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Comment by graeme | Hacker News Reader

>why THIS time things are different.

Because all growth since Malthus' time has been due to the use of stored Carbon energy. Malthus' observations had been largely true until then.

Maybe we'll figure out some way to replace our stored carbons inputs in a way that lets us keep the same energy surplus.

But, that's the short answer for why things may be different: the past 200 years have been a historical aberration. The fact that an effect takes a while to work itself out doesn't mean that that effect is nonexistent.

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> Maybe we'll figure out some way to replace our stored carbons inputs in a way that lets us keep the same energy surplus.

We already have: unfortunately, massive and pervasive scientific illiteracy, often abetted by the same people complaining about population growth and carbon-based energy, has prevented us from making full use of nuclear power. If you'd like to fix the energy problem as quickly as possible, without waiting for breakthroughs in solar or battery storage or fusion, it's Greenpeace you need to talk to.

You don't even need nuclear power, we could get all the energy we currently need from geothermal sources. It's not exactly renewable but it's non-polluting and there's enough energy to last us for a long long time to come (I can't remember the exact figures, I'll look it up).

That said, it's good to diversify energy sources (so long as they're non-polluting), and I can see some potential benefits for thorium-based reactors.

The main reason we haven't moved away from fossil fuels more quickly isn't due to blocking nuclear, it's due to short-term profit-led thinking.

EDIT: "The MIT report estimated that over 200 zettajoules (ZJ) would be extractable, with the potential to increase this to over 2,000 ZJ with technology improvements – sufficient to provide all the world's present energy needs for several millennia."

https://en.m.wikipedia.org/wiki/Geothermal_energy

Plenty of time to develop renewables and nuclear fusion, no?

"present energy needs for several millennia" means actual energy needs is a much, much shorter timespan assuming we continue our exponential trend of energy use.

Doesn't matter, as long as it buys time to develop renewables and nuclear fusion.

> continue our exponential trend of energy use.

I think that trend has had its run - we're not brute-forcing every industrial process any more, getting clever about energy use is all the rage now.

> You don't even need nuclear power, we could get all the energy we currently need from geothermal sources. It's not exactly renewable but it's non-polluting and there's enough energy to last us for a long long time to come (I can't remember the exact figures, I'll look it up).

Nuclear is non-polluting too. It's probably the greenest form of energy available to us per kWh if you count everything up. Diversification is a good idea though.

> The main reason we haven't moved away from fossil fuels more quickly isn't due to blocking nuclear, it's due to short-term profit-led thinking.

There are two aspects here - one is that we haven't moved away from fossil fuels due to "short-term profit-led thinking", or as it is formally known (if you count profits in dollars), the market economy. But the second aspect is that as we slowly move towards other sources, we're moving away from nuclear - and that happens because of FUD and politics (which is also "short-term profit-led thinking").

I agree that nuclear has its place but...

"we're moving away from nuclear - and that happens because of FUD and politics (which is also "short-term profit-led thinking")."

... I don't agree with that. I'd even go as far to say the opposite is true, one of the biggest issues with nuclear fission is the long life of nuclear waste, it's only when you have a long term view that it becomes a problem.

Again, there are ways around this. From what I understand it's possible to reuse nuclear waste (are the power plants that do this known as breeder reactors?).

Another big issue with nuclear fission is the other, more destructive use for it. Building reactors all around the world could aid the development of nuclear weapons. Again, that sort of insight isn't exclusively based on a short term view. Again, there could be ways around that. Am I right in thinking that thorium is harder to use in the process of producing plutonium?

At most you could say about short term thinking is that the cost and lead times for producing new nuclear reactors seems fairly high, which would put off some investors.

Nuclear waste is pure FUD, I'd say it's one of the most successful examples of it in history. It's created in small quantities, it's much less dangerous than many waste material created by the chemical industry, we know how to manage it, and properly sealed it's harmless if left alone. The amount of attention nuclear waste gets is nowhere near commensurate to the danger it poses; it's seriously, seriously overblown. I'd wager asbestos is more dangerous.

The proliferation argument is a good one, and it limits available solutions. Some thorium-based designs are indeed more difficult to hijack for production of nuclear weapons.

Incorrect.

Tom Murphy (author of the top-level article here) has done an analysis of global geothermal potential. It comes up far short of present or forecast energy demands:

http://physics.ucsd.edu/do-the-math/2012/01/warm-and-fuzzy-o...

Note that even tapping geothermal only for thermal uses still falls far short:

The average American household used 80 thousand cubic feet of natural gas in 2001 (apologies for old data and Imperial units). The gas is predominantly used for heating of one form or another: house, water, and food. 80,000 cf translates to about 800 Therms of energy per year, or 2700 W of continuous thermal power. Using our number from before that the mantle generates 7×10−12 W/kg, the average American home would need a rock mass of 4×1014kg, or a cubic volume 5 km on a side at a crustal density of 3.3 times that of water.

You might also want to check the IPCC's SRREN renewables energy report which has more deets on a large slew of renewable energy options.

From the article you linked to...

"Still, if we don’t care about sustainable use of geothermal, we can just keep drilling new holes to deplete one region after the other. In this sense, we could evaluate the thermal endowment in the upper 5 km of crust under land. The average temperature in this layer is about 60°C above the surface value, so that each cubic meter (3300 kg) contains 180 MJ of thermal energy. Summed over 1.4×1014 m², we get about 1026 J. This is 250,000 years of our global appetite. A quarter-million years might seem close enough to indefinite that we’re willing to call it sustainable. Truly it is a substantial endowment. It’s the practical considerations that hold us off from rushing into this resource."

There are some practical issues to overcome before geothermal could take a bigger share of the energy mix, but they're being worked on. Whilst I don't believe we should ever rely on one energy source, not even when we have nuclear fusion, I still think that geothermal has enough potential benefits to make it unwise to rule out whilst we still need to move away from polluting sources of energy.

Here's one idea for improving the practicalities of geothermal:

"Bhargava’s other hobby is tackling the world’s dependence on polluting fossil fuels with geothermal energy. His twist? Use a grapheme cord, which is stronger than steel and an impressive conductor of heat, in lieu of the usual steam-and-chemicals to gather and distribute underground heat. By his estimate, geothermal energy like this could replace 85 percent of fossil fuels."

http://energyefficiencymarkets.com/quick-energy-efficiency-n...

I'm a big fan of turning to empirical data where it's available. One case in point is the "Habanero" well dug in Australia as a pilot for an enhanced goethermal field. This is a nonsustainable proposition, with individual wells having a fixed life I don't recall offhand, though it's < 40 years.

The project's been plagued by multiple setbacks, for which some of the most candid accounts come from the company's own investor filings with the Australian government, though the upshot is:

* The whole durned thing done blowed up. There was a steam explosion which, putting things mildly, proved a substantial setback. Fortunately no one was killed.

* Power output of the pilot project has been scaled back tremendously. Again it's been a few years since I looked at this, but actual achieved output was 1/50th initial estimates.

* Costs were tremendously higher than initially anticipated. For achieved output, $30,000/kW, vs. about $4,000 kW for solar (less today).

* Schedule overruns, even accounting for accidents, were on the order of years.

Ah, turned up my earlier article, you can see that here:

https://reddit.com/r/dredmorbius/comments/1wpa90/how_not_to_...

Nuclear energy is also technically fossil, it wouldn't last much longer than fossil fuels if employed on the same scale. What prevents the use of nuclear energy are worries about it being used to make nuclear weappons, which means that being dependent on nuclear power means being dependent on one of the nuclar power countries because you need to buy fuel from them.

Solar energy is on the other hand for all practical puposes inexhaustable. The equivalent of ALL fossil fuels hits Earth every few days. It won't run out in foreseable future and if it will, we are done for anyway.

I'm for nuclear power, and think it's the height of idiocy for groups opposed to global warming to have supported the removal of nuclear before coal.

I was just pointing out that there is a cogent rationale for why this time could be different. Perhaps we could replace fossil fuels, but we haven't, yet. And until we do we're still in the same 200+ year energy cycle that started around Malthus' time.

The poster I was replying to seemed to think there was literally no reason that Malthus might be right. He's not certainly right, but he's not certainly wrong yet either.

When we run out of stored carbon energy we will probably switch wholesale to splitting atoms and harnessing the energy of the sun. Alternate energy is a matter of how soon, not whether.

I tend to agree with this view. While population growth definitely comes at a cost it also provides us with our most valuable resource: human intellect. Perhaps this is the perfect time to tap our earth's carbon battery to propel us into the next orbital of energy production and consumption. Or perhaps we are not socially and culturally smart enough to make efficient use of this energy and we will exhaust our surplus and perish, another evolutionary footnote of history. Either way, I doubt we have the power to stop this juggernaut now so might as well assume (and try to achieve) the optimistic option.

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