Can we get to 350 ppm? Yes we can

by John Q on July 22, 2017

There’s been a fair bit of buzz about an article in New York Magazine with an apocalyptic picture of climate change over the next century. I’ll for a more complete response later. But as it happens, I was already preparing a much more optimistic view, arguing that, at least in the absence of political disasters such as a long-running Trump presidency, the world is likely to achieve stabilization of greenhouse gas concentrations around 450 parts per million by 2050, and reduce that to 350 ppm by 2100.

On current models, stabilization at 450ppm gives us a 67 per cent chance of holding the long term increase in global temperatures below 2 degrees. Warming of 2 degrees would not be cataclysmic for humanity as a whole but it would be a disaster for many people and also for vulnerable ecosystems such as coral reefs. That’s why wants to reduce concentrations to 350 ppm from current levels above 400 ppm. Is that even possible? In my view, the answer is Yes.

I’ll start with the 2050 target. From the Australian Climate Change Authority, of which I was a Member until recently, here’s a set of emissions trajectories consistent with a 67 per cent probability of limiting warming to 2 degrees.

There’s a pretty good case to be made that we are on the blue trajectory, and that, with decent political outcomes, we will be able to go below it and hold warming to the Paris aspirational target of 1.5 degrees. That would still have plenty of negative effects, for example on coral reefs, but it would not be an existential threat to humanity.

The points that are critical in the blue trajectory are a peak in emissions, right about now and a drop to zero net emissions by 2050. The first looks to have been achieved. As for the second, we are already seeing commitments to this goal from developed countries and jurisdictions, and there’s every reason to think it can be achieved at low cost.

Instead, we’ve had a series of favorable technological surprises of which the most striking have been the plummeting cost of solar photovoltaics, and advances in battery technology allowing both low-cost electricity storage and affordable electric vehicles. There’s no reason to think these advances have run out, or that any of the remaining problem areas (air transport, cement manufacture and so on) will prove insuperable.

What these developments mean is that carbon-based electricity generation is on the way out, and that the end of the internal combustion engine is in sight, probably well before 2050.

Should this have been a surprise? It has been for me. As an economist, I’d have thought an outcome like this would have required a global commitment to an emissions trading scheme with a carbon price on a rising trajectory to $US100/tonne or so. In fact, we’ve seen nothing of the kind. There has been no real global co-ordination, and where carbon prices have been imposed, they have been low and limited in scope.

But maybe I shouldn’t have been surprised. There were a lot of potential technological options out there, and we only needed a couple to work. There were plenty of failures and disappointments (nuclear fission and fusion, carbon capture and storage, biofuels, geothermal) and more limited successes (energy efficiency, solar thermal and wind power) along with the surprise success of PV. The same point may be made in the particular case of storage. Any reversible process involving energy can form the basis of a storage technology, so there is a huge range of possibilities, from flywheels to pumped hydro to batteries based on many different chemical reactions. Viewed that way, it would be a surprise if we couldn’t find a good one.

On the other hand, there’s no obvious technical reason why we couldn’t have developed most of these technologies decades ago. So, it clearly needed a push from policy and public concern to get them to happen. Solar feed-in tariffs of 50c/kwh may look excessive now, but policies like this, in Australia and elsewhere, gave the industry the start it needed. Even without price incentives, the importance of the problem attracted attention from researchers and technologists that might otherwise have been allocated elsewhere.

So, I think, we can reduce emissions from fossil fuels to zero by 2050, and keep concentrations below 450 ppm at that point. What are the options to reduce concentrations over the following fifty years? In the absence of some new technological fix (not implausible, but there’s nothing in sight as of 2017), there are three main possibilities

* Reducing methane emissions and concentrations. Methane emissions arise mainly from agriculture (paddy rice and ruminants), with some possible addition from fracking. It appears feasible, though not trivial, to greatly reduce these sources at fairly low cost. And because methane has a short residence time, a reduction in emissions will lead fairly rapidly to a reduction in concentrations. The conversions are very tricky, but the radiative forcing associated with methane is currently about 0.5 watts, compared to 1.94 for CO2. So, if methane concentrations were reduced by 40 per cent, that would be equivalent to a 10 per cent reduction in CO2, or about 40 ppm.

* Natural absorption. Only around 50 per cent of the CO2 we emit (the so-called atmospheric fraction) ends up as increase in atmospheric concentrations, with the rest being absorbed by oceans. After that initial addition to sink, CO2 stays in the atmosphere for a long time. However, there is still some additional absorption by sinks. Yale Climate Connections suggests that around 50 per cent is absorbed in 50 years, and around 70 per cent in 100 years. So, by 2100, an additional 20 per cent or so of the CO2 emitted around now will have been absorbed by sinks. A rough estimate would be 0.2*(450-280) or 35 ppm, where 450 is the peak concentration and 280 the stable pre-industrial level. Of course,this is far from an ideal solution, since CO2 contributes to acidification of oceans and therefore to coral reef decline.

* Reforestation and other land use changes. Land use change is currently a big net contributor to global warming, but a systematic program of reforestation could turn this around. The potential has been estimated at 85 ppm.

Against these possibilities, there is currently a net cooling effect, equivalent to around 50 ppm, from aerosols associated with air pollution. Hopefully, pollution will be reduced over the coming century, but that makes the task of stabilizing the climate a bit more difficult.

A question I haven’t yet been able to find a good answer on is: how much warming would a trajectory peaking at 450 ppm and declining to 350 ppm ultimately produce? If anyone can point me to a good source, that would be great.

Finally, at least some of the pollutants we’ve emitted over the past century will, on our current understanding, stay there for hundreds or thousands of years, leading to long term problems of sea level rise. But if we can get to 2100 without destroying the planet through climate change or nuclear warfare, I’m sure our great-grandchildren will work out some way of cleaning up what’s left of our mess.



Billikin 07.22.17 at 10:40 am

“the surprise success of PV”

What’s PV?



Bob Zannelli 07.22.17 at 11:47 am

I don’t share John’s optimism, but I hope he’s right. I do think we have the technology to accomplish what John thinks we will accomplish, we aren’t in an impossible situation. But at least based on current trends while solar and wind are expanding , the use of fossil based energy production is increasing even faster. More troubling we are seeing increased use of coal. In Germany and Japan, the move away from nuclear power has caused these countries to , not use more renewable energy , but more greenhouse gas emitting power sources.

Advocates of solar and wind ( and I count myself among these people) continue to make exaggerated claims about the growing use of these renewable sources. As an example, were one to read some articles by the advocated of solar and wind, you might think that the Netherlands gets most of its energy from wind. In fact it currently gets 4% from wind energy and this has been accomplished at some significant cost.

My point is not to argue against wind and solar, we need to expand the use of these power sources , even if it means somewhat higher costs. ( and I expect their cost to continue to fall, especially solar. ) I agree with John that the continuing improvement in battery technology holds out great hope to shift transportation to electric and away from I.C.Es

But there are some things we should not do. We should stop shutting down nuclear plants due to public fear and cheap natural gas. We know doing this generally increases greenhouse gas emission. And we should not take nuclear power off the table. Advances in nuclear power technology has the potential to result in far safer designs and the production of much less waste. In addition, these new designs hold the promise of being competitive with energy production from natural gas. Nuclear advocates have
indeed made exaggerated claims , and there have been terrible accidents, but this doesn’t mean that these new designs hold no promise. Today’s modern car is not the model T.

In the United States the utilization of the large stockpile of “spent” nuclear fuel is sufficient to meet all the energy needs of the United States for two hundred years at the current energy use rate. and adding depleted Uranium expands this to twenty two hundred years. I am not suggesting we go to 100 % nuclear , I just use these number to illustrate the potential. Anyone wanting more information on this can email me, I would be glad to make this information available. ( I have given talks on this topic)


Hidari 07.22.17 at 1:08 pm

Point 1: ‘China is by far the world’s largest carbon emitter, accounting for 29% of the world’s annual output.’

Point 2: ‘Why has Chinese emissions growth slowed?

The simple fact is that growth in coal consumption has stopped. In fact, coal consumption declined at around 1% per year on average since 2013. This is in stark contrast to the rapid growth of around 10% per year in the 2000s….

Why has coal consumption declined?

One important point is that growth in total primary energy consumption has slowed. This is really driven by a weakening economy. GDP growth rates are much lower now than they were in the 2000s. Less economic activity, means less energy consumption…

The “war on coal” sounds impressive, but this may just be a smart rhetorical deflection from continuing economic woes. The coal is still there, it is just that coal power plants are running less of the time.

A recent study estimated that a decline in construction activity explained about three-quarters of the decline in coal use. This is since construction requires energy-intensive inputs of products such as cement and steel.

(therefore) Economic woes are behind the recent slowdown in Chinese coal consumption and emissions.

Are current emission trends inconsistent with China’s emission pledges?

It is … unlikely that Chinese emissions have absolutely peaked, in the sense that they will soon decline. Cancelling the development of new fossil fuel infrastructure does not reduce emissions.

To be consistent with a 2C target, Chinese emissions would have to go down as fast as they went up, and that is unlikely without retiring existing fossil fuel infrastructure.

If China was building 2-3 coal plants per week in its peak growth phase, then it needs to decommission 2-3 coal plants a week (and replace with other energy sources) in its peak decline phase to keep within a 2C target.

China’s emissions may be near a plateau, but unlikely that we will see emissions trend downwards to be consistent with a 2C target.

Should we trust Chinese data?

(short answer, sort of, kind of, but not really)’

Tl; dr

Global warming (i.e. the pumping of carbon dioxide into the atmosphere) is increasingly a coal problem, and, therefore, increasingly a Chinese problem.

The current ‘stabilisation’ in global emissions, assuming it’s real, is mainly because of the slowdown in the Chinese economy.

To repeat: it may not be real.

It is possible that Chinese (and therefore world) CO2 emissions have peaked. It is equally plausible that Chinese (and therefore world) CO2 emissions have not peaked. We just don’t know.

All the rest is smoke and mirrors. What we do know is that the ‘peak’ of CO2 really has to be in the next 5-10 years (ten years from now absolute maximum) and that emissions really have to come down rapidly from then on, or else we are in terra incognito, possibly literally.

Please not I am not contradicting the OP. I am merely saying that at the moment we simply do not know for sure that its premise (that global CO2 emissions have peaked) is true.


Stephen T Johnson 07.22.17 at 1:32 pm

PV=Photo voltaic, solar cells which generate electricity directly, as opposed to solar thermal, which is used to run turbines or whatnot. PV is the happening side of solar power, as efficiency climbs and costs plummet.

Power storage is problematic because of scale – it’s pretty doable at the individual and small institutional levels, pretty problematic at the national grid level. It’s certainly needed for wind & solar, our two best renewables so far.

Personally, I suspect fission isn’t going anywhere soon. Fusion really just needs (relatively) affordable superconductors that work above 100K and can be formed into the magnetic coils with (reasonable) ease to become a mostly engineering problem.

My two cents worth, I may be wildly mistaken


Eskimo 07.22.17 at 1:54 pm

PV = photovoltaic?


soullite 07.22.17 at 2:05 pm

All of which could have been avoided had the Democrats actually opposed ‘free trade’, instead of just pretending to for twenty years.


David Weigel 07.22.17 at 2:19 pm

“What’s PV?”

Photo-voltaic, I’m guessing.


CDT 07.22.17 at 2:56 pm

PV=photovoltaic solar panels, now the dominant solar technology. CSP=concentrating solar power, a declining competing technology for utility scale projects (in part because of water use).


Sam Penrose 07.22.17 at 3:05 pm

1) Yes we can. Read
2) We have to actually prevent the burning of fossil fuels, cutting down of forests, etc. It doesn’t matter how successfully we provide renewable energy unless we actually sequester more carbon than we emit.
3) Point 2 requires politics. See battle over cap and trade in California (AB398), Justin Gerdes’ Quitting Carbon for how progress is possible but difficult in, er, progressive places. Now extend to Russia, Saudia Arabia, Venezuela, Nigeria …

Your post would be better if it addressed point 3. Especially the unfortunate challenges of pricing: as natural gas replaces coal in rich societies, it becomes cheaper. As solar PV becomes common in an area, it requires complements and market restructuring to avoid having negative value (the “duck curve”).


Peter Dorman 07.22.17 at 4:40 pm

I would like to share John’s optimism, and once upon a time I did, but now I don’t. We could go into the details, but the main point is that the modeling community, the folks who generate the emissions scenarios you find in the IPCC reports, aren’t optimistic at all. I haven’t checked in about a year (and intend to do so soon), but at last inspection the most favorable scenarios still had the world overshooting up to the mid 500’s (ppm) and then utilizing a currently nonexistent carbon-sucking technology to bring us back down to 450 by century’s end. And the modelers themselves have talked about this; the tone of their discussion is, to put it mildly, very worried.

If my reading of this literature is wrong, I’d appreciate pointers to corrective sources. As you can imagine, I’d really, really like to be wrong.

As a second point, I’d encourage John and others who engage in the scenario-juggling game to bring the probabilistic aspect of the problem to the foreground. John briefly mentions a 2/3 probability of 2 degrees in one scenario, then moves on. The entire science and politics of climate change is about probabilities and how much risk we are willing to take. An example is the reference in the OP to a potential 85 ppm mitigation potential from reforestation. Yes, we should definitely do what we can to bulk up our carbon sinks, and reforestation is mostly a good thing (when it doesn’t conflict with other ecological goals or human rights imperatives). But there is significant uncertainty about (a) how forest and other sinks will respond to unavoidable future climate change, and (b) how future people, facing pressing adaptation challenges, will manage those sinks. (If agriculture suffers, people may expand cropland at the expense of forests, for instance.) By all means pursue the options that are out there, but potential carbon mitigation from something like reforestation is not money in the bank, so to speak. (And it is a serious mistake to allow people to trade mitigation that is certain, like reduced fossil fuel use, for mitigation that is chancy, like forestation offsets.)


Joseph Brenner 07.22.17 at 5:13 pm

I’m with Bob Zannelli@2 on this one, and in fact I’m afraid that this John Quiggin piece is going to become my main exemplar of what annoys me the most about renewables enthusiasts. “Hey everybody, the problem is solved! We don’t need to worry!” What could possibly go wrong with that message?

The last I looked into these issues was a few years ago, so I can’t really argue in detail– one of the joys of internet-era renewables enthusiasts is they act like any information from two years ago must be horribly out of date– but every time I’ve looked into it, I’ve concluded largely what Bob Zannelli concludes: every single positive development you hear about in wind and solar is at best overplayed and exaggerated, and at worst evaporates completely when you look at it closely (e.g. see the much heralded German Energy Transition which hasn’t actually done anything to restrain their CO2 emissions).

The one point where I part company Bob Zannelli@2 is on his reference to nuclear power’s “terrible accidents”. We’ve had accidents, and we’ve had terror about them, but calling them “terrible accidents” sounds very serious and conventional but is arguably wrong. Phrases like that should be reserved for incidents that actually kill lots of people.

John Quiggin:

Instead, we’ve had a series of favorable technological surprises of which the most striking have been the plummeting cost of solar photovoltaics,

I’ve seen the graph of dropping photovaltaics costs, but it’s just one component of a solar power system.

and advances in battery technology

Have there been advances in battery technology? I just keep seeing grand product announcements from Saint Musk.

allowing both low-cost electricity storage

Are we talking about something that’s actually been done, or just something you think can be done?

There’s no reason to think these advances have run out,

By the same token, there’s no reason to assume they haven’t.
We’re talking about betting the planet here.

or that any of the remaining problem areas (air transport, cement manufacture and so on) will prove insuperable.

I’d be interested in what we’re going to do for cement, myself.

There were plenty of failures and disappointments (nuclear fission

Once again, calling nuclear power a failure and disappointment sounds very serious and conventional, but doesn’t really hold up. Twenty percent of US electrical power– actual power, not gosh wow some day soon power– is clean thanks to nuclear power. It could be more than that if the US had gone the way France did back in the 70s.

and fusion,

There are some fusion power startups out there that would object to calling it a failure (the article of faith in that world is that it’s the giant, expensive torroidal designs that have been the failure, and this is a case where the market needs to rescue government-funded research).

carbon capture and storage,

The last IPCC report thought CSS was an important direction to go. You know better now?


Matt 07.22.17 at 6:54 pm

I’m significantly more optimistic about the technologies for reducing fossil use than I was 5 years ago, in particular photovoltaics and electricity storage. I’m even less optimistic about the politics than I was 5 years ago. In Germany, Poland, Australia, China, Czechia, South Africa, the United States, and probably more, environmental progress has repeatedly been sacrificed on the altar of “coal jobs.” Not even that traditional excuse “economic competitiveness” — governments are expending resources to prop up economically marginal coal mines and plants, to ensure that cleaner, cheaper electricity doesn’t kill them off. The US hasn’t (yet) reached the “direct state subsidies” stage like Poland, but the new administration may yet get there. And signs are ominous that they’re employing every indirect weapon possible to hobble the cleaner competition.

Electric vehicles aren’t yet mature enough to pose any sort of threat to oil consumption. Maybe in another decade, if we’re lucky. I fear that even when/if the technology gets there we’ll see obstructionist roadblocks in the name of “oil and gas jobs” the same way coal is fighting renewable electricity now.

Finally, it will be “interesting” (to say the least) if EVs really take over, oil prices collapse, and most OPEC members experience corresponding economic/social stresses like Venezuela has endured over the last few years.


Billikin 07.22.17 at 7:37 pm

“PV=Photo voltaic, solar cells which generate electricity directly”

Thanks, everyone.


Billikin 07.22.17 at 7:54 pm

Wouldn’t carbon mitigation from reforestation be money in the bank if it prevents future costs?


Heliopause 07.22.17 at 8:08 pm

“a much more optimistic view…a 67 per cent chance of holding the long term increase in global temperatures below 2 degrees…with decent political outcomes.”

So if I’m reading this correctly, the optimistic view is that if politicians outside the globalist consensus never win an election ever again, hence the globalist consensus retaining control (against rapidly rising anti-globalist sentiment), and they adhere to their aspirational targets, it’s only one out of three that we all die regardless and two out of three that only a couple billion Bangladeshis and Indonesians will have their worlds destroyed.

You wanna run the pessimistic scenario by me?


Omega Centauri 07.22.17 at 9:02 pm

CDT: CSP=concentrating solar power, a declining competing technology for utility scale projects (in part because of water use).

I am of the strong opinion that CSP is going to become increasingly important as the integration
costs of PV rise steeply after roughly 40% penetration is reached. CSP with thermal storage is
likely to be a lot more affordable, that PC plus batteries. As an example from Wikipedia about
Solar Reserve which seems to be the leading developer:

Crescent Dunes Solar Energy Project
The 110 MW Crescent Dunes Solar Energy Project is the world’s first
utility-scale facility to use molten salt power tower energy storage. It has
10,347 tracking mirrors (heliostats) that follow the sun and reflect and
concentrate sunlight onto a heat exchanger, a receiver, atop a 640-foot (200 m)
tower. Crescent Dunes has 10 hours of storage and will deliver 500,000 MW hours
of electricity per year, day and night, to 75,000 homes. In September, 2011,
SolarReserve received a $737 million loan guarantee from the U.S. Department
of Energy (DOE) for the project and broke ground. The project has a 25-year
agreement with NV Energy for 100 percent of the electricity. Construction is
complete and the project went online in the fall of 2015. Under the rollout
plan with NV Energy, the facility will ramp-up over the coming year.

Redstone Solar Thermal Power Project[edit]
The Redstone Solar Thermal Power Project is 100 MW solar project located at
Postmasburg, near Kimberly, South Africa. The project will have 12 hours of
storage to deliver to more than 200,000 South African homes. The project is
planned to be online in 2018.

Copiapó Solar Project
The Copiapó Solar Project near Copiapó, Atacama Region, Chile is a 260 MW
hybrid solar power project consisting of CSP and PV energy. It will have 14
hours of storage to deliver to more than 560,000 homes in Atacama. The project
is the first of its kind in Chile and will be the largest solar power plant in
the world. At the 2017 auction, SolarReserve bid $63/MWh (¢6.3/kWh) for 24-hour
CSP power with no subsidies, competing with other types such as LNG gas

Now admittedly the Atacama has by far the worlds best insolation,
being both exceptionally dry, and at high altitude. But, that’s a pretty low
bid price for baseline solar power -especially for a first of its kind


Nick the Quick 07.22.17 at 9:09 pm

Given current political trends though, we’re probably facing roughly 50% chance of a situation where warming gets up to like 4 degrees & things get super gnarly for a maybe a half century or so, but then it will stabilize & in 150 years we’ll have like 3.5 billion people living really well with air conditioning & good internet, medicine, education, freedom, etc.


bruce wilder 07.22.17 at 9:13 pm

I appreciate Peter Dorman’s comment, particularly his caution on risk. It bears pointing out that 2/3 probability of 2 degrees is masking a roughly 1/3 probability of completely losing control of climate, as human additions to the carbon cycle give way to secondary forcings as the primary drivers of continual rises in temperature and other disruptive effects, and human adding or removing carbon from the carbon cycle loses its traction against climate.

The loss of traction that may occur progressively as the period of high carbon levels lengthens from decades to a century is not a matter solely of overshoot. The Arctic Ocean is not going to refreeze, sea level isn’t going to return to previous levels in prompt response to stabilizing the carbon cycle at some higher level.


Dots 07.22.17 at 11:51 pm

Can’t speak for non-US folks but here in the US the anti-warming party is also anti-fiscal deficit, anti-finance, anti-war, and pro single-payer, which is to say we r the stingy party that will put the brakes on most any equilibrium-jumping economic catalyst available in postindustrial USA, even as we lose every election at every level

I hope the electric car works out. I see cheaper flights to more places, sprawling SWern suburbs, growing average home and car sizes, recent tech and method improvements in coal and oil extraction, massive GDP growth in desperately poor countries, and a scary potential for Trumpism to sell millennials on imprudence like Reagan did Boomers


Omega Centauri 07.23.17 at 2:14 am

I’m glad Bruce mentions that we will be fighting against slow climate feedbacks, we won’t be dealing with a simple system that just trends back towards its unaltered state, once the human driver is removed. There is a lot of carbon currently frozen in permafrost, what will its fate be? There are slow albedo feedbacks, caused by changes in vegetative cover, and changes in landice cover, that span a substantial range of timescales, and these mostly will act to amplify the changes due to greenhouse gases.


bad Jim 07.23.17 at 6:26 am

I’m not optimistic that we’re going to find a way to sequester enough carbon to reduce atmospheric CO2. Reforestation and green roofs help stabilize the carbon balance, but by themselves they don’t reverse the trend. Gregory Benford suggested floating agricultural waste from the midwest down the Mississippi and letting it sink into the Gulf; perhaps not the greatest plan, but the idea of growing things and then burying them points in the right direction, since we got into this problem by burning things which were buried millions of years ago.

The electric car is here. I drive a Chevy Bolt. 240 miles costs me about $8. Straight line acceleration is awesome, and I show off at every opportunity. (My town is lousy with Teslas, but do they show off? Hardly ever. They’re luxury cars: look at me.)

California is adding solar power so rapidly that the grid and the power companies are struggling to cope. Baseload power becomes problematic when there’s less demand for it at noon than at midnight. The shift to renewables is happening so quickly that studies from three years ago are irrelevant.

The utilities want to replace their plants as they age, in no small part because they can build the cost into their rates, but demand is declining due to increasing efficiency and solar supply, so the grid (the state) is starting to push back, saying “We don’t need your generators.”


Gareth Wilson 07.23.17 at 7:43 am

If you really want to reduce carbon emissions, remove the right to sue for any injuries from ionising radiation. You can set up a public Radiation Compensation Corporation to pay actual damages if they can be scientifically proven.


Hidari 07.23.17 at 7:59 am

It’s also worthwhile pointing out that we have a large amount of data about energy transitions. The data tells us that it takes, roughly, about 50 to 60 years from the data when the new energy source first becomes viable to when it reaches the ‘top spot’ (which is not 100% or anything like it, but more than 50% of global energy production). In other words, based on past experience, renewables will account for 50% or more of global energy production roughly by the year 2080. Please note that that 50% of global energy production in terms of ‘raw numbers’ will be a much larger number than that at present, as global energy demand continues to rise. Or, to put it another way, the 50% of energy production which isnot renewable will be a much larger ‘raw’ number than the equivalent now (remember, 1.2 billion people currently don’t currently have constant access to electricity: presumably they are all wanting this to change).

Of course, this might be wrong, and the transition could be sped up, but only if politics ‘steps in’.

Politics is not stepping in. Trump’s election in the US was a disaster for the environment, but the May victory (May currently being in power with the support of the extreme-right DUP) was an equally telling reminder that our political structures are failing in terms of the challenges of the 21st century. The May govt. is of course aggressively hostile to the concept of continued human life on planet Earth, and the DUP even more so (i.e. they tend towards ‘climate change denial’). ‘Everyone’ has pointed out the new wave of authoritarian leaders in nominally democratic states (Netanyahu, Erdogan, Duterte etc.): far fewer people have pointed out that they are all, to a man (sic) hostile to environmental policies. And yet, as the song has it, ‘the future belongs to them’.

So, ceteris paribus, in the absence of some currently unheralded technological breakthrough, the likelihood is that the transition to renewables will take place over much the same timescale as our previous transitions.

It’s also noticeable that this thread on CT has attracted much less attention than others, even though its topic is, so to speak, ‘objectively’ of far greater importance than any other CT topic . But the ‘liberal’ intelligentsia has spent a lot of time and energy denying the implications of climate change (almost as much time and energy as the right wing commentariat has spent denying the reality of climate change).


John Quiggin 07.23.17 at 8:51 am

@23 I’m no fan of May or of the Cameron government that preceded her, but their period in office has seen the virtual disappearance of both coal mining and coal-fired electricity generation in Britain.

I agree tabout, and mention in the OP, the threat of Trumpism.


Proteos 07.23.17 at 1:33 pm

Getting to 350ppm by 2100 might be technically feasible, but the possibility that it occurs in reality seems to be so remote that the synthesis report of IPCC’s AR5 states that «Only a limited number of individual model studies have explored levels below 430 ppm CO2-eq» (Table 3.1).

RCP2.6, which is basically the “likely less than 2°C” average scenario, sees a radiative forcing in 2100 roughly equal to 2050’s, which means that the CO2 concentration is more or less constant from 2050 to 2100. Going to 350ppm would require a huge human induced drawdown of CO2: while I’m not a specialist of the domain, the scientific consensus does not appear to see natural drawdowns as large as you seem to imply.

It’s true that RCP2.6 does not even foresees the fossil fuels emissions going to zero in 2050, not to speak about total emissions, but I see this as a testament of how optimistic are the curves in the original post. It has to be said that RCP2.6 requires things that do not exist yet such as BECCS to scale very rapidly, and can therefore be considered extremely optimistic.

Finally for the renewable energy optimism that we’ve already been there. In the 60s-70s, some people were saying that nuclear power would take over the world in no time. Suffice to say it has not turned out this way. It’s great that solar PV has seen a huge relative growth recently, but one should not forget it still barely registers in terms of share of global energy production.


bruce wilder 07.23.17 at 6:18 pm


2050 is as far from us in political time as Reagan and Carter and Thatcher. There is room ahead for many reversals of fortune and shocks to the system.

Politics is about agreeing to disagree while still taking action. This is where the politics of climate change has been breaking down: the demand that everyone accede to a common view and the tribal accusations of denial. Socio-economic class figures heavily in the divide. Pissing off the creative class which wants its mastery of the jargon of science and love of electric cars to translate into status is part of the dynamic; it is an attitude not unlike that expressed by Henry’s photo of Trump’s America. (Both the attitude of the one wearing the t-shirt and weight, and the attitude of the fotog.)

People are going to have a great range of ambivalence about the implications of climate change in particular and the increased and unsustainable weight of human activity in general. We are not going to settle on optimism alone, and optimism will not necessarily lead to effective collective action rather than complacent negligence. That is the problem of ambivalence in general: that it is a centrifugal force and creates no attachment to actual policy without provoking equal and opposite reactions sparking off in random directions. Some people like apocalypse, as a story at least; whether such stories motivate thought and considered response or despair and passivity is, I suppose, a function of charismatic leadership among other things. Others are repelled by the fashion for panic, as they see it, but whether that leads to acceptance of a need for measured and prudent response or resignation to having to cope with what must come, is difficult to plan.

I actually think we need, collectively, a huge effort at educating ourselves to the economic implications, both with regard to how small the change and how massive (both being true)

It is hard to wrap one’s head around something on the scale of climate change. Different people, even well-informed as few of us truly are, will still have different opinions, attitudes and temperamental inclinations as well as interest. But, a high level of understanding is necessary to accepting the legitimacy of collective action.

It would certainly be convenient if peak oil combines with the advance of computing and communication tech to make pv cheaper than oil; simple efficiency is always a good excuse. But it will not be politically acceptable, if the economic argument that pollution generates good jobs continues unchallenged among the formerly working classes.
Anymore than if the bizarre self-deception that driving a Prius will do anything appreciable to save the planet continues to prevail as conventional wisdom among the modern jet setting bourgeoisie.


Hidari 07.24.17 at 6:29 am


Ironic you mention Thatcher and Reagan, as it is of course due to the CO2 their governments pumped into the atmosphere that we are currently undergoing the temperatures we are currently enduring. Remember there is a ’40 year time lag’: so .6 degrees of global warming is already ‘locked into’ the system: even if The Rapture occurred and all human beings were wafted up to Heaven, the global temperature would keep on rising for 40 years. I have noticed a huge and prolonged effort by the ‘intelligent’sia to avoid talking about or thinking about this.

I’ve clicked on some of the links in the OP and they are interesting but terribly, terribly speculative. In the name of the band: ‘We Were Promised Jetpacks’. I am old enough to remember ‘Futurologists’ not just predict but promise moon bases, colonies on Mars, AI, manned interplanetary exploration, flying cars, all sorts of goodies, by 2017. (The aphorism, ‘We were promised 140000 MPH, we got 140 characters’ also sums up how disappointing and tedious the ‘future’ has turned out to be).

All these environmentally friendly technological innovations sound lovely. But if there is anything that the history of the last 50 years teaches us it is that technological innovation is slow, unsteady, complicated, expensive, and does not operate via a strict, deterministic timetable (the ubiquity of the iPhone/tablet is sui generis: it was not replacing an existing technology). Even assuming that they work, and are cheap (speculative) there’s no guarantee that they will replace existing technology within the required timescale.


MFB 07.24.17 at 7:15 am

Obviously, specific countries such as Britain can get rid of coal mining for power generation and iron production. This is not, however, a big global improvement if (as is the case) the reason is a) moving over to natural gas (which is a carbon-emitting fossil fuel however much you hype it) and b) moving over to imported coal for iron production and a massive decline in iron and steel production, plus c) importing your finished goods from elsewhere without asking how much fossil fuel is used for the finished goods.

We are now at a stage of global warming at which a massive global increase in temperature is inevitable; reducing to zero emissions will take several decades if we start now. Increasing the amount of power generated by renewables by twenty or thirty times — a minimum if we are to preserve any kind of conventional lifestyle — will take several decades and will cost an enormous amount of money. (What is often forgotten is that renewables are costly to maintain; those spinning turbines need to be replaced because they wear out, solar cells last only twenty years, and so on.) Nobody is politically prepared to spend that money, and for the most part politicians are using rhetoric instead. (Please notice that Obama promised a green economy and then, once elected, attempted to turn the United States into a net fossil fuel exporter. In practice he is not superior to Trump.)

It would appear, therefore, that 500 ppm is quite possible and that nobody now alive will see a return below 400 ppm. Somebody said that this would be “gnarly” for a few decades. With all due respect, this word refers to the death of several billion people and the very strong likelihood of a full-scale global thermonuclear war over depleted resources, which would leave the planet unable to support land-based life above the level of arthropods.

It amazes me that the Western petit-bourgeoisie take things like global warming so frivolously. (And, incidentally, blaming it all on China is equally frivolous. Who do you think is buying all that crap that China is burning that coal to produce? Have you forgotten your beloved globalisation?)


Dick Veldkamp 07.24.17 at 12:38 pm

I see another problem with John Quiggin’s “optimistic” scenario (see also 15 Heliopause) which is the underlying assumption that the whole economic system will basically keep on operating as today. If the system collapses for some reason, it is goodbye to all those nice technical solutions.

Don’t get me wrong, nothing I would like more than to be proven wrong on this.


Omri 07.24.17 at 5:20 pm

Sorry, but I have to throw a little cold water on your claims:

The fossil fuels we are burning are made of carbon that was sequestered before the emergence of fungi on the earth’s surface.

Capturing carbon through photosynthesis and then sequestering it stably is no longer something we can expect the earth to just do for us. If it’s feasible at all, you’ll see the Dutch doing it in no time: Grow poplar in a polder. Harvest the timber. [apply Nobel-prize winning technology here] Bury it in the polder. Carbon gets captured. Polder is elevated. Everyone wins.

Otherwise, assume the worst.


Matt 07.24.17 at 5:50 pm

What is often forgotten is that renewables are costly to maintain; those spinning turbines need to be replaced because they wear out, solar cells last only twenty years, and so on.

Utility scale PV systems require quite a bit less operation and maintenance expenses than coal. Last year NREL estimated it at $15/kW/year for fixed-tilt systems or $18/kW/year for single-axis tracking systems. In 2014 Power Technology magazine estimated the corresponding O&M figure as $43/kW/year for subcritical coal generation, the type of coal that dominates in the US. Raise that to $88/kW/year for slightly cleaner supercritical/ultra-supercritical coal plants (those that Australian coal promoters are rebranding as “high efficiency low emissions,” apparently meaning that “not quite as high as the very highest” now qualifies as “low”.)

Solar plants require far fewer permanent workers than coal after they are constructed. Even amortizing their construction labor over the plant lifetime, and accounting for the fact that they’re expected to need equipment replacement faster than coal plants, they are all-in-all significantly less demanding of labor per megawatt-hour produced than old king coal.

If solar boosters talk jobs it’s usually to emphasize that solar produces a lot of jobs. But the high job count is an artifact of rapid change. It’s as if the various US states were pondering a switch to driving on the left hand side of the road instead of the right hand side. California switches sides first. Analysts from the Lefthandian Motor Lobby compare California to other states and excitedly proclaim that left-hand driving produces 10x the jobs of right-hand. But they’re lumping all the temporary transition jobs in with the steady long term jobs. If they think that driving on the other side will make road-work a new employment-for-life, we-always-need-more-good-people kind of sector, they’re going to be disappointed.

To the extent that fossil lobbyists talk about solar power and jobs, it’s just to take the breathless solar employment claims at face value and invert the sentiments. “Heartland Institute study shows that left-hand driving is 10x less efficient than right-hand, using the Lefthandians’ own numbers! Another explanation why the UK is poorer than right-thinking, right-side USA.”


James Wimberley 07.25.17 at 7:39 am

Hidari: China’s reported GDP growth was 6.7% in 2016, same so far this year. A slight drop from the old days, but still rapid by any other standards. The coal drop is matched in pig iron. It’s all about tertiarisation and not at all recession.

It is not a given that primary energy demand will rise much. Jacobson’s US model give a roughly 50% drop from electrification (cars go from 20% efficient to 80%, generating plants from 40% coal/60% gas to 100% by accounting definition). This is not SFIK controversial, and can be read off the LLNL Sankey charts. The same pattern must hold for other OECD countries. In poor ones like India, there will still be net growth in energy demand. But coal generating plants in India are already struggling financially. Adani, Tata and Essar have each offered controlling stakes in gigawatt generating plants to the Gujarat state government for 1 rupee each.


Hidari 07.25.17 at 8:19 am

If anyone cares this article here:

sums up how I feel about it, but it also has a lot of links at the end to other articles (I.e. about the NY piece) which take a different view, some of them much closer to the opinion of the OP.


sanbikinoraion 07.25.17 at 12:36 pm

On the other hand, Matt, if we are talking about a 50-year process of solar/wind installation projects to scale renewables up to the required production volume, then, well, 50 years of installation work is a lifetime career for a generation starting now.


Hidari 07.25.17 at 8:49 pm


Assuming that China’s statistics are accurate.

But are they?

‘China burns half the world’s coal. And China also struggles to accurately measure and report its emissions.
How inaccurate are China’s numbers?
The New York Times recently reported that China’s “pollution and energy data can be unreliable or outright fake.”
Widespread accounting problems have become a major issue threatening the roll out of China’s new national carbon market. In other words, they don’t trust their energy accounting enough to rely on it themselves….

China is certainly not the only nation with inaccurate coal numbers. India and others struggle with this too. Partly it is caused by developing nations’ lack of resources. Partly it is caused by the growing pressure to under-report the numbers….

As the impacts of climate change and air pollution continue to grow worse, pressure is growing on foot-dragging governments and industries to fudge their numbers so they appear to be acting more vigorously than they really are.
This is true around the world, not just in China. For example, the metastasizing Volkswagen emissions cheating scandal revealed a widespread, intentional effort to under-report emissions on a global scale. And that cheating occurred in a highly-regulated industry with required verification tests.
Caixin reports on another recent example from China: “Recent Environmental Ministry inspections found that one-third of manufacturers in northern China had tampered with emissions data to avoid heavy penalties.” There is now a “cottage industry” to help fake the numbers. That cheating also took place in a regulated industry that required verification tests….

The New York Times reported on verification in China: “Like some other nations, China, the world’s biggest polluter, has refused to accept international monitoring of its emissions and says it will provide data to outside observers. In the past, conflicting data about the country’s energy use has raised questions about accuracy…Furthermore, there are persistent differences between coal consumption statistics reported on the provincial and national levels.”
Widespread emissions cheating is occurring even in highly regulated areas with mandatory verification testing. It is even more tempting to under-report coal burning numbers because they are mostly self-reported and there is no way for others to disprove the claims.’

To repeat: the recent ‘pause’* in emissions is a good thing if it continues and if it is actually happening.

*This is a deliberate allusion to the ‘pause’ in rising temperatures much lauded by the political Right in the noughties which turned out to be not really much of a pause at all.

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