[graeme]

That’s all well and good to say, but we currently have no system to do that.

What we ought to have is a carbon tax. Then if some activity such as bitcoin or ai or driving or flying uses carbon, you pay extra. Whereas if you manage to fuel your activities with nuclear/wind/solar you don’t.

There are loads of complexities to this but simply saying “consumption is necessary for riches” while ignoring that we have not managed to lower our carbon usage is not quite hitting the mark.

[colechristensen]

Carbon taxes aren’t necessary to give solar and wind an advantage. More than half of ~55GW new power generation capacity in the US this year is going to be solar.

> while ignoring that we have not managed to lower our carbon usage

We have in the US, both total and per capita. Carbon per person is down nearly 25% since 2000.

People seem to make up statistics in their heads to match what they think is going on.

[graeme]

World growth is the only metric that matters. USA offshored many industries which use CO2.

World carbon growth has not peaked as you can see here: https://ourworldindata.org/co2-emissions

CO2 is also most analogous to an overflowing bathtub. Lowering the rate would be great if we can get there, but what we really need is to get to zero new CO2 emissions.

We are a long way off from that so every new energy use worsens the issue until we get there.

[kragen]

if your bathtub is overflowing you should unplug the drain; atmospheric carbon capture is not cheap, but not infeasibly expensive either, and will surely be necessary

[graeme]

I agree, but you can only stretch an analogy so far. Unplugging a bathtub is free, whereas capturing carbon currently is more costly than the energy used to capture it.

[kragen]

taken literally you seem to be saying that there are costs other than energy involved in atmospheric carbon capture, which is too obvious to be worth saying; your capex and non-energy opex costs can be low but they obviously can't be zero or negative

do you mean more costly than the energy obtained by burning it, because that's a small edit that converts your statement into an assertion that's at least coherent

if so, no, the cost is about an order of magnitude smaller; though coherent, your assertion is still wrong

[kragen]

we do currently have a system to pivot to cleaner sources; it's the photovoltaic module industry, which has undercut the price of fossil-fuel energy by almost a factor of two in much of the world, though not in polar regions

[graeme]

Please see this chart of global co2 emissions. They have not stopped rising

We have a system for adding solar energy on top of carbon emissions but not for lowering carbon usage, yet.

https://fred.stlouisfed.org/series/M12MTVUSM227NFWA

[kragen]

they will continue rising until the late 02020s because ramping up pv production is a relatively slow process and because transport mostly can't be electrified without syngas or something similar

of course syngas will happen but it's not an overnight thing, especially if what gets adopted is hydrogen instead of something like fischer–tropsch-sourced diesel

[graeme]

As the original poster noted, energy is useful. Carbon won’t decline unless electric beats it for baseload, with batteries or somesuch.

Merely being cheaper won’t do it. As long as more expensive sources are useful, and as long as solar is supply constrained, no reason that solar growth would cut into carbon usage.

[kragen]

'unless electric beats it for baseload' seems like an error; perhaps you meant 'unless renewables beat it for baseload'

the cheaper/useful/constrained trichotomy seems like a similar error; supply constraints manifest as higher prices, and the usefulness of a fairly fungible commodity like energy is entirely relative to its price

pv with batteries is already cheaper than fossil-fuel sources in much of the world, and largely as a result, fossil-fuel consumption for electrical generation is already slowly dropping in much of the world; this has already resulted in a rash of bankruptcies of coal companies

overall fossil-fuel consumption is not dropping, but will be within a few years

[palata]

A photovoltaic industry that mostly depends on fossil fuels, doesn't it?

[kragen]

no, it mostly depends on energy

the production processes for the key materials involved, like silicon, aluminum, and glass, can use any convenient energy source

the exception is the carbon dioxide emissions from the carbon electrodes in aluminum smelting pots, but this is a tiny fraction of the total

[palata]

> no, it mostly depends on energy

Sure, and where does most of that energy come from today, and how do you propose we replace it? Because that's the whole point, isn't it?

> can use any convenient energy source

Sure. Right now it's mostly fossil though, and it's not like photovoltaic is even close to changing that. Of course if you assume a theoretical clean energy to build your photovoltaic, then that's clean (in terms of CO2), but if you have that clean source, why do you need photovoltaic in the first place?

I think that's a real problem that gets ignored too often: fossil fuels are limited, and we seem to be around peak production right now. So fossil fuel will go down, that's pretty sure. The question is whether we will be able to compensate, and it's really not a given.

[kragen]

most of this energy today comes from fossil fuels. i propose we replace it primarily with photovoltaic energy. i am not sure how this could have been unclear from my comments above. this transition is already happening and will be essentially complete within a decade

(supplemented where possible with wind, which is cheaper where it's abundant)

but it's irrelevant where the energy comes from today when we're talking about what pv production is dependent on. it's not dependent on fossil fuels. it's dependent on access to cheap energy, and it also provides that cheap energy; the energy payback time on pv production has been under two years for decades now

if your concern is that there will be no market for additional abundant cheap energy once current fossil-fuel generation has been displaced, you should probably stop worrying about that, because that has never been a problem so far in human history

oil extraction is indeed around its peak right now, but coal reserves would last another century or more at current extraction levels. the issue is that it would be bad to turn the planet into venus. currently the world is on a path to, as you say, compensate, but it's possible that a sufficiently large disaster could halt that process

cf. https://archive.is/KMsTT https://www.economist.com/finance-and-economics/2023/02/13/w...

[palata]

> i am not sure how this could have been unclear from my comments above.

It was clear. I am just saying that photovoltaic is very far from replacing fossil fuels.

> this transition is already happening and will be essentially complete within a decade

I guess let's see that. Also photovoltaic energy depends on the weather, it's not exactly something we can control (unlike fossil fuels or nuclear energy).

> that has never been a problem so far in human history

Well I think we can say that energy consumption in human history is largely correlated with fossil fuels, can't we? But I did not say that there is no market. I said that it's not clear whether we can make it work _at all_ without fossil fuels and without reducing our consumption.

> the issue is that it would be bad to turn the planet into venus.

Yep, but the biodiversity problem is not even related to climate change: we are destroying life on Earth just because we have the energy to do it. The fact that, on top of that, this energy is creating big problems that still have to happen (climate change) is just adding to the problem.

We should just drastically reduce our consumption, both because cheap energy is not a given for the future, and because we should care about not turning the planet into Venus, or Mars.

[andromeduck]

That convenient energy source needs to be stable, which most renewables are far from.

[kragen]

there are some advantages to it being stable, but even today, pv plus batteries is still cheaper than coal in much of the world

[palata]

If you ignore the fact that your pv panels plus batteries relied on fossil fuel for extraction/manufacturing/transport, right?

Now try to do all that without fossil fuels. Is that still cheaper, today? Pretty sure it's not (pretty sure it's not possible to do that with only pv energy right now, the infrastructure is just not there).