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Why we Need CCS - Part 5: Bridge to a Sustainable Energy Future


  • CCS together with bio-energy form an essential bridge towards a long-term sustainable energy future. This bridging strategy becomes abundantly clear in all IPCC mitigation scenarios. 
  • Considering the great growth ambitions of the developing world together with the recommendations of climate science, neglecting these bridge technologies can lead to disastrous longer-term consequences. 
  • The pursuit of more ideologically attractive clean energy options (renewables and nuclear) as a primary climate change mitigation mechanism is no longer an option and will arguably do more harm than good in the long run. 


Many developed world citizens participating in the energy and climate debate still appear to hold the belief that wind/solar or nuclear energy represent the best solution for the 21st century sustainability crisis and should be made the primary global energy priority ASAP. On the other hand, CCS and bio-energy are much less popular options that are often dismissed without putting much thought into the matter. Under more careful analysis, however, these less ideologically attractive clean energy options quickly emerge as the most logical solution to the global conundrum of massive developing world growth ambitions within a very tight CO2 budget.

It is fully understandable that people who have lived their entire lives in fossil-fueled developed world luxury would strongly advocate wind/solar or nuclear-dominated decarbonization pathways. Fossil fuels have already given us an enormous assortment of productivity-enhancing technology and infrastructure which allow us to use a very small portion of our disposable income on basics like energy. From this highly privileged viewpoint, it becomes very easy to entertain visions of not-so-distant futures dominated by distributed wind/solar power zipping along perfectly coordinated super-smart grids or an essentially unlimited supply of clean and dispatchable nuclear energy taking human civilization to the next level.

Unfortunately, however, the objective reality is that, barring a number of incredible technological breakthroughs, these visions are badly incompatible with the recommendations of climate science. This fifth and final part of the CCS series will take a closer look at the reasoning behind this statement and further build the case for a technology-neutral approach which would naturally favour the bridge technologies of CCS and bio.

The developing world

As described in a previous article on the matter, the developing world may well emit triple the amount of CO2 of the developed world a mere two decades from now (see below). It is also worth noting that this emission pathway is calculated assuming highly optimistic reductions in CO2 intensity (CO2 per unit GDP) of about 3% per year. In the previous decade, the world managed reductions of a mere 0.4% per year.

Exxon CO2 projection

The challenge becomes very clear when one considers that the 6 billion (and counting) developing world citizens essentially want a similar period of industrialization and increases in material consumption as the developed world enjoyed in the previous century. There are some key differences though: 1) the scale of the expansion will be at least one order of magnitude greater, 2) cheap conventional fossil fuels (especially oil) is approaching supply constraints and 3) climate change is now a very important factor. When considering that the world is already in a stage of severe ecological overshoot (see below), this presents a grave problem.


There are numerous reasons for encouraging the development of the developing world, chief of which is the elimination of the typical cycle of poverty where people born into large and poor families do not get access to proper education and end up producing large uneducated families of their own. For example, the projected quadrupling of the African population over the course of the 21st century (below) may well be an ecological and humanitarian disaster in the making, especially considering the potentially severe impacts of climate change on African biocapacity.

Projected population growth by region

Economic development is the best solution for curbing developing world population growth (see this article for example). Industrialization, urbanization and the resulting rapidly increasing demand for more educated workers has been proven to rapidly reduce fertility rates to levels below replenishment (e.g. Europe and Japan). We therefore have little choice other than encouraging a rapid and ecologically damaging expansion in developing world economic activity. In theory, we could do this slower and cleaner (although this would probably be politically impossible), but this will likely come back to haunt us in the form of further population pressure on an already full planet.

The role of coal in developing world growth

As shown below, nations almost exclusively begin the process of industrialization with coal. There are some very obvious reasons for this: coal is cheap, reliable, simple, versatile and often locally available in abundance. These properties make coal several times more rapidly scalable than any other alternative in regions of the world where economic development is prioritized much higher than environmental protection (almost all developing nations). Those who do not understand these priorities are encouraged to visit a typical developing world slum or spend a month or so trying to live on 10 times less disposable income.

Dominant fuel transition

Yes, we have many alternatives to coal, but they are nowhere near coal when it comes to fueling rapid industrialization. Capital costs of nuclear energy in China are about triple that of coal, implying that coal capacity can be expanded at roughly triple the pace of nuclear. Coal also has a multitude of direct industrial applications (almost half of Chinese coal is used directly in industry), adding another factor of two into the potential scaling rate. When also considering the value of the simplicity of coal in developing nations with large uneducated workforces, coal becomes roughly an order of magnitude more rapidly scalable than nuclear.

As an example, even though nuclear has expanded very impressively in China and India in recent years, the pace of expansion is still about 50 times smaller than coal in absolute terms. As an illustration of this fact, the coal and nuclear energy consumption rates in China and India are plotted below (based on BP data) where it is clear to see that the ratio of coal/nuclear consumption has remained consistently high over the past decade of rapid industrialization.

China India Coal Nuclear comparison

Wind/solar, in turn, are again several times less scalable than nuclear. Yes, in developed nations, nuclear is very expensive, takes many years to license and construct and faces great societal resistance, thereby making it less attractive than wind/solar at present. For the developing world (where the vast majority of new energy infrastructure is being constructed), however, the situation is very different. Nuclear capacity is only about twice as expensive as wind/solar capacity, implying that, when adjusted for capacity factor, it is at least two times cheaper. And then, of course, it must be mentioned that nuclear, unlike wind/solar, is a dispatchable technology that can be seamlessly integrated into tried and tested centralized electricity networks that will remain mandatory to power the rapidly growing megacities of the developing world for many decades into the future.

This brief analysis should make it clear that nuclear or wind/solar is not going to power 7% economic growth rates in the developing world. Unless we see some enormous shale gas expansion, this rapid growth demanded by billions of developing world citizens will continue to come primarily from coal.

Emissions lock-in and overshoot

The developing world will still require several decades of rapid economic growth before approaching the point where further increases in material consumption no longer translate into significant increases in happy life years (a point already reached by the rich world as shown below based on data from the Happy Planet Index).

Happy life years vs GDP per capita

As discussed above and in a previous article, this rapid economic expansion will continue to be driven by fossil fuels, primarily coal, thus resulting in continuously increasing CO2 emissions into the foreseeable future. Due to this simple trend, the world will have locked in all allowable emissions for the “fairly safe” 450 ppm target within the next 3 years and will probably overshoot this target sometime in the 2030’s. This implicitly implies that that, if climate science is correct, we will need to achieve rather impressive retroactive mitigation from existing infrastructure as well as some enormous negative CO2 emissions over the course of the 21st century. This will be the role of the bridge technologies: CCS and bio.

Building bridges

To illustrate the importance of bridge technologies, the IPCC has mapped out multiple decarbonization pathways on a very interesting tri-axis graph (shown below). It is abundantly clear that each and every scenario achieving CO2 concentrations in the range of 430-530 ppm first proceeds from unabated fossil energy to CCS and bio before making the turn up to the ideologically attractive future of nuclear and renewables. If climate science is correct, this really is the only viable path forward.

Decarbonization pathways

Considering the wide scatter that usually typifies the IPCC scenarios (something which is understandable considering the great uncertainties involved in forecasting global CO2 emissions almost one century ahead), the unanimous trend in the figure above really should send a very strong message. All mitigation scenarios resulting in CO2 concentrations deemed to be “reasonably safe” by the current scientific consensus on climate change first head to the right (CCS and bio) before turning upwards (nuclear and renewables).


Considering the enormous growth ambitions of the developing world and the very tight emissions budget prescribed by climate science there can be very little doubt that CCS and bio-energy must play a central role in the global energy future during the 21st century. Directly pursuing the ideologically attractive end-goal of a zero-carbon nuclear and renewable energy system is not a feasible strategy to keep global emissions within reasonably safe limits and a CCS+bio bridge towards this end-goal is clearly prescribed in all IPCC mitigation scenarios.

This is a vitally important point for all renewable/nuclear advocates to understand. Yes, the long-term future must be dominated by sustainable energy sources such as gen IV nuclear and wind/solar power, but advocating nuclear or wind/solar as a primary strategy for rapid CO2 mitigation can do more harm than good in the long run. In particular, ongoing technology-forcing of wind/solar power at the expense of much more efficient technology-neutral approaches will only serve to lock in additional unabated fossil fuel infrastructure and have almost no direct impact on global emissions due to the price-driven rebound effect. If climate science is correct, such a scenario can be nothing short of disastrous in the longer term.

Advocates should therefore be very careful when marketing renewables and nuclear energy as primary climate change mitigation mechanisms. Pushing for preferential treatment of these sources is at least just as detrimental to the longer-term sustainability of our planet as it is beneficial. Yes, there are good arguments for wind/solar and nuclear power, clean air and energy security probably being the two most important ones, but when it comes to climate change mitigation, these approaches fall far short of the less ideologically attractive alternatives of CCS and bio.

Finally, it is vitally important for developed world citizens to realize that these side benefits of solar/wind and nuclear are still of low importance in developing nations where disposable incomes remain around one order of magnitude smaller than in the developed world. In other words, the practicality, reliability and scalability of coal is still valued much higher than the air pollution it causes. Even climate change is a matter of less concern in the developing world since getting rich as quickly as possible is probably the best defence that these billions of people have against an increasingly hostile climate system. As an example, China is now starting to trade increased CO2 emissions for decreased air pollution through very large scale synthetic natural gas

It is fairly safe to say that nothing will stop the 6 billion (and counting) developing world citizens from pursuing rapid economic growth and, currently, there are no alternatives that even come close to challenging fossil fuels as the primary energy source behind this rapid industrialization. The choice is therefore simple: finally get pragmatic about climate change (scrap all technology-forcing policies for a true technology-neutral approach) or pray that climate science is grossly in error (on the pessimistic side).

Schalk Cloete's picture

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Schalk Cloete's picture
Schalk Cloete on Jul 26, 2014 4:41 pm GMT

Mike, three points about the wind vs. nuclear buildout in China:

1. Capacity factors. Chinese capacity factors are much lower than those achieved in the US – about 26% without curtailment and about 23% with curtailment. A good breakdown is given in this TEC article. Sure, capacity factors will improve over time as towers get taller and rotor diameters get increasingly oversized, but this will be a slow process. Using data from the BP Statistical Review, it can be calculated that the global average wind capacity factor has increase marginally from 21.4% in 2000 to 23.7% in 2013. You can verify this yourself using the BP data. The US is way above the average, mainly due to the excellent wind resources in the central states, but China is pretty average. 40% is therefore not a realistic number to use for generation projections. 

2. Subsidies. With enough support, deployment can evade economic realities for many years, but this usually does not end well. The great German Solar PV expansion followed by a 50% drop last year and a 40% drop so far this year is a good example. The typical boom-bust of US wind in response to the PTC is another. As stated before, China currently pays $83-100/MWh in tariffs for intermittent wind which also requires large additional investment in high voltage transmission lines – double that received by dispatchable thermal and hydro generation. Obviously, this trend is not sustainable in an economy that relies so heavily on cheap energy. As outlined in the previous TEC article I linked, cracks are already starting to appear in the support structure. 

3. Nuclear scale rate. According to data provided by the World Nuclear Association, China has completed 3.2 GW of nuclear in the past year (June through June) and begun construction on 5.7 GW. In total, China now has 33 GW of nuclear under construction. Nuclear construction in China takes 4-6 years, implying that we can expect an average of 5-6 GW per year for the next couple of years – an order of magnitude slower than the coal buildout achieved in the mid 2000s when the Chinese economy was still half the size it is today, but still quite impressive. Using real-world Chinese wind capacity factors, this puts nuclear generation on a similar path to wind. 

Only time will tell how long it takes for the fundamental advantages in terms of cost, dispatchability and grid connection of nuclear over wind to be reflected in the data. Naturally, the long construction times of nuclear energy has caused a delayed response to the great Chinese war on pollution declared a few years back while the modular nature of wind allowed for more rapid scaling. However, as illustrated by the bulging Chinese nuclear construction pipeline, this trend is set to change soon.

About the CCS scale rate, anyone who has studied the IEA and IPCC rapid decarbonization scenarios will know that the real CCS buildout only starts in the next decade (if the world manages to commit to the 2 deg C target in some shape or form). CCS does not have the ideological appeal necessary to win large subsidies and will have to wait until the world gets serious about climate change. Please see the second and third figures in the previous article in this series where I put the scale of the required CCS rollout in perspective using wind energy. The result really is quite striking. 

Joris van Dorp's picture
Joris van Dorp on Jul 28, 2014 12:33 pm GMT


I’d add that CCS is more than just a pipe-dream. It serves a very important public relations purpose. This is the concept of marketing new coal power plants by calling them “CCS-ready”. By stating that a new coal power plant is “CCS ready” it allows the politicians and plant owners to sooth the public into accepting such plants. After all: if the plant is “CCS-ready” doesn’t that mean that it will soon be a zero-co2 energy source?

Greg Rau's picture
Greg Rau on Jul 28, 2014 7:03 pm GMT

N Nadir,

You ask:

“Can anyone who claims that we “need” CSS show any place on this earth where a dump for 1 billion of these 31 billion tons is on the drawing board?”

Yes I can – the ocean. By spontaneously converting flue gas CO2 to dissolved Ca(HCO3)2 the ocean can store >100,000BT of CO2 in this form.  Furthermore, the addition of this alkalinity is beneficial to the ocean because it counters ocean acidification.

So carbon storage is not our problem, thinking that point source CO2 mitigation must result in making and storing conc CO2 – that is our problem.

“Where the plants to make the carbon capture reagents, be they amines or some other technology, are being built?”  

“It would appear that we barely understand the toxicology of the oxidation products of CSS amines, and the thermodynamics of the case is at best dubious, since if we don’t ban dangerous fossil fuels outright, we will need to burn more of them to capture their waste.”

“A recent paper in Environ. Sci. Tech. – the current issue in fact – sketches out some part of the former problem Environ. Sci. Technol., 2014, 48 (14), pp 8203–8211“Comparative in Vitro Toxicity of Nitrosamines and Nitramines Associated with Amine-based Carbon Capture and Storage.”)”

We don’t need exotic, toxic reagents or exotic conditions to make Ca(HCO3)2 from flue gas, all you need is lots of limestone and seawater at ambient T and P. Sure this will only be relevant at coastal sites and maybe 1 BT/yr of CO2 mitigation, but we will continue to have 0 BT/yr mitigated as long as CCS is view as the only game in town. And there are other ideas for consuming CO2, formation of mineral carbonates from mineral silicate for example. Anyway, agree that sufficient CO2 mitigation of power plants will never happen as long a CCS is the only tech offered. And yes I do think that we are screwed if existing power plants are not mitigated, there is no way that renewables and/or nuclear can dominate our energy supply fast enough to avoid another 1-2,000 BT of CO2 going into the air forever.  Game over unless we can reduce the C footprint of fossil energy while we transition to non-fossil energy.

Mike Barnard's picture
Mike Barnard on Jul 30, 2014 3:38 pm GMT

More substantive outlets than my blog requested variants of my debunking of Mr. Cloete’s interesting opinions on nuclear and CCS vs renewables.



Mr. Cloete is becoming moderately well-known. Perhaps he’ll find out if all press is good press.

Schalk Cloete's picture
Schalk Cloete on Aug 1, 2014 8:42 pm GMT

Thanks for spreading the word. I must say, I was pleasantly surprised by the critical nature of the discussion that developed below the Cleantechnica article. Given the clear technology preferences of Cleantechnica, this is very encouraging. Seems like the “myth” is quite some distance from being put to bed. Some more mythbusting awaits here

BTW, your reference to TEC as an “echo chamber” for nuclear over renewables is unfounded. If you look at the article profile on TEC, you will notice a good balance between technologies. In contrast, sites like Cleantechnica and Reneweconomy can be more accurately described as “echo chambers” because the vast majority of articles give positive press to a predetermined technology class, allowing advocates of these technologies to consistently reinforce each others’ beliefs without too much opposition. This is not possible within the technology-neutral environment on TEC. Thus, if you want some truly critical discussions of your ideas, I would strongly encourage publishing some material on TEC. 

Also, my article does not say that only nuclear can scale to prevent global warming and wind energy should be ignored. It simply states that both nuclear and wind scale much more slowly than fossil fuels (hence the need for retroactive CCS described earlier in the series), with wind/solar (in a technology-neutral environment) being even slower than nuclear based on simple LCOE and LACE considerations.

Schalk Cloete's picture
Schalk Cloete on Aug 7, 2014 10:07 pm GMT

I would highly recommend checking out this entire CCS series to get my full argument about why we need CCS. 

The full lifecycle emissions of CCS is about 20% of an unabated plant, so, even with the energy penalty, including CCS can achieve large emission reductions.

About storage, ocean storage will be the last option to be utilized. First will be EOR oil fields where CCS could even be profitable if scaled up, second will be depleted oil fields where infrastructure already exists to bring down costs and third will be saline aquifirs where huge volumes of CO2 can be permanently stored at very low risk of leakage. 

Mark Heinicke's picture
Mark Heinicke on Aug 12, 2014 3:19 am GMT


I’m a little surprised that as of this moment you have only one “like” (mine) for this post. Maybe it’s just not confrontational enough.  Your last sentence bears repetition among all parties.  

(altho you had 2 typos, sorry)

More technically, what kind of TES are you recommending?  It’s great in principle, and it’s being used in CSP but capacity is pretty low (not that capacity would have to be all that high in a solar facility, given the necessarily small scale).  I’m envisioning some humongous collection   of tanks.  ?  

I like better Engineer-Poet’s mention of the “gray” control rods used in French PWR.  Not that I know what “gray” control rods are, but it’s just the sort of flexibility sought in Gen N reactors. 

If I weren’t so lazy I’d reply to Engineer-Poet directly on the gray rods, but it’s sleepy time for me. Maybe he’ll pick it up anyway.





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