which is also a very large amount. Then if we invent fusion, that's basically infinite energy for free. And on top of all that, Earth is not the only planet, and the Sun has energy that does not only hit the Earth, so we can be construct a Dyson sphere.

Energy from our human scale today is basically infinite when we count all the sources available to us.

Solar and wind were brought out up because if any other energy source (like fusion) was used, then waste heat would be generated that would eventually (at exponential growth scales) boil the planet. And we could only, even the best case scenarios, ever only use a fraction of the available wind and solar that exists. Biological life is also solar powered so there's only so much you can take before that's an issue.

True that.

> there's no way of our GDP keeps growing indefinitely while reducing our ecological footprint.

This is at its core not a truth, but really an unsound belief system that could have been phrased the same about water quality, acid rain, leaded gasoline or the ozone hole. Yet these have all been tackled by humanity as a whole already, because we saw a pretty bad impact on our livelyhood quickly.

No doubt, CO2 is really the greatest challenge of all times, compared to nearly any global problem before. But it‘s far from insurmountable, and definitely not directly coupled to growth.

All it would take is a (literal) moonshot effort: Taking the same funds as the Apollo Program (in 2022 adjusted dollars) would be enough for a full transition.

Before this decade is over. Not because it‘s easy, but because it is hard.

Unfortunately, the US seems to have run out of massively visionary presidents since 1968.

Energy problems is just one of ways in which our societies can get into a decline. There's also loss of arable land (industrial farming is slowly but surely destroying the soil across the world), destruction of biodiversification, leading to freak incidents (one pest/disease wiping out lots of crops, forests, farm animals, or humans for that matter), depletion of minerals in the Earth (who knows if even right now there's even enough lithium available for widespread deployment of electric cars etc.

It's technically possible now to synthesise carbohydrates, fats, and proteins directly from the air: in effect, doing artificial photosynthesis at something like 200 times the efficiency of natural photosynthesis, without using land.

With cheap enough energy and more practice (descending the engineering learning curve) producing food this way may be profitable in 30 or 40 years. We can re-wild all arable land.

There are at least dozens and possibly hundreds of alternatives to lithium chemistry for batteries, that are nearly competitive with it. Some of them are better than lithium in some applications. Watch for CATL's sodium batteries.

But say it's worst case, none of the alternatives turn out to be better cheaper, and more environmentally benign: no problem. There most definitely is enough mineable lithium. There's a temporary shortage of lithium refining factories.

If we had to, we could get by with water, rock, iron, sodium, potassium, calcium, phosphates, carbon, aluminum, and trace amounts of other things. The minerals we need a lot of, we have a lot of.

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