The path to decarbonization

by John Q on November 30, 2020

Over the fold, another draft section of the climate chapter of Economic Consequences of the Pandemic. As always, comments, compliments and criticism appreciated

The response to the pandemic, in the US and many other countries, has been less than successful. But even leaving aside the disastrous impact of the Trump Administration, it must be conceded that the pandemic posed an incredibly difficult challenge. When it broke out, we had no cure, no vaccine and a very limited understanding of the virus and the way it was transmitted. Now that vaccines are entering production, and given competent government, we can hope for much better outcomes in the future.
The contrast with the climate crisis is striking. We have had decades of warning and devoted millions of hours to researching every aspect of the problem. Yet, emissions are still increasing. This failure has come despite the fact that we have have nearly all the technology to decarbonize the economy, at relatively modest cost, and with little disruption to our daily lives.

To stabilize the global climate with less than 2 degrees of warming will be a massive task. It will require not only the elimination of nearly all greenhouse gas emissions in developed countries by 2050 but active measures to remove greenhouse gases from the atmosphere. To see what needs to be done, it’s useful to start with the big picture. At present, around 85 per cent of all primary energy is generated by burning oil, gas and coal. Of the remaining 15 per cent, hydroelectricity and nuclear power (which are unlikely to grow substantially) account for 10 per cent. Solar PV and wind account for only 5 per cent.

The process of decarbonizing energy supply is already underway, but the pace of change is far too slow. Technological progress over the last twenty years has drastically reduced the cost of two carbon-free energy sources, solar photovoltaics (PV) and wind power [fn. I will use the standard term ‘renewables’, although it reflects an obsolete perception of the energy problem, dating back to concerns about the possible exhaustion of ‘fossil fuels’ like oil and coal. When dealing with climate change, the sooner low-cost carbon-based resources become scarce, the better]. Other potentially promising options including geothermal energy, tidal power and biofuels, didn’t work out and have been quietly forgotten (I’ll discuss nuclear power a little later). More recently, improvements in battery technology have effectively eliminated the variability problems associated with solar PV and wind, and have also undermined the case for gas-fired power as a ‘bridge’ to carbon neutrality.

Improvements in battery technology are crucial to the next major step in the process, electrifying transport. Electric cars, buses and trucks are already on the market, and have a lifetime cost of operation only a little higher than that of comparable petrol and diesel vehicles. A modest expansion of existing subsidies would be sufficient to make electric vehicles cheaper. However, the shift to electric vehicles can yield a substantial reduction in emissions only if electricity generation is already largely decarbonized.

The last important piece of the puzzle is hydrogen. In principle, hydrogen produced by electrolysis (splitting water into hydrogen and oxygen) can replace carbon-based fuels in most industrial uses. Examples include the replacement of blast furnaces for steel with DRI and the production of ammonia, the main feedstock for a variety of chemicals, which is currently made using hydrocarbons. Large-scale investment in the production and use of ‘green hydrogen’ (as opposed to current production methods based on lignite) is just beginning, but could be accelerated rapidly given the political will to introduce the necessary supporting policies.

The moderately good news is that the supply of energy from solar PV and wind is growing at around 10 per cent per year, which implies a doubling every seven years. If this trend were were consistently until 2050, and total energy demand was unchanged, the carbon-free share of energy demand would by above 60 per cent.

The positive trend was driven almost entirely by the electricity sector. Coal-fired electricity generation is in sharp decline in most developed countries. This process was already underway before the pandemic,

BP Statistical Review states that in 2019

Renewables provided the largest increment to power generation ( 3 4 0 TWh), followed by natural gas (220 TWh). These gains came partially at the expense of coal generation which fell sharply (-270 TWh), causing the share of coal in power generation to fall by 1.5 percentage points to 36.4% – the lowest in our dataset (which goes back to 1985).

Another way to look at the aggregate numbers is to ask what changes would be need to begin a sustained reduction in energy-related emissions

The BP Statistical Review notes that, in 2019, clean energy accounted for 40 per cent of the growth in primary energy. One way to think about this is that if the rate of additions of renewables were doubled, and the rate of growth of primary energy demand were reduced by 20 per cent, all growth in primary energy would be delivered by clean energy. Given that gas would expand at the expense of coal, this would imply the end of growth in energy-related emissions.

The shift away from coal has accelerated during the pandemic, particularly in less developed countries. Coal-intensive energy strategies have been abandoned or sharply modified in several countries, including Bangladesh, India, the Phillipines and Vietnam. At the same time, China, South Korea and Japan have committed themselves to a zero net emissions target (2060 for China, 2050 for the other two).

Commitments to decarbonization have not, as yet, been matched by concrete policy measures. But the goal of zero net emissions by 2050 is entirely feasible and would, if achieved, stave off most of the worst consequences of climate change.



Omega Centauri 11.30.20 at 9:56 pm

Primary energy, if I have it right, is the gross energy contained in fuels. To a thermodynamics or physics person, this is low quality energy, and much of it is lost in the conversion to high quality energy -mainly mechanical work or electricity. Most renewables directly generate “high quality energy”, mainly electricity, without the need for conversion. So a single BTU of primary energy doesn’t require a BTU of renewables for its replacement, but rather a fraction of a BTU typically 30-40%. Also primary energy is often used for heating, but the use of electricity to run heat pumps can generate several times as much usable heat than its energy content. This is yet another reason that we don’t need to replace primary energy with renewables on a 1 to 1 basis.

There is a lengthy article on the efforts to scale up green hydrogen.


Kiwanda 12.01.20 at 2:07 am

Other potentially promising options including geothermal energy, tidal power and biofuels, didn’t work out and have been quietly forgotten

Re geothermal, some recent positive developments.

improvements in battery technology have effectively eliminated the variability problems associated with solar PV and wind,

Some, but seasonal scale is tough; green hydrogen (or ammonia) might help there.

If this trend were were consistently until 2050,

Typo. And: given that building new wind and solar is now cheaper than using existing fossil-fuel plants in many places, the trend may well accelerate.


Alan White 12.01.20 at 2:44 am

This has bothered me for a long time, and I confess it’s just my unresearched worry: if cars and such go largely electrical, what are the carbon and other related costs in terms of long-term manufacture and disposal/recycling? And clearly (it seems to me) the nature of all this as a solution is tied to making electricity largely through non-carbon sustainable means. Sorry if I’m a dolt about all this.


John Quiggin 12.01.20 at 5:13 am

A point I need to stress: We are already experiencing serious damage from global heating, and, whatever we do, things will get worse over the next 30-50 years, maybe longer. We don’t have a choice between “damage” and “no damage”, but between “damage” and “much worse damage”


Alan White 12.01.20 at 5:25 am

John @ 4–thank you and I guess I knew that too, given the massive scales of consumption we’re talking about, particularly in so-called first-world countries. But bumpkins like me are pretty much at sea about how to macro-assess what strategies can push us forward to a more hopeful future, and that was the source for my battery/electricity worries. Just tonight I watched David Attenborough’s semi-autobiographical warning about declining biodiversity on Netflix, and although he ended on a hopeful note given sufficient activism, the relatively slim Biden victory is just one indicator that we may be far from that. But as I’ve said many times before here–thanks for your excellent posts.


Hidari 12.01.20 at 6:47 am

‘But the goal of zero net emissions by 2050 is entirely feasible and would, if achieved, stave off most of the worst consequences of climate change.’

Er….yeah. Sorry to rain on everyone’s parade, but this weasel phrase (and it is a weasel phrase) ‘zero net emissions’ is something we will be hearing about a lot in the next 20 years. Unfortunately it is, essentially a propaganda term, the real meaning of which is ‘let’s do next to nothing for the next 20/30 years and then panic when we realise we have done nothing.’

Morally (and remember carbon dioxide is, at the end of the day, a poison….as will be indicated by the fact that most CT readers will have electronic detectors in their houses to detect emissions of this poison) the problem with the idea can be indicated by the use of a somewhat crude analogy (look away, snowflakes!).

Imagine that I kill 3 people, and then go away somewhere else and impregnate someone and then ‘produce’ 3 babies…and then, when brought to trial, I say ‘Well my defence is that I killed 3 people, yes, but net deaths were zero! Not guilty, your honour!’.

You quickly spot the flaw here. But, remembering that (human produced) CO2 is a poison, which does nothing except kill people, this brings home that the key point is not net emissions. The key point is the gross emissions. The moral crime is introducing it into the atmosphere in the first place, and whether or not I later ‘compensate’ for that is irrelevant.

Practically, there are even more problems.

‘A net-zero target is met… when residual emissions are offset by CO2 removals. ‘

But This requires the development of ‘ “negative emissions technologies” (NETs).’ to remove the CO2 from the atmosphere.

‘But the main problem is that most NETs are still only prospective technologies – they do not exist as large-scale socio-technical systems ready for deployment’.

Please remember that, as of now, NETs are literally Harry Potter ‘technology: ‘Expelliaumus!’. They literally don’t exist, as large scale, viable technologies. It is possible that they will exist in 20/30 years in the future, in which case we can have a discussion about them. But right now, they don’t, and there is no reason other than blind faith to think they ever will. There is still less reason to think that these technologies will run as advertised, that they will be cost-effective, and that they won’t have side-effects.


Zero net emissions is probably is not enough (and is probably not achievable within the timescales necessary anyway).

We need Zero Gross Emissions by 2050. The amount of CO2 it is safe to produce is ‘zero’.


John Quiggin 12.01.20 at 7:46 am

@Hidari A 2050 zero target implies no new coal fired power projects starting now, hence no new coal mines, and no new ICE cars after about 2035, which means a big retooling starting now.

Possibly some governments announcing 2050 zero targets haven’t worked this out yet. We have to make sure the logic works its way through, for example with the imposition of border adjustments on cheats (promised by Biden, and one of the few points where the Trumpists will back him).

As regards net removal, tree planting is the obvious low-tech option. And because methane is a potent greenhouse gas with relatively short residence time, stopping emissions means net removal (ending fracking would go a long way here, and there may be low cost options with paddy rice and ruminant livestock).


Hidari 12.01.20 at 8:48 am


No one is denying that tree planting is a good thing. But it’s one thing to say that it’s a good thing. It’s quite another to say that tree planting can, in any meaningful sense, solve this problem.

To ask just some basic questions:

‘how realistic are the study’s estimates of how much carbon can be sequestered through reforestation? How long will this approach take to make a dent in atmospheric carbon concentrations? Can grasslands and savanna ecosystems sustain increased tree cover? How might converting non-forest land to forests compete with food production? How much time, money and resources will it take to implement a global forest restoration of this magnitude? How do the costs of adopting such a climate mitigation strategy stack up against its potential benefits? How much carbon would be released to the atmosphere by restoring forests? How will global climate models respond to a massive forest restoration? Will an Earth with a billion hectares of new forests actually be cooler?’

Obviously these questions might have positive answers, although the progress, or lack of it, in the fight against climate change over the last 20/30 years should give us pause here.

One key point about putting the deadline for zero net emissions at a time which seems a long way away (although, obviously….it really isn’t), i.e. 2050, is that it psychologically prepares one for a thought process which works like this: ‘We can continue to produce as much CO2 as we want, and then by 2040 all the NETs will be available and will suck all the CO2 out of the atmosphere and everything will be fine.’ In other words, the risk is that it’s simply a ‘license’ for politicians to do essentially nothing for the next 20 or so years.

This is why Extinction Rebellion are entirely correct in calling for net zero by 2025. Not that this will happen: of course it won’t. But the shorter ‘deadline’ makes it clearer to everyone that we have to act now, and waiting for NETs or (at the moment, hypothetical) replanting movements to get started is just time wasting.

Gross CO2 emissions must go down: to zero. That is the key point. Everything else is just hand waving.


bad Jim 12.01.20 at 9:11 am

You’re giving short shrift to geothermal energy. Apparently only California (among US states) is using it to appreciable extent. It’s actually almost universally available using what are now conventional drilling techniques. It says here.

Contrariwise, there’s a flip side: geothermal cooling. A few meters below the surface it’s reliably cool, a giant heat sink, which makes passive air conditioning feasible with considerable investment, probably not a plausible retrofit for most properties.


Stephen Luntz 12.01.20 at 10:21 am

I’m not sure I agree about tidal being forgotten about. It seems to be undergoing the same exponential growth in scale/decline in price solar and wind have. It’s just starting from further behind.

Given some of the best sites for tidal are in places that are very bad for solar (Scotland, Wales, Maine, Canadian maratimes) I can see it providing a substantial amount of power for those places if it proves cheaper than the cost of stored wind power.

On a global scale that will only be about 1-2% of electricity production, but it’s significance could be greater than that. If tidal allows those places to go 100% low-carbon more quikly than relying on solar, wind and batteries (plus remnant nuclear) at a price people will accept, the influence that could have on global debates could be important.


Tm 12.01.20 at 1:15 pm

The Amazon continues being destroyed at record rates. I agree that decarbonizing the energy economy is entirely feasible, and would be much farther along were it not for the criminal policies of Trump er al. But can we prevent the destruction of the forests?
(Not all forests are shrinking but some of the most ecologically valuable and sensitive are).


Jim 12.01.20 at 2:47 pm

–Hidari, that electronic detector in your house is for carbon monoxide.


Omega Centauri 12.01.20 at 4:41 pm

The thing that disturbs me about net-zero 2050, is that it is way too late. Now if we push for say 80& reduction by 2030, we would be OK, but most likely those pledging for 2050 plan to go slow for the first decade, and we can’t afford the consequences of that.

Alan @3. While everyone driving 2ton vehicles is not sustainable, EVs are not as bad as you might think. EVs are much simpler, and are expected to last longer than ICE cars. Also batteries can/will be recycled. So compared to current practices are an major improvement. The same battery/motor technology is enabling inexpensive last mile personal transport, ebikes, E-scooters are now quite viable, and have an order of magnitude or more lower environmental cost. So if we can make roads and parking safe for such a significant downsizing of much of our local transport can proceed.


steven t johnson 12.01.20 at 5:31 pm

Hidari@6 tells me I am a poisoner for breathing. Massive population reduction would sharply decrease the poisoning of the planet. But that’s only a start. Sterilizing the topsoil to prevent carbon dioxide production by fungi decomposing dead plants and animals would no doubt be very helpful in preventing the production of such poisons.

Joking aside, the notion that “green hydrogen” is truly meaningful is not a well-understood fact among the laity.

“This failure has come despite the fact that we have have nearly all the technology to decarbonize the economy, at relatively modest cost, and with little disruption to our daily lives.”

This is doing an awful lot of work here. Restricting land use so that forests and other carbon dioxide fixing plants would be a major disruption of land use policies, revising land values, with all the manifold implications for banks’ real estate assets and tax revenues for government. A much overlooked source of carbon dioxide fixation, seas waters, especially near coasts, should be restored by careful management of effluents from land. But again, that too would be a major disruption of economic affairs as constituted.

Most of all of course, the question is, given the unquestionable commitment to fundamentally private control of capital investments, who is going to profit from any of these measures? Transferring spending from armaments to reconstructing the energy infrastructure no doubt would help pay, but the need for armies to defend property (aka the “nation”) won’t be solved by a carbon tax.

A sustainable energy economy is one that is in many respects a stationary economy. Free market economies are not even stable (crass as it is to say,) much less stationary. Private property in the means of production is the very meaning of freedom. After all, what is freedom but the right to buy what you can afford, and otherwise do what you wish with your property? (Sorry about slipping back into the jokes at the end.)


stephen harrod buhner 12.01.20 at 6:21 pm

Your analysis is very good and makes sense; I have no quibbles with it per se but it, as usual with the global warming/climate change discussion, it fails to be ecologically based. This is a serious problem; in many respects global warming is the least of our problems. The oil companies are quite aware that their time is coming so they have long range plans to move in different directions to keep profits high. While it is true that reduction of hydrocarbon use for energy will help the global situation, it won’t stop what is occurring. To slightly shift the focus to a more ecological orientation. Hydrocarbons are used to make most of the pharmaceuticals that are used worldwide; they flow through the human population in the trillions of tons, entering the earth’s microbiome where they act to destabilize ecological homeostasis. This is on a far grander scale than antibiotics disturbing our gut microbiome. Our bodies are not dissimilar to those of the other life organisms on this planet and as these pharmaceuticals flow through our bodies and manufacturing activities into the waste stream they alter physiological functioning of every organism there is. The problems from plastic production, unlike pharmaceuticals, are being more fully recognized but there are no plans in place to stop plastic production. What is true, but that no one will say aloud, is that all chemical manipulation of hydrocarbons needs to completely cease. This is a serious problem, obviously, as human civilization, as presently constituted depends on that manipulation. More directly, when talking about alternative forms of energy production, what is nearly always left out is the ecological impact of manufacturing solar cells and wind power generators AND how they are going to be recycled once they are past their useful lifespan. As John Muir once said, “When we try to pick out anything by itself, we find it hitched to everything else in the Universe.” Looking at any of our problems in isolation and then creating technosolutions that are themselves looked at in isolation is a serious mistake. This is how we got into this mess to begin with. Each suggested solution has to be seen from the perspective of whole earth systems other wise the unforeseen side effects of what we propose, as has been done by our ancestors, merely leaves them to our children and their children to solve.


Alan White 12.02.20 at 2:28 am

Omega @13–thank you for that. One concern is that many scenarios for improvement require large-scale mind-shifts about things like large engine muscle-cars (though I’ve been impressed with the stats of the 0-to-60 for some electrics) and big SUVs and the like, and in the US I can’t see that changing soon enough to get gas-burners out of the way. In some ways this issue is about generational change–people like me who actually rebuilt motorcycle engines will naturally feel (yes feel) like their familiarity trumps (sorry) the oddness of electric. That is a prejudice that is very powerful–and the only way I see its ebbing is by the literal death of those who hold it. And the increased life-spans of my generation thus work against carbon deadlines.


John Quiggin 12.02.20 at 3:09 am

Thanks for lots of useful comments. I’ll take another look at geothermal and tidal, and think about everything that’s been raised here.


Kiwanda 12.02.20 at 3:18 am

Re 2030.


Our global EV forecast is for a compound annual growth rate of 29 per cent achieved over the next ten years: Total EV sales growing from 2.5 million in 2020 to 11.2 million in 2025, then reaching 31.1 million by 2030. EVs would secure approximately 32 per cent of the total market share for new car sales…

Motley Fool:

Take all of this into consideration, and the United States could generate close to 50% of its total electricity from renewable energy sources in 2030. Add in nuclear power, and close to 70% of American electricity could be generated from zero-carbon sources, up from 40% today,

For these, and for the heating of buildings using heat pumps (possibly geothermal), the technologies are here now, and converting now would save money in the long run, here ignoring the climate and health benefits. It’s the upfront costs that are the problem. It’s a clear situation for government investment and intervention. That’s happening, a lot more is needed.


Hidari 12.02.20 at 7:14 am

Lots of irrelevant, ‘nitpicky’ responses, along the lines of ‘there are no CO2 detectors’ (er, yes there definitely are) and ‘CO2 is not a poison’ (er, yes, it definitely is).

But the key point is: is net zero a useful term to use in terms of climate change aims? The answer is very simple: no it’s not.

‘The big problem with net zero is there’s all kinds of definitions of it. And when you’re talking about the future of humanity and the future of life on Earth, you have to be definite in what you’re talking about….. Net zero can actually mean pretty well anything. The common definition that is out there in the science centers like MIT is, countries will get their emissions down as far as possible and then they will remove the CO2 in the atmosphere that’s left over.

It’s absolutely crazy. It contradicts all the climate science that we’ve had for the past twenty, twenty-five years, which is very definite. Emissions have to be dropped. In 1990, it was 80 percent, like, in a matter of years. And now, of course, because we’ve got better science, as I say, the IPCC made a very important, headline statement, right? It was one of the single most important statements of the big fifth assessment: near zero. Not net zero. Near zero for CO2, for methane and for —

Paul Jay
Where did this net zero terminology come from?

Peter Carter
Well, it came from the scientists. There’s been some net zero papers, a few of them, published a fairly long time ago. But after the big failure of the Copenhagen conference in 2009, and I don’t know whether it was coincidence, but the big disappointment came immediately after that conference. You know, the big disappointment. We all got very depressed about it because everybody knew in 2009 we’re in a catastrophic climate situation. Everybody knew that. The media were great. The media were telling us. And then, of course, you know, nothing happened.

But what did happen is that the science and the policy makers started publishing material that made solutions seem a lot easier. But a lot easier is not how you ensure our survival. So, they started talking about net zero. They changed the two degrees C limit from an equilibrium limit forever to a limit only by 2100. And of course, warming doesn’t stop. Climate disruption doesn’t stop at 2100. It continues for hundreds and hundreds of years.

So, “net zero” got into the policymaker lexicon. And also, they introduced as the key mode of calculating mitigation this thing called “cumulative carbon.” That had been published long ago, but they made it, again, very indefinite. We’ve got an indefinite cumulative carbon target. We’ve got an indefinite whatever-zero-emissions-means. My first website that I did long ago was on CO2 and explaining to people that CO2 lasts practically forever, as David Archer of Chicago, one of the world’s leading modelers on CO2 and climate, has said. It lasts forever. It doesn’t just last for hundreds and hundreds of years. CO2 — our emissions in the atmosphere — lasts for many thousands of years. Therefore, it follows logically and by computer models that you have to stop emitting. You have to stop emitting CO2 because it is so persistent and long-lasting in the atmosphere. That makes it so cumulative: it builds up, builds up, builds up, builds up.

We now have a concentration of CO2 in the atmosphere that is the highest in 23 million years. I like to use this science because it’s such excellent science. These scientists can track carbon dioxide back this far: millions and millions and millions of years. I like to use that data because I think that’s something that would impress the public and impress policymakers. Isn’t this crazy?

Paul Jay
Let me just let me make sure I get clear on this. So, what they have in mind for net zero is that either through carbon capture or some new technology that will take carbon out of the atmosphere, you don’t have to phase out fossil fuels [as fast]. You can find other ways to get to zero.

Peter Carter
You got it, Paul. That’s the whole thing. It’s a deceptive, clever (in the worst sense of the word) way of not having to shut down the fossil fuel industry.’

It is very simple. For humanity to have a future (and it has to be said that the odds are at the moment that humanity does not, in fact, have a future), the entirety of the global fossil fuel industry has to end by 2050, 2060 at the absolute latest. Not ‘be mitigated’. Not to have emissions ‘be reduced’. But for the entirety of all energy production, in all contexts, all over planet Earth, to be replaced by renewables or nuclear by 2050, 2060.

And if you don’t believe me:

‘The IPCC report has it (i.e. CO2) being virtually phased out by 2050. This is not net zero. The best-case scenario, which is the only survivable scenario, is something like an 86 or 87 percent reduction of fossil fuel production [by 2050].’ (And reducing to more or less 100% by 2060).


Peter T 12.02.20 at 9:29 am

Picking up on steven t johnson’s question at 14 – “who is going to profit from these changes?”. It would be useful to distinguish at all times between “adds value” and “makes money”. The two are not synonymous, and they cannot be brought into alignment easily – probably not at all. A large part of the problem is that most of the changes needed to bring ourselves to sustainability will add value but cost money. Some will require government spending; others will prevent people from making money (eg stopping forest clearing or over-fishing or coal mining).

The value gain will be less visible to most than the monetary loss – and those with the most money will have the most to lose.


reason 12.02.20 at 10:20 am

Just a question you mention only wind and solar (and really the biggest easy gain for solar is to put solar panels on nearly every roof), wind will run out of locations. What about tidal and wave energy. They would seem to me to be an important complement.

And energy saving is an important part of the mix. Please no more every family driving around in a truck and living in drafty, poorly insulated housing.


reason 12.02.20 at 10:35 am

It seems to me though the biggest unknown is what will happen with bio energy. It may be possible to have special cultures produce highly concentrated fuels by photosynthesis (I have heard of a process under development that produces hydrogen). Of course that will compete with agriculture for land. But agriculture itself will need (anyway of course) a massive technological and product change. For lots of reasons we need less animal product, less grains and more vegetables. It may be possible all animal products will be replaced with substitutes of one sort or another (the guardian mentioned today that singapore had allowed cultured chicken meat for human consumption).

What worried me though, is that people keep dreaming of “green” energy as though it is necessarily environmentally safe. Thermodynamics however tell us that any use of energy produces heat. The heat itself can be a pollutant. We need to worry about that.


Plucky Underdog 12.02.20 at 1:05 pm

Technically, pretty good. But you introduce the initialism “DRI” in para 5 without explanation. Doubly jarring, because you introduced “PV” correctly, earlier on.


Plucky Underdog 12.02.20 at 1:12 pm

Omega Centauri wrote:

Primary energy, if I have it right, is the gross energy contained in fuels. To a thermodynamics or physics person, this is low quality energy, and much of it is lost in the conversion to high quality energy -mainly mechanical work or electricity. Most renewables directly generate “high quality energy”, mainly electricity, without the need for conversion

This point is absolutely key to the debate, yet somehow it always slips through the cracks. Granted, it makes the accounting somewhat more complex, but given how far it lowers the bar (a factor of 2-3!) it would be well worth giving it more space.


notGoodenough 12.02.20 at 3:54 pm

“Improvements in battery technology are crucial to the next major step in the process, electrifying transport.”

This is true. Certainly the Battery 2030+ roadmap makes this quite clear. Interestingly, AFAICT, the main advances to be made in EVs will be with respect to cost, energy density, and lifetime (though, to be clear, the overall Battery roadmap includes a lot regarding improved use, decreased reliance on “bad” elements, and pushing 2nd life and design-for-recycling) [1].

In light of this it is, perhaps, worth considering Jeff Dahn’s more recent work [2] which is very, very promising (the advances being made using good engineering and configuration, testing in commercially available cells using the typical NMC//Graphite setup, and shows performance of 15,000 cycles). To be clear, this isn’t pie-in-the-sky results – these are cells which are scalable and representative (for a more general overview, I’d recommend Jeff’s presentation [3]). It demonstrates that the Li-ion technology is, when well engineered, capable of offering very good lifetimes – and, the potential implications of decreased costs here are quite significant (particularly if combined with sensible reuse policies).

”However, the shift to electric vehicles can yield a substantial reduction in emissions only if electricity generation is already largely decarbonized.”

This is, of course, a key point – EVs in and of themselves are not “the” answer to GHG reduction, they are one key part of the puzzle. Still, work in this area is looking very rosy – though it is important to keep improving and to broaden our technological options [4].

[2] DOI: 10.1149/2.0981913jes
[4] Insert my usual note regarding basket of storage/basket of production – a diverse energy portfolio is important. Given that I’ve said this about 5 million times by now, I hope I don’t need to once again go into vast detail on this point…


notGoodenough 12.02.20 at 7:29 pm

“Commitments to decarbonization have not, as yet, been matched by concrete policy measures. But the goal of zero net emissions by 2050 is entirely feasible and would, if achieved, stave off most of the worst consequences of climate change.”

True-ish, with a notable “but”. I’d recommend, to those interested and with time to do so, having a look through the figure from both global and more regional perspectives – this added granularity might prove useful for consideration.

[While I originally planned to write something much longer on this, trying to meet the pre-Christmas workload means it is still tricky to find time. So, I will try and give my “in a nutshell” perspective, and see what people make of it – bear in mind that much of this will be outside my expertise, so certainly some caution is warrented.]

However, before I offer my quick thoughts, I will insert the disclaimer that I am not saying everything is sunshine and rainbows, nor am I discounting the immense issues facing us. So, whenever I say anything positive please mentally follow it with “but clearly improved climate change action is critical, and complacency is completely unjustified as even best case scenarios will have severe negative consequences” [1]. Thanking the commentariat in advance.

To focus, for a moment, on the EU+UK – even before the pandemic the results from 2018 showed a 23% decrease of GHGs wrt. 1990 levels [2], which is higher than the 20% by 2020 targetted by the Paris accord. Given that 40% is already targeted by 2030, with recent proponents of the EU green deal (such as Ursula von der Leyen) pushing for 55% by 2030, this represents a big step towards improving the EU’s positioning wrt. climate change…

…“but clearly improved climate change action is critical, and complacency is completely unjustified as even best case scenarios will have severe negative consequences”. [Everyone remembered, right? Good. Thank you.]

All this has been achieved without notable damage to the economies (for those who care about such matters), with clean R&D actually proving beneficial by generating “knowledge spillover”. Of course, some sectors have actually grown their emissions, even though the net was a negative (for example, international aviation has proven to be unhelpful from this perspective).

Interestingly, many of the EU’s “1.5 degree” projections don’t consider much contribution from carbon removal technologies even by 2050 [3]. As these technologies are in infancy, and many rely on CRMs, this is probably sensible. Indeed, most of the reductions seem to be planned to come from power, industry, and transportation. Clearly, then, this is a wee bit more than mere propaganda meaning “let’s do next to nothing for the next 20/30 years and then panic when we realise we have done nothing”.

However, as shown recently, the big emitters are reluctant to strengthen Paris agreements to better meet the 1.5 C target. And so, while there is positive news that the CAT’s projection of “current policies” has fallen from 3.6 C (2015) to 2.9 C (now), it is notable that improving the NDCs (nationally determined contributions) is vital.

Indeed, overall global emissions are rising, with much of this emanating from China (note: this isn’t to say “China is bad” or to assert “western superiority” – this is just noting the situation). From the data, it seems a major driving factor is coal-based electricity – this is, therefore, a pretty obvious area for emissions reduction. However, currently (after a briefly promising plateu) China seems – if anything – dangerously close to going in the opposite direction.

But, to offer a purely personal opinion, I don’t see any reason that this must necessarily remain so. Unless there is an ideological component (those with more experience of Chinese society could perhaps consider this point), China is generally fairly good at rapidly instituting vast-scale changes within its country (for good or ill). Given that it is, as it happens, one of the world’s leading producers of renewable energy generation equipment and of batteries, large scale transfer to renewables (and, to the extent necessary, nuclear) would seem to be the lesser problem. Instead, the greater problem appears to be managing the economic and political implications of fossil-fuel phase-out. AFAICT, coal consumption dropped in to 2013 – 2015 period, when subsidies ran out (and the industry was then propped up by subsidies, suggesting that – as in the US – the coal industry is propped up mostly by the government rather than any economic competitiveness). Given this, it is perhaps worth contemplating how dependent China is on coal-power vs. how dependent it need be. Is it really so likely that China will ignore the developments in this area happening in its own backyard, as well as the ability to take the lead technologically and on the international stage with respect to geopolitical power? Well, perhaps – but to assume this must necessarily be the case would seem to me to be a somewhat odd position, unless of course there is a good reason for why this must be the case which I’ve missed (always a possibility, of course!). Thoughts supported with evidence are, as always, appreciated.

To offer a hopefully interesting point, I recently came across a report [4] which may be of interest. This suggests that when considering the LULUCF question which has been raised, the first step is to stop deforestation. Surely that seems a fairly axiomatic response? Perhaps one relevant paragraph:

“Net zero GHG emissions by 2050 can be achieved by phasing out deforestation by 2030 and maintaining the rate of carbon storage projected for forests by 2030 until 2050. This would reduce total GHG emissions including LULUCF by 66% below 2005.

Factoring out the non-CO2 emissions from the land use change and forestry sector, this would have Australia’s net-CO2 emissions reach zero by about 2038, with net negative CO2 emissions prevailing thereafter (see Figure 12for land use scenarios). If the rate of carbon storage projected for forests by 2030 can be doubled by 2040 net-CO2 emissions would reach zero a few years earlier by about 2035, and net zero GHG emissions would be achieved about ten years earlier in 2040compared to 2050 in the case where the rate of carbon storage projected for forests is maintained at 2030 levels.”

Now, of course, such broad brushstrokes are outside my area of expertise, but it seems to me that it is sensible to look at what sectors can be reduced to zero, which cannot, and adjust required carbon capture accordingly. After all, AFAIK, zero-emmission agriculture is beyond our ability – so unless one plans some sort of offset here, the alternative is, to put it bluntly, to kill everyone. And, while that would admittedly have the potential to solve quite a few climate-related issues, I am not sure it will gain much traction. And, again, the more we reduce emissions in other sectors, the less we must consider “off-setting” and the more time is bought – which, to me at least, seems more promising than the alternative.

It is also worth remembering we have yet to see what social changes make result from the recent pandemic. Increased teleworking would help reduce emissions from transport and office buildings, with potential improved profits and little downside for those businesses to whom this applies. Of course, this doesn’t mean it will happen (never underestimate the irony of how bad capitalists are at capitalism), but it will be interesting to see potential knock-on factors.

To try to find a suitable stopping point for this rambling, I will note that while there are plenty of reasons to be frustrated and angry, it is worth remembering the considerable advances which have been made – characterising this as a “lack of progress” ignores that progress has been made, and gives license to those taking a “well, this is impossible so we might as well not bother” approach. For example, for long periods I have heard the argument “but there’s no point in reducing emissions if China doesn’t” (I see you there, Littlejohn). Clearly that is rather short-sighted, and most countries are not opposed to taking advantage of advantage of the knowledge learned by other countries)

And so, while I wouldn’t hold up the EU as a resounding success [remember my disclaimer!] it does provide an interesting blueprint. Consequently, as more and more countries show that decarbonisation is perfectly possible, the momentum will build – the EU’s targets for 2030 are tough-but-doable, and are a good foundation to reach net-zero by 2050.

Given this, and the technological (and, less rapidly, social) advances, by all means be sceptical and commit to holding those responsible accountable. But remember that progress has been made – and it is possible to learn from this, and it is by no means to late to commit to a more sustainable future [5].


[1] For example: “there are dramatic improvements to battery technologies…but clearly improved climate change action is critical, and complacency is completely unjustified as even best case scenarios will have severe negative consequences”.
and “renewable energy is gaining prominence…but clearly improved climate change action is critical, and complacency is completely unjustified as even best case scenarios will have severe negative consequences”.
and “I like Lady Grey tea…but clearly improved climate change action is critical, and complacency is completely unjustified as even best case scenarios will have severe negative consequences”.

[2] it is important to be careful, as pre-2005 there is limited data regarding precise emissions. However, I will use the EDGAR values as these are (to the best of my knowledge) fairly representative.

[3] COM(2019)559/F1


[5] not discussed for want of space and time: sustainable design of cities and urban landscape planning, the potential for improving equality and reforestation by meaningful action, the synergy between reduced GHGs and reliance on outmoded models such as those which have an inherent lack of sustainability, and a thought regarding the potential impact “new deal” style approaches may have (I think it could be greater than many believe, particularly if coupled with certain reforms). I will exercise some restraint here – much, I’m sure, to everyone’s great relief!


Matt 12.02.20 at 8:23 pm

The only thermodynamically favorable and scalable approach to carbon sequestration I see is accelerated silicate weathering (also called enhanced silicate weathering in the literature).

The reaction between carbon dioxide and alkaline earth silicates is thermodynamically spontaneous in the presence of water, but kinetically hindered. It’s a reaction with slow diffusion of reactants through the product layer, limited by surface area. Crushing rocks rich in alkaline earth silicates and distributing them in near-shore ocean environments produces an accelerated version of the geological carbon cycle. It still requires vast-in-absolute-terms amounts of energy to crush billions of tons of rock, but it’s not running uphill against thermodynamics.


Mg2SiO4 + 2CO2 → 2MgCO3 + SiO2: ΔH -89 kJ mol/CO2


Mg3Si2O5(OH)4 + 3 CO2 → 3MgCO3 + 2SiO2 + 2H2O: ΔH -64 kJ mol/CO2


CaSiO3 + CO2 → CaCO3 + SiO2: ΔH -90 kJ mol/CO2

For references, see section 7.2.2 “Chemistry of mineral carbonation” in the IPCC’s Special Report on Carbon dioxide Capture and Storage.


steven t johnson 12.02.20 at 10:10 pm

Carbon dioxide is a waste product of animal respiration, not a poison. It is only a poison in the same sense in which oxygen is a poison. This is noticeably true in the case of diving and submarines. Air with no carbon dioxide at all would be a health hazard, by the way, especially to sleepers, which would make carbon dioxide a very unusual poison.

Incorrectly using an emotive term like poison is rhetoric, in the bad sense of the word. Why does a case for zero emissions need such emotional manipulation?

The humor in the joke about sterilizing all topsoil to get rid of fungi is that decomposition of organic material is in the end equivalent to incomplete burning. This is why incorporating carbon dioxide into plastic is a form of carbon fixation and a step toward zero emissions. The toxic hazard from a plastic house fire, as opposed to a wooden house fire though….

Zero emissions by the way literally means phasing out natural gas too, as burning natural gas also produces carbon dioxide. Plus, although commonly ignored, methane, which is what natural gas largely is, is a more potent greenhouse gas than carbon dioxide, even more than water vapor if I remember correctly. Are there really good figures on the amount of methane emissions from leakage?


Hidari 12.03.20 at 7:45 am

Covid-19 gives us an opportunity (probably our last) to decide where we want to go as a species. Either we start to move towards a non-CO2 society/economy right now (not next year, not in ten years time, not in 30 years time) but right now, or else we miss this historic opportunity: forever.

Instead of dealing with mythical, science fictional, non-existent technologies that might (or might not) ‘suck’ the CO2 out of the air at some indeterminate point in the future (and it is the mass production of these (currently) mythical technologies that the ‘net zero’ idea is based one), we need to reduce our production of fossil fuels by 6%, starting next year, every year, essentially until fossil fuels are no longer burned for energy (which should happen no later than 2060). In other words, as I said, gross zero CO2 emissions (or near as, dammit) by 2060 not from individual countries by everywhere on Planet Earth.

This is why #keepitintheground is the only slogan that has meaning and the application of which might save us (slightly, to a certain extent).

The problem with the emphasis on renewables is twofold. First, as @22 points out, renewables produce CO2 as well (albeit at a much lesser rate) than fossil fuels). In an absolute sense there is literally no such thing as green energy and we all need to face up to that.

Second, it creates a myth of progress. What has happened up to now is that we gain more of our energy from renewables, yes, but we also get more of our energy from fossil fuels.

In other words, renewables get used as well as fossil fuels.

That’s not what we need.

What we need is for renewables to be used instead of fossil fuels. That’s what is (so far) not happening, which is why all the happy-clappy statistics about how cheap renewables are and how good the batteries are nowadays are irrelevant.,year%20between%202020%20and%202030.&text=Policymakers%20can%20support%20a%20managed,through%20six%20areas%20of%20action.


notGoodenough 12.03.20 at 12:21 pm

For those who care about actual data – happy clappy or otherwise:

Since 2005 the EU’s consumption of fossil fuels has decreased from 1,836 MTOE to 1,674.9 (2017). While various factors are responsible, of particular notice were energy efficiency improvements and an increase in the share of energy consumed from hydro, wind and solar photovoltaic (PV) power. Indeed, since 1990, the decrease in fossil fuel usage (natural gas (46.4%) oil and petroleum (35.3%) and solid fossil fuels (27.9%) has been matched with a corresponding increase in renewables (except for 2011) [1]. So both as a percentage, but also in real numbers, fossil fuel use in the EU has declined, as renewables have increased.

Of course, correlation does not equal causation, but it is a rather striking trend. It also seems, at least to me, that those suggesting that the introduction of renewables are not having an impact appear have yet to make a good case for that.

[brief aside to address one of the concerns with renewables mentioned in this thread regarding CO2 and heat (I’ve already discussed at great length other issues raised regarding renewable and green tech, so I won’t mention those again here). CO2 emissions related to renewables are primarily from industrial processes – as energy production is decarbonised, this will decrease. There are also contributions from material extraction – the majority of which being Si – but again, as the power behind this becomes less carbon-generating, this too will decrease substantially. Reason @ 22 mentions concerns regarding the thermal contribution from the inherent energy inefficiencies – and although this is an interesting point, I don’t see any reason why this should be more from renewables than from any other form of energy production. The biggest threats contributing to climate change are from GHGs, which would seem to be the more pressing concern. As renewables help deal with that, there seems to be little reason not to push renewables replacing fossil fuels as much and as fast as possible. It is also worth remembering that this will help push other “green tech”, and so we would also expect to see corresponding increases in thermal capture, storage, and use (these fields are often quite closely overlapped – so much so that my non-profit institute has both electrical and thermal energy divisions, despite our shoestring budget). Should overall energy use be flattened / decreased? Absolutely. But given the importance I see of wide-spread renewables, I am not convinced this is the biggest issue]

To wrap this up, as personally amusing as it has been to see entire fields of science and technology – and all those working in them – dismissed with a mere handwave, I have found it interesting how the arguments have gone from “batteries don’t work which is why renewables are dumb” to “well, actually renewables and storage are irrelevant” in a matter of weeks. Presumably we can shortly expect EVs to be added to the list of things which must be ignored as not relevant to climate change. I will admit that sometimes it almost seems as though people are starting from a point of objecting to renewable energy and are working backwards from there – but I like to think better of people, and will assume that that is in no way the case.

However, for those who don’t believe that technological innovations have done anything to mitigate climate change, I have a sincere request – please outline your proposal. Not just “don’t emit CO2” (which is the goal), but how you are going to get there in detail. What are the steps you would favour, how will these be implemented, what pushback do you anticipate, what changes do you want to see, and what deadlines do you have in mind. It doesn’t have to be every detail (that would be a lot to ask!), but just the broad brushstrokes.

As I’ve said many, many, many times, I believe we are going to need improvements from both technology and society. I find it odd that some seem very determined that the former play no role – but that being the case, I am certainly open to whatever alternative plan they may have.



Omega Centauri 12.03.20 at 4:49 pm

This article gives an inkling of the multi-decade effort needed for really scaling up solutions. In this case European offshore wind.
This sort of effort needs to be replicated elsewhere, and for other technologies as well. Sustained commitment is more important than a crash program. Just the sort of continuity the US political system doesn’t deliver.


Kiwanda 12.04.20 at 1:41 am


The problem with the emphasis on renewables is twofold. First, as @22 points out, renewables produce CO2 as well (albeit at a much lesser rate) than fossil fuels). In an absolute sense there is literally no such thing as green energy and we all need to face up to that.

Second, it creates a myth of progress. What has happened up to now is that we gain more of our energy from renewables, yes, but we also get more of our energy from fossil fuels.

The first point is so wrong-headed that it’s hard to guess what solution, other than mass death, would be considered sufficient.

The second point is, I think, that the amount of fossil-fuel consumption may not go down even if renewable energy production goes up, if total consumption of energy goes up.

Again: oil is used mainly for transport, and transport is going battery-electric, via direct consumer appeal and government fiat and/or encouragement. As that happens, oil consumption will go down.

Again: renewables are now the cheapest new sources of electricity, even ignoring climate and health, and in many places it is now, or soon will be, cheaper to build new renewables than to run existing fossil-fuel plants. Since even people who don’t care about climate or health still like money, renewable production will take over from fossil-fuel production, and fossil-fuel consumption will go down.

That leaves, among other things, using fossil fuels for heating houses, offices, factories, and industrial uses of heat. The long term cost of ground-exchange heat pumps is, I’m pretty sure, lower than using fossil fuels, but the up-front cost is higher. So adopting heat pumps would be greatly increased by government intervention, probably at least including loans. (Although there are companies that willing to make the investment themselves.)

None of this is “happy clappy”, or “we’ll get back to this in a few decades”, it’s happening right now, based on current economics, and again, even ignoring health and climate considerations.


KT2 12.04.20 at 3:57 am

Solutions ranked.

notGoodenough @30. Great request…
“… I have a sincere request – please outline your proposal. Not just “don’t emit CO2” (which is the goal), but how you are going to get there in detail. What are the steps you would favour, how will these be implemented, what pushback do you anticipate, what changes do you want to see, and what deadlines do you have in mind. It doesn’t have to be every detail (that would be a lot to ask!), but just the broad brushstrokes.”

Trying to decide if we will go extinct or sign cooperative agreements – in time with enough support – has led me to this “Table of Solutions”. We ALL may be surprised where our favourite ‘remove ghg’s solution’ hobby horse [knowledge + biases + first world zeitgeist] sits against other solutions.
(Doesn’t JQ do all this for us? (-:)

See “Table of Solutions” with co2 amounts at link.

* Gigatons CO2 Equivalent Reduced / Sequestered (2020–2050)

*Reduced Food Waste
Food, Agriculture, and Land Use / Land Sinks
Health and EducationHealth and Education
Plant-Rich DietsFood, Agriculture, and Land Use / Land Sinks
Refrigerant ManagementIndustry / Buildings
Tropical Forest RestorationLand Sinks
Onshore Wind TurbinesElectricity
Alternative RefrigerantsIndustry / Buildings
Utility-Scale Solar PhotovoltaicsElectricity
Improved Clean CookstovesBuildings
12.Distributed Solar PhotovoltaicsElectricity
SilvopastureLand Sinks

“Project Drawdown uses different scenarios to assess what determined, global efforts to address climate change might look like. Both scenarios shown here are plausible and economically realistic. Drawdown Scenario 1 is roughly in-line with 2ËšC temperature rise by 2100, while Drawdown Scenario 2 is roughly in-line with 1.5ËšC temperature rise at century’s end.

“The results shown here are based on projected emissions impact globally. The relative importance of a given solution can differ significantly depending on context and particular ecological, economic, political, or social conditions. We invite a deeper dive into the many particularities and nuances of all of these solutions.”

And I’d like to see against this list, a ‘feasibility of uptake’ metric as well. Such would assist in immediate support or strengthening activities. And, linked to politicians voting records, who to vote out.


Area Man 12.04.20 at 8:54 pm


Thermodynamics however tell us that any use of energy produces heat. The heat itself can be a pollutant. We need to worry about that.

Huh? Thermodynamics tells us that solar and wind energy do not actually produce any net heat (whereas the burning of fossil fuels actually does). And at any rate, all of the waste heat produced by human activity is totally insignificant compared to that big burning yellow spot in the sky.


Hidari 12.05.20 at 7:50 am

I’m going to bow out here, as there are lots of people who have persuaded themselves, apparently, that all the increasingly apocalyptic news about the environment is, in fact, good news, and that ‘market forces’ are going to save (presumably, the implication is, like they have saved us in the past, which is why life is currently so utopian in the advanced capitalist countries at the moment).

To which my response is simply what one anonymous CT poster posted a few weeks back, balefully:

Markets got us into this mess. Ergo, markets are not going to get us out of this mess.

Despite all the happy-clappy (hopey changey, as someone once put it) rhetoric:

There are only two numbers of significance here: literally, only two. They are not the price of renewables, or the percentage of power that is produced by renewables, or how much Europe has cut emissions etc. etc. etc. although there is a gigantic propaganda operation to make you think that.

The only two numbers that have any meaning are these:

1: The global average atmospheric carbon dioxide, in ppm


2: The global surface temperature (GST). (actually one could simplify matters and say that in reality this is the only number that really matters).

And in both cases, of these figures, there are only three questions that are of significance. Literally. No other questions are relevant.

Are these numbers going up?
Are they stable?
Or are they going down?

If the answer to the first question is ‘yes’ then the answer to the question ‘are we anything meaningful to solving the problem of global warming’ is obviously not ‘yes’ is it?

The Earth is burning. CO2 is causing this. Every year, we all continue to make the problem worse facilitated by the wonders of the fossil-fuelled capitalist system.

Those going on about renewables have things precisely backwards. It’s not that we need to develop renewables, as such (although we do). It’s first, and most importantly, we need to cut emissions of CO2 ( gross not net). Then, we hope that renewables ‘take up the slack’. They might, or might not. That’s not really the problem. The problem is the CO2 in the atmosphere. We need to stop making this problem worse (solving this problem is currently beyond our technology).

Now it’s absolutely true that we will need carbon reduction technologies in the future to reduce the damage we have already done.

But that’s tomorrow’s problem.

You are all misconceptualising this problem. You are talking as if this is a problem like: ‘where are my car keys?’ In this case, you have a problem (lost car keys), you have a set of possible solutions (kitchen, bedroom, bathroom etc.) and you work through these logically, and then, when the problem is solved, you forget about it and go on with the rest of your day.

Global warming is not a problem like this.

Global warming is a problem like: here is a person who has been in a fire and has 3rd degree burns all over her body. How do we use technology (plastic surgery etc.) such that the harm caused by this is reduced and this person can function in society? Here there really is no solution to the problem. The woman will have the physical and psychological scars for the rest of her life. But one can reduce the amount of harm.

Or another way of thinking about it.

A house is on fire. The firemen (us) stand outside the fire with firehoses. But instead of water, they are pouring petrol (gasoline) onto the fire. When someone points out the insanity of this someone points out, ‘well I think you will find that the rate at which one of the firemen is pouring petrol onto this fire has reduced 22%! Besides we are developing technology that will, in 20 years time, ‘suck’ the petrol out of the house. So the problem is practically solved!’

The problem is not the rate of change of the amount of petrol you are pouring onto the fire. The problem is the fact that you are pouring petrol onto the fire (and even when you stop doing that, the house will still be on fire).

So: to repeat: emissions must reduce: to zero (gross). This will not solve the problem, at all (we will need technology that we currently do not have to solve it). But it will stop making it worse.

Any solution which is not predicated on the idea that we must reduce CO2 emissions, in a relatively short period of time (30/40 years) to zero, gross, is, quite simply, not a solution. At all.


notGoodenough 12.05.20 at 3:02 pm

KT2 @ 33

Thank you for the interesting link. From a superficial reading, I think this is in keeping with my general sense of the situation – climate change will need to be addressed along multiple fronts (some social, some political, some technological, etc.).

Regardless, it looks like there’s a lot to go through and think about, so I will do so before drawing any firm conclusions.


Omega Centauri 12.05.20 at 3:42 pm

Area Man
You missed the point. The point was we don’t need to replace 100 BTUs of “primary energy”, with 100 BTUs of renewables, since only about 35 BTUs of that primary energy was useful to do work, but virtually all of the renewable production is. So the scale of the problem isn’t as bad as it at first appears.


steven t johnson 12.05.20 at 4:23 pm

Area Man@34 is incorrect on one point. All conversions of energy from one form to another increases entropy, that is, releases un-usable heat into the environment. There are no exceptions. In the case of wind, converting the kinetic energy of the moving air increases heat by friction in the wind mill. In the case of solar photovoltaics, the conversion of light energy into electricity also raises the temperature of the cell, plus of course the heat loss by the electric current produced. (Why computers have to be cooled, right?)

The notion that the KE of wind or the energy of the photons in light comes from the sun and the total is thereby set and conversion losses don’t matter superficially makes sense. But distribution of the energy is what ultimately matters for the effects on climate. The issue reminds me of people who decide the KE of a crashing asteroid would remain the same even if Bruce Willis blows it into pieces and therefore the whole idea of blowing up asteroids is stupid. What is stupid would be someone declaring it would make no difference if a hundred pound rock or a hundred pounds of ping pong balls were dropped on them. The same issues apply to the total energy from the sun.

Thus, it makes a difference if photovoltaics absorb light rather than reflecting it the way natural materials tend to do, in different degrees. (PV cells are generally black for a reason.) It makes a difference if local temperatures are higher, for all manner of things like evaporation of water, the amount of heat radiated into space (especially at night,) the number of organisms in the locale, how effectively winds equilibrate heat energy from the sun over the globe. If the capture of UV energy by ozone in the stratosphere can make a difference, and it does, so does leaving heat energy in winds over our heads and so does draping all our roofs in reflective materials rather than black.

One issue, the magnitude of human interventions? If on a cold morning the car in front of your house has less (or no, or softer) frost on the windows facing the house, then it should be obvious there are a multitude of effects, subtle or gross. Measuring the magnitude of effects in a process where in a sense there are no separable variables to label independent and dependent is tricky.

Least important, but perhaps most amusing, Larry Niven imagine his puppeteer civilization moving their homeworld away from their sun because heat pollution had become such a problem.

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