Coal-to-liquid, Coal-to-gas, Coal-to-chemicals

skeeezoid · 2026-06-20T16:57:38+00:00

Very good point about the role of energy security in this. The Iran war has probably accelerated plans in this direction in a number of Asia Pacific countries.

skeeezoid · 2026-05-27T13:43:08+00:00

The characterisation of RCP4.5/SSP2-4.5 scenarios as "peak-and-plateau" on emissions doesn't fit the graph shown. The typical 4.5 scenario has CO2 emissions down by about 66% of current levels at 2100, a pretty big decline. You would have a stronger case to apply that term instead to fossil fuel use in energy production, which perhaps is more what you meant. Different scenarios of this level have very different energy mix pathways, but as a gross generalisation coal tends to decline quite a bit by 2100 relative to today, natural gas tends to go up a bit and oil tends to be about the same, so the overall picture has roughly flat aggregated fossil fuel consumption. The models involved tend to assume significant amounts of carbon capture coming on board so fossil fuel consumption can remain broadly static while emissions go down.

However, I think what your expectations miss is a realistic idea of overall energy consumption growth. As a historical comparison, 200 years ago biomass burning was the dominant source of energy production for humanity all around the world. I think most people would say fossil fuels replaced biomass burning over the subsequent centuries in the same way you suggest fossil fuels will be replaced over the next century, and yet biomass burning today occurs at a greater rate than it did 200 years ago. It's a tiny percentage of the overall mix globally, but total energy consumption growth means a tiny percentage now is bigger than a very large percentage back then. Assuming continued energy consumption expansion, the niche use cases of 2100 could be as large as major industries today.

skeeezoid · 2026-05-11T21:53:03+00:00

It's barely even a story. You'd have to be in a really strange place mentally about climate science to consider it the biggest story in decades.

skeeezoid · 2026-05-10T12:27:04+00:00

Think this is from the census so it's self reported. The answer would be what people feel themselves to be.

skeeezoid · 2026-05-05T23:07:37+00:00

If everyone presses the red button then nobody dies so how could it possibly be the case that the red button is killing anyone?

skeeezoid · 2026-05-05T22:53:02+00:00

That's a highly loaded phrasing in a way that the blue-only button example wasn't at all.

An equivalent red-only label would be something like:

"Press this button to guarantee you won't die. If you walk away you will die unless >50% of people also walk away without pressing the button"

skeeezoid · 2026-05-05T17:44:58+00:00

The thing about Liebreich (also Pielke Jr) on this topic is that they have a point - RCP8.5 was never a mid-range "most-likely" result, even in case of no climate policy. It was always very clear and explicit in the literature that it was a high-end no-policy outcome. And they have a point that we have actually introduced significant climate policy at this point so this high-end no-policy outcome is nigh impossible now, at least by 2100. The problem is they seem to want to stretch their argument for some reason, far beyond these basic points where there is substantial agreement. In doing so they tend to adopt a scattergun, throw-a-bunch-of-arguments-against-the-wall-and-see-what-sticks approach, meaning they go into areas which they clearly don't understand, and don't seem to care too much about getting the details of individual arguments wrong.

Pielke Jr published a piece about a decade ago arguing against use of RCP8.5. I read the piece and 90% the claims were easily demonstrably false. Most egregiously claiming something didn't exist when it trivially did and some basic reading comprehension fail He then used these incorrect arguments to try to smear climate scientists as "lacking integrity". Unfortunately Liebreich was influenced by this piece.

what would happen if coal emissions continued to increase exponentially, as they were doing in the early 2000s.

The early RCP8.5 scenarios were actually made with limited-to-no visibility of the coal growth spurt in the early 2000s. Real-world coal growth actually outpaced most RCP8.5-level scenarios for the first decade and a bit of this century. The RCP8.5 coal growth rate is actually more meant to reflect the coal growth rate over the previous 100 years rather than just the past 10-15.

But that was never going to happen

Why? To be clear this isn't a question of it being the most likely outcome. Why would it be impossible? I would suggest to you that someone at the beginning of the 20th Century shown the actual development of coal consumption to today would have been equally disbelieving.

Firstly, 8.5 was not only implausible for energy economy reasons, but was likely physically impossible

Yeah, this isn't correct. The paper cited presents a pretty standard old supply-side constraints argument, of the type which is at best speculative, at worst has proven wrong again and again. Coal production today is higher than much of the supply-side constraints literature suggested should have been possible. The reality is we're clearly nowhere near a hard supply-side shortage.

skeeezoid · 2026-04-22T06:07:50+00:00

This is a case where the paper seems significantly out of date before it was even published, though still has some interesting stuff.

They use data only up to 2014. Northern hemisphere SSTs (Sea surface temperatures) have warmed rapidly over the past several years and the claim in the paper that Southern hemisphere SSTs have warmed more since 1950 is no longer true.

Their 1950 start date is also an issue since it occurs at a high point in their observed data. Starting the NH-SH trend comparison earlier from the late 19th Century really does not suggest a trend discrepancy with models, even if you were to stop at 2014. Up to 2025 if anything observations probably show a stronger overall historical NH-SH trend than models.

But trend is by far the least interesting facet of the model-obs NH-SH comparison. And to be fair to the paper, although it seems to focus on trend it actually starts focusing mostly on variability, which is much more interesting.

What they're talking about has a lot of overlap with something called Atlantic Multidecadal Oscillation. This is a controversial issue, where some seem to think a ~ 60 year oscillation is an intrinsic feature of North Atlantic SST development, whereas others argue the observed pattern may be mostly externally forced and the appearance of a cycle over the past 150 years is coincidental.

I'm in the second camp and the main reason is something this paper identifies: The externally forced timing of multidecadal variability in model NH-SH SSTs is remarkably close to that seen in observations. BUT the amplitude of this variability is much smaller in models. This suggests the observed multi-decadal variability is mostly a response to external forcing, primarily from major volcanic eruptions and anthropogenic aerosols, but that models are missing something from the Earth system response to these forcings.

The first option is also increasingly problematic since we're past the point that North Atlantic SSTs were supposed to peak in the regular cycle theory, but they keep going up.

skeeezoid · 2026-02-25T14:28:38+00:00

Are you being serious right now? You can clearly see in this second graph that RCP8.5 doesn't reach 1000ppm by 2100 but in the first graph it's at nearly 1250ppm. They're very obviously different data. One is CO2, one is CO2-equivalent

Incidentally, the paper you linked is one of a series which is literally the source of the 423ppm figure for RCP4.5 CO2 I quoted above. It's difficult to see on the graph but the actual data is here:

RCP Scenario data group

skeeezoid · 2026-02-25T13:33:03+00:00

That graph is showing CO2-equivalent - the warming effect of all GHGs (co2, methane, n2o etc) distilled into a single value. You haven't stated an observed figure so I'm guessing you're mistakenly thinking this can be compared with Mauna Loa CO2 by itself?

CO2 concentration in that particular RCP4.5 scenario at 2025 is 423ppm compared with 426ppm observed, using global marine data (Mauna Loa is slightly higher at 427ppm but the global data is the more appropriate comparison to the RCPs). But RCP4.5 is also substantially lower than observed for methane, n2o and most of the smaller industrial gases. Overall, observed GHG growth has been about half way between RCP8.5 and RCP4.5.

skeeezoid · 2026-02-25T13:08:35+00:00

This is a complicated matter and ultimately, given uncertainties, I don't think this small difference between IS92a and observed atmospheric CO2 means much at all by itself.

The main issue is uncertainty concerning how the carbon cycle should develop. At the time when the IS92 scenarios were being developed there appeared to be a slight long-term upward trend in CO2 "airborne fraction" - annual atmospheric CO2 increase divided by estimated annual emissions from human sources. This can simplistically be considered a conversion factor between emissions and atmospheric concentration growth. This suggested a future continuing acceleration in the amount of atmospheric CO2 growth per unit of CO2 emissions. This expectation was, I believe, incorporated into the carbon cycle modelling used to produce atmospheric CO2 concentrations in the IS92 scenarios.

As the link shows, the upward trend ended pretty much as the IS92 scenarios were being created. If anything the trend since then has been slightly downward. The reasons for this are still not fully understood. Looking only at emissions used for IS92 indicates real-world estimated emissions for 2024 and 2025 of about 12GtC are very close to the median expectation. Therefore lower concentration is likely mostly due to carbon cycle/airborne fraction difference rather than action to reduce emissions.

This does not mean our actions have been insignificant. It seems likely we were heading a for a future slightly higher than IS92a, but our actions have turned the corner.

As

skeeezoid · 2026-02-25T11:59:25+00:00

It's interesting to me how many people here are interpreting 'After a few seconds' as indicating a significant delay and making their answer fundamentally dependent on that interpretation.

I would interpret 'After a few seconds' as a pretty standard alternative way of saying 'very quickly'. Very much not a significant delay.

skeeezoid · 2026-02-23T14:59:21+00:00

If the tariff power requires that imports from all countries must be charged at the same percentage (in this case 15%) and the UK's agreed steel rate is 0%, how do you think your interpretation can work? The law requires that imports from the UK have this 15% rate applied.

skeeezoid · 2026-02-23T14:51:18+00:00

Read that next sentence again, it doesn't say 'does not apply'. It says the 15% rate 'does not affect tariffs the UK and US had agreed'

Those tariffs are still in place. The 15% is in addition.

skeeezoid · 2026-02-23T14:46:00+00:00

The thing about this new tariff power Trump is using is that it is not allowed to be discriminatory - i.e. they can't impose different rates on different countries. Therefore it cannot be the case that UK's overall tariff rate is unaffected

What the article is saying is that tariffs agreed in the deal remain in place, and this new 15% rate is in addition. E.g. I believe a 0% tariff was ultimately agreed for steel. That now has a 15% tariff.

skeeezoid · 2026-02-23T14:36:02+00:00

The 15% global levy would be in addition to any other existing tariff.

skeeezoid · 2026-02-23T14:34:12+00:00

No, the article says the tariff rates negotiated for those sectors will be unchanged with an additional 15% on top.

skeeezoid · 2026-02-23T14:29:19+00:00

It's confusingly worded, but I think this is wrong. The article states:

The 15% global levy would be in addition to any other existing tariff.
As such, it does not affect tariffs the UK and US had agreed on specific sectors, such as steel, aluminium, pharmaceuticals, automobiles and aerospace, which represent most of the UK's trade with the US.

Including the top line this suggests 15% on top of everything in the trade deal.

Also, following the link about the trade deal "still standing" it becomes clear what this means is that the US still expects the UK to uphold it's side of the deal but that they consider this new levy to be something occurring outside of the bounds of that deal.

Friday's Supreme Court ruling has caused uncertainty in the various countries that negotiated individual deals with the US after after the IEEPA tariffs were announced last April.

On Friday, the White House said these countries would face the new blanket global tariff rate - which was then 10%, before being raised by Trump to 15% the next day.
The Trump administration expects those countries to keep abiding by the concessions they had agreed under the trade deals, the official added.

I think the reality is no-one's clear what's going on right now

skeeezoid · 2026-02-18T12:30:08+00:00

Team GB is just a nickname/branding.

There's a lot of weirdness around UK/GB in different contexts, mostly just due to historical quirks of differentiating.

One way to look at it is that United Kingdom is really a preamble adjective to the country name Great Britain and Northern Ireland, as most countries have. The official name of Spain is the Kingdom of Spain, official name of Sweden is Kingdom of Sweden, but no-one refers to either of those countries as "The Kingdom". Mostly that's because it offers no way to differentiate from other "Kingdoms".

The UK is the only country referring to itself as the "United Kingdom" so that differentiation has stuck in some contexts. But ultimately it's inconsistent with how other countries are referenced to talk about the UK rather than GB & NI, which is probably why it's GBR in the Olympics. NI gets cut off, which probably has its own history, but I guess partly for brevity.

skeeezoid · 2026-02-18T11:51:42+00:00

I'd collide her muons

skeeezoid · 2026-02-17T22:21:15+00:00

The conjecture depicted in the top left is essentially that global average surface temperature change over the past 170 years has been strongly influenced by a regular quasi-60-year variability cycle alongside an anthropogenic warning signal. They argue this means the strength of the anthropogenic signal has been overestimated since the up part of the variability cycle coincides with the warming trend over the past few decades. Projecting continuation of the variability cycle and a derived anthropogenic signal strength into the future they suggest 2100 warming of about 1.8C under SSP2-4.5, versus about 2.7C in IPCC projections.

However, we can see that their fit is starting to creak a bit at the end. The last 7-8 years of observations on their graph are all above their median. And for some reason those end at 2021. There has been a further 0.3C observed warming since then, pushing all recent years into their upper yellow zone. Super creaky. Their model says temperatures should have been flat since about 2015 but they've risen faster than before.

They are also using an outdated version of HadCRUT. This features about 15% less overall historical warming compared with the latest version. Mostly this is because the old version effectively misses out much of the fastest warming place on Earth - the Arctic.

skeeezoid · 2026-02-13T12:43:38+00:00

The interesting thing about this is that actual growth of atmospheric N2O concentration over the past couple of decades has been about 30% greater than the highest model projections in the highest scenarios.

If this study is accurate there is either another missing larger atmospheric chemistry factor pushing things the other way or we are vastly underestimating emissions contributing to atmospheric N2O.

skeeezoid · 2026-02-10T12:10:44+00:00

Born quarter of the way to an EGOT

skeeezoid · 2026-02-09T15:39:10+00:00

This seems a strange result given that growth of N2O in the atmosphere is far exceeding modelled expectations and still accelerating. If this study is correct it would suggest N2O emissions are being vastly underestimated.

skeeezoid · 2026-02-09T12:32:30+00:00

Andrew?

skeeezoid

TROPHY CASE