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Meeting two degree climate target means 80 per cent of world's coal is unburnable, study says

Posted on 6 February 2015 by Guest Author

This is a re-post from Roz Pidcock at Carbon Brief

More than 80 per cent of the world's known coal reserves need to stay in the ground to avoid dangerous climate change, according to new research. Thirty per cent of known oil and 50 per cent of gas reserves are unburnable and drilling in the Arctic is out of the question if we're to stay below two degrees, the new research notes.

That vast amounts of fossil fuels must go unused if we're to keep warming in check isn't a new idea. What's novel about today's paper is that it pinpoints how much fuel is unburnable in specific regions of the world, from Canadian tar sands to the oil-rich Middle East.

Unburnable carbon

In its most recent report, the Intergovernmental Panel on Climate Change (IPCC) calculatedhow much carbon we can emit and still keep a decent chance of limiting warming to two degrees above pre-industrial levels. This is known as a carbon budget. Two degrees is theinternationally-accepted point beyond which climate change risks become unacceptably high.

As of 2010, we could release a maximum of about  1000 billion more tonnes of carbon dioxide and still have a 50:50 chance of staying below two degrees, according to the  IPCC.

Today's paper compares this allowable carbon budget with scientists' best estimate of how much oil, gas and coal exist worldwide in economically recoverable form, known as "reserves".

Were we to burn all the world's known oil, gas and coal reserves, the greenhouse gases released would blow the budget for two degrees three times over, the paper finds.

Regional breakdown

The implication is that any fossil fuels that would take us over-budget will have to be left in the ground. Globally, this equates to 88 per cent of the world's known coal reserves, 52 per cent of gas and 35 per cent of oil, according to the new research.

The University College London team used a complex energy system model to investigate the fraction of "unburnable" fossil fuel reserves in 11 specific regions worldwide.

The results suggest the Middle East holds half of total global unburnable oil and gas reserves, with more than 260 billion barrels of oil and nearly 50 trillion cubic metres of gas needing to remain untouched if we're to stay within budget. This "unburnable" fraction equates to two thirds of the region's gas and 38 per cent of oil reserves. Russia accounts for another third of the world's total unburnable gas, as the map below shows.

Percentage -usable2

How much oil, gas and coal will we have to leave in the ground to stay under 2 degrees of warming. Credit: Rosamund Pearce, Carbon Brief derived from McGlade et al. (2014)

Coal, the most polluting of the three types of fossil fuel, faces the most restrictive limits. Russia and the US could burn just five per cent or less of their coal reserves if we're to stay below two degrees. In Europe, keeping within budget means 89 per cent of known coal and 21 per cent of oil is unburnable.

Gas plays an important role in replacing coal in the electrical and industrial sectors in a two-degree scenario, the paper notes. According to the analysis, about 94 percent of Europe's gas reserves are still burnable in a two degree world. That's compared to about 30 per cent of the Middle Eastern gas reserves, which are much larger.

It's also worth noting the new model estimates the most cost-effective way to stay below the two degree budget, based on the production costs of the various types of fuel in each region.

So it's not the only way forward and is by no means a prescriptive solution, lead author Dr Christophe McGlade tells Carbon Brief. Instead, he said the research could feed into negotiations as a starting point for wider conversations about historical responsibility, equity and potential compensation mechanisms.

Unconventional gas

It's worth noting, the numbers above relate to known "reserves". These are fossil fuels that have already been discovered and have a high probability of being recovered under current economic conditions. This is different from fossil fuel "resources". These are all the fossil fuels thought to exist which are potentially recoverable irrespective of economic conditions.

Today's research suggests 25 per cent of Europe's unconventional gas resources could feasibly be exploited while still remaining below two degrees. This includes shale gas, tight gas and coal-bed methane. How much of this is economically viable to recover remains to be seen, however.

Should that change in the future, balancing the two degree budget would probably require that more readily available reserves elsewhere would have to go unburned, McGlade tells Carbon Brief.

Turning to the global picture, meeting our two-degree commitment in a cost-effective way means leaving all unconventional oil and 82 per cent of unconventional gas resources in the ground, according to the model. That means Canada's tar sands and the 100 billion barrels of oil estimated to exist in the Arctic would need to go untouched, the paper explains.

Capturing carbon

According to today's research, technology to capture greenhouse gas emissions before they reach the atmosphere would only have a limited impact on the proportion of fossil fuels that can be burned. Carbon Capture and Storage (CCS) would allow just six per cent more of the world's known coal reserves to be burned, with an even lower figure for oil and gas. The paper explains:

"Because of the expense of CCS, its relatively late date of introduction (2025), and the assumed maximum rate at which it can be built, CCS has a relatively modest effect on the overall levels of fossil fuel that can be produced before 2050 in a two-degree scenario".

The new research paints a stark picture of the compromises in fuel use necessary in a climate-constrained world. The researchers say it raises the question of how we divvy up the winners and losers, and that's one we should all now be asking of our policymakers.

McGlade, C & Ekins, P. (2015) The geographical distribution of fossil fuels unused when limiting global warming to 2C. Nature,

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Comments 1 to 20:

  1. But since two degrees is way too high, we really don't have any 'budget.' Our carbon 'budget' is way over drawn. Every extra molecule of carbon put in the atmosphere is a molecule that we'll have to figure out how to get back out of the atmosphere as soon as possible (like, yesterday or last century). And then take many more out thereafter. (All of course without using energy that itself burns carbon...)

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  2. I haven't seen any believable hint that any carbon will stay underground unexplored. Quite the opposite: new frontiers like fracking, Arctic oil, tar sand oil and deepwater drilling suggest that we'll burn even more than all presently known reserves.

    I would love to be proven wrong. Please someone help me out here.

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  3. I hear the term carbon budget a lot lately, but I don't fully understand how it's calculated. I assume it would be related to climate sensitivity, or actually the climate sensitivity specifically for the effects of doubling of CO2 in the atmosphere on global mean surface temperatures. This is currently estimated to be 1.5C to 4.5C. So to compute a carbon budget, we'd look at current CO2 levels (~400 ppm) and pre-industrial values (~280 ppm), pick a reasonable climate sensitvity value like 3C, and plug them into a formula?

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  4. I agree that 2C is way too disastrous. We probably have already crossed it since I don't think the permafrost and methane clathrate contributions have been included although they are virtually certain to have a major impact this century.

    At least some carbon appears likely to stay in the ground with New York, Scotland, Wales, and some European countries banning fracking. Also, there has been a major cut-back in exploration for more carbons. Granted, some of the cut-back is due to low oil prices, but I think some is because of the realization by industry that their reserves will be unsellable. The electric power companies are certainly running scared of PV solar. China may have peaked on coal imports. Improved battery technology with the titanium dioxide anode to the lithium ion battery may dramatically cut the cost and eliminate range anxiety. Fossil fuel cars may soon be fossils. Let's do all we can to make it a reality.

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  5. TomR @4...  Methane contributions certainly have been considered and are thought they will likely not have a major impact this century.

    Peter Sinclair has a very good series of videos with researchers discussing this very issue, called the "Methane Bomb Squad." You should definitely check it out.

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  6. One thing that defiintely should be done right now is a global ban on the burning of the petroleum coke waste that is created when poor grade crude like the stuff in the Alberta Oil Sands is upgraded to a refinable material. That stuff is worse than coal and yet wealthy people are able to profit from it being burned.

    And one thing that is seldom mentioned is the potential future value of unburned buried hydrocarbons. There is the possibility that in the future, thousands or millions of years from now, there could be a really beneficial use for these resources.

    The clear problem is the current marketplace cerated by humans which erroneously relies on popularity and profitability. That system clearly has shown no interest in developing a sutainable better future. The required change of human development will require changes to the motivations of the marketplace. That will only happen through responsible leadership.

    Responsible leadership toward a sustainable better future for everyone has clearly been lacking. It has definitely been possible for irresponsible pursuers of what hey want to create popular support for, and increase the profitability of, damaging activity that cannot be sustained.

    One effective challenge to every defender of getting away with benefiting from burning buried non-renewable hydrocarbons is to demand proof from them that the future generations clearly benefit from the activity they want to benefit from. Ask them to show what they have done to ensure the future generations will definitely have a better life and prove it will actually benefit distant future generations. Even just ask them waht they think future generations will have to do when the non-renewable resources they want to benefit from burning up become even difficult to benefit from.

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  7. It is important to note that the indicated amount of stuff that can be allowed to be burned was not only based on the dangerously high 2 C temperature increase, it was based on a 50:50 chance of a 2 C increase from the amout of burned stuff.

    Structures are not designed with a 50:50 chance of staying up. And vehicle brake systems are not designed to have a 50:50 chance of working when you push the brake pedal. The discussion should be about what is allowed with a 'higher level of certainty that significant problems will not occur'. That would be something better than a 95% level of certainty, something closer to the certainty that human burning of fossil fuels has to be curtailed rapidly in spite of its potential popularity and profitability.

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  8. If you remove fossil fuel subsidies, adopt a useful carbon pricing scheme (ie, not an ETS) and subsidise renewable energy to the same tune that fossil fuels were getting, I get the feeling that a lot of that 80% won't be economically appealing.

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  9. The chances of the "unburnable" fossil fuels remaining unburnt seem very slim indeed. Can you really imagine the scenario "The new research paints a stark picture of the compromises in fuel use necessary in a climate-constrained world. The researchers say it raises the question of how we divvy up the winners and losers, and that's one we should all now be asking of our policymakers playing out in real life?. Just look at the current geopolitical shennanigans over the price of oil and the resultant exultation from consumers. No wondering about their reaction to cheaper fossil fuel. Now try and imagine the public's reaction to oil at $300 a barrel and a 120% increase in power bills and a serious depletion of government largesse due to lack of revenue in countries affected by restrictions on mining and exporting fossil fuels. I also wonder about the advisability of comments such as that from Professor Watson former IPCC Chair and UK governmemt chief scientific adviser "..the world is now most likely committed to an increase in surface temperature of 3C-5C compared to pre-industrial times." The reaction to that by many may well be one of a metaphorical shrug of the shoulders and an "oh well there's nothing we can do about it now so why change" attitude. This doesn't seem a desirable outcome at all. Instead of dire warnings about burning fossil fuels why not put forward a few positive suggestions for alternatives that do not damage the consumer's hip pocket? If the global public can't be convinced that they will not be worse off, then there is no way the long term exploration for and exploitation of, fossil fuels will be significantly reduced. The author's also state "..the research could feed into negotiations as a starting point for wider conversations about historical responsibility, equity and potential compensation mechanisms". As I mentioned above, just look at the conversations OPEC are currently not having about the price of oil and the impact of their actions on revenue in oil exporting countries like Russia and Venezuela. Realistically, pious hopes that " research could feed into negotiations" may well be just that.

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    Moderator Response:

    [JH] An accross-the-board, in-depth analysis of all facets of the energy/climate future of the type that you suggest would require a team of experts to do the work. A summary of the analytic process and its results would result in either a major report, or a book. In other words, you cannot expect a single article to cover all facets of an extremely complex subject.

  10. Am I alone if feeling a slight annoyance that we run the numbers for a 2 degree C limit, but not for, say, one degree? My understanding is that 2 degrees was adopted as a politically pragmatic threshold rather than having any particular scientific significance. What the 2 degree calculations seem to offer us is the illusion that we can burn another 20% of the planet's coal reserves (or oil, in other scenarios) before acting. 

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  11. indus56, Others on this comment string have already shared your concern about the 2 C limit so you are not alone.

    Prior to the Copenhagan meeting in 2009 there was a range of 'suggested limits' with a 1.5 C increase being considered to be a target temperature increase limit. That limit seems to have been generally thought to result in reasonable predictability of the regional consequences and reasonably limit the severity of the consequences.

    In Copenhagen the global leaders had to admit the science indicated that the lack of reduction of impacts by the 'global most fortunate biggest benefiters from burning of fossil fuels' had made limiting impacts to 1.5 C a pointless objective. Rather than fuel the disingenuous but popular argument that 'its too late so why bother', they set a 2 C limit. In Paris they need to actually state how much hydrocarbon needs to stay in the ground and establish a system that will ensure that the best global energy benefit to humanity is obtained from the limited amount of impact allowed.

    There is definitely a need to focus on limiting the human impacts without requiring absolute proof in advance of the exact consequences of not limiting them. A recent article in Nature "Climate policy: Ditch the 2 °C warming goal" presents the case for expanding the focus onto other ways of monitoring human impacts such as warming of the oceans.
    It also suggests that clearer global commitments to real actions such as limiting how much buried hydrocarbons can be burned is more meaningful than a global declaration about a limit of impact to a 2 C increase, even if the basis for the limit is a 2 C increase.

    Essentially, the problem comes down to this. The current global economy has developed vast amounts of undeserved impressions of wealth. It has also made many of the 'most fortunate' addicted to benefiting from the unsustainable and damaging burning. There is tremendous wealth, profitability and popularity opposed to the required change, because many of the current 'most fortunate' are simply undeserving of the type of life they can get away with enjoying and are uwilling to give up any of their potential to enjoy their life in the way they hope to get away with.

    I understand that what I have presented is confrontational, especially to those who want to believe that they should not have to give up any personal benefit, enjoyment, convenience, comfort or excess. However, I believe it is one of the best explanations of what can be seen to be going on. And the best actions against that damaging attitude are the continued efforts to improve the collective understanding of what is going on in the hopes that the majority of humanity will actually care about more than just themselves and their 'maximum possible enjoyment of their life any way they can get away with'.

    Some people will never be convionced to care. They need to be excluded from any discussions about what needs to be done. They are the ones whose actions need to be 'forced to be changed against their will'.

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  12. JH Fair Comment.  I'm not picking holes in the piece per se rather commenting on what, to me, seem rather optimistic hopes that most humans will put self interest anything other than first.  And I do stand by my comment that even suggesting it may be too late to avoid unpleasant consequences of higher global temperatures, could well be counterproductive.  From his post @11 it seems One Planet Only Forever may be the author of the piece as in that post my belief that self interest comes first for many, or even most, humans.  I agree wth the comments of OPOF regarding the antipathy many have to the loss of personal benfits but I would also note that many in the developing world want to get their share of  the benefits they consider cheap energy has brought the developed world.  This is a continuing refrain at the global meetings discussing climate change and one that is hard to effectively counter.

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    Moderator Response:

    [JH] Thanks for the clarification. The OP is a guest post and its author may not be monitoring this comment thread. That is why I chose to come to her defense in a general sort of way.

  13. Indus56 - Agreed. A 2 degree limit will not save the world's coral reefs for instance. Coral will still exist, but the grand structures they have built, and which harbour an estimated one million marine species, will not. 

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  14. Although the current situation appears dire, I do anticipate within the next 15 years, what I think of as "2x4 events" which take the attention of the general public far more forcefully than any scientific result or rhetoric I can muster.  Things that tell ordinary people that there is a real problem and, by the way, who is actually lying to them.      

    Those events will trigger a rise of "Green" principles in politics and "Green" parties to power... but not perhaps the same folks as we know them now, because the focus on CO2 will be sharper, and there are a lot of people even now who recognize the need to build new nuclear power as well as all the renewables we can muster  ( Unless we get good, cheap energy storage systems we are going to need nuclear and almost everyone will know that we do ).

    ...and that will start to happen.  

    So BAU cannot continue as long as we might fear, even though it WILL continue far longer than we wish.    A lot of coal will stay in the ground.  Not as much as we wish.  IMHO we're on for 3 degrees as it stands with a possible 4, but action will start to be taken.   

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  15. Apologies... I need to remember the bold or underline rather than "all caps" rule.  Alas, I learned to do this before there was bold as an option so the habit runs deep.  :-) 

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  16. I have a friend who is a denier.  Calls this a 'religious' argument between the conservative capitalists (deniers) and the liberal/controlled economy (believers)

    One point he makes that I think is valid for a lot of people out there:

    *  In much of the world there is a 10-15 C daily change.  

    *  On top of that a 30-60 degree yearly change.

    *  Why all this fuss about 1-2 degrees?

    Point 2:  

    Currently the oceans are rising at about 3 mm/year.  Assume that the average sea coast area has a slope of 1%  A 3 mm rise translates to about a foot.  Given that any given storm can leave or take 20 feet of shore, who cares about a foot?  Yes, if you live on a barrier island, you may want to sell to some denier.  But a foot a year, isn't unreasonable to cope with.

    Recently a graph of ocean temperatures made the rounds, but the units were 1022 J.  Some calcuation showed that this is something like 0.003 C. The range on the whole graph was 0.08 C.    After reading the sidebar article on measuring deep ocean temperatures, I don't find the article convincing.

    You catch the drift:  For most people it's an intellectual exercise.  It doesn't affect them.  They don't see 1 or 2 or even 5 degrees as making a real difference.

    To counter this:

    1.  Find  comparable regions where the only difference is 2 C in average temperature.  Ideally it should be 2 different for each month.  They should have similar rain fall patterns too.  SHOW people what 2 degrees means with pictures.  Do the same with 5 degrees.

    2.  Repeat this exercise, but use the change in regimes predicted by the current GCMs.  (Most, I think predict more of the warming in winter, and more of the warming at high latitudes.

    3.  Grovel the climate databases, and for the N largest cities in each country, find a matching location for x degrees warmer by the two standards above.  

    This makes it real.  It's not just a number anymore, it's pictures.  

    Consider:  Most people won't change their diet to extend their life.

    Most people will not do a retrofit on their house unless it pays back in under 3 years.  

    I considered installing 5 kW of grid tied PV on my roof.  Would cost me about 15K to do this.  In our climate it would generate about 6000 kWh/yr, worth about $480 at current prices.  That's a 3% return on investment, not counting lost opportunity costs, and not including maintenance.  Power has to get a lot more expensive that 8 c/kWh before I can go this route.  (We are billed separately for wire charges and power here.)


    The second thing that believers need to do is give viable alternatives.  You can say the sky is falling, but tell people where to get umbrellas that will shed sky bits.  

    If you don't do this, then all you do is make people feel anxious for a few minutes, then, when nothing can be done, return to their rut.  

    Solutions have to be practical on large scales.  E.g. Encouraging people to buy electric cars is only going to create a big shortage of lithium.  There is not enough lithium to build all electric cars.  (And there isn't an electric car out there that will let me make a round trip to Edmonton in winter.)

    So:  Make it real.

    Give a call to action that is do-able.

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    Moderator Response:

    [JH] Excessive white space eliminated.

  17. sgbotsford,

    The fact that many people can claim they will not be affected by the impacts of their pursuit of maximum personal comfort, convenience, wealth, and pleasure is not a justification for their preferences. That way of thinking is just a poor excuse to behave unacceptably. It is the equivalent of saying "I enjoy want I want even though I understand all others cannot equally enjoy it into the distant future and even though I understand my enjoyment creates problems others will have to deal with".

    And anyone who demands that until it is cheaper and easier for them to enjoy more than they have gotten accustomed to getting away with does not need to be 'negotiated with'. Their opinion is not relevant to the determination of what needs to be done, and it is not relevant to the continuing development of the understanding of what is going on. Those type of people only deserve the choice to become more considerate, aware and better understanding of what is going on.

    The development of a sustainable economy actually requires much of the perceive current wealth and prosperity to be seen as being undeserved. Excess damaging consumption and waste, particularly the damaging wasteful burning of non-renewable buried hydrocarbons has no place in the future regardless of current perceptions of popularity and profitability.

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  18. Burning European fossil fuel reserves and resources because it reduces transportation costs and because it is a large market, however, it looks suspicious and self serving. I don't think it is at all, they are the most proactive and aware, it just looks that way. Similarly, feedback loops could be greater factors at a lower temperature than expected. Look at deglaciation, IPCC forecasts went from 30 cm of SLR to 95 in a matter of a decade. The earth could be more forgiving, but it could be more angry making our efforts insignificant. We should redouble our efforts and try most avenues, not just conventional efforts. We must stay away from crazy plans, sorry I am not being pejorative, aerosols are a bit crazy for me. I realize Pluvinergy is too complex for me to communicate, but we now have a patent on the works to produce sufficient water to adjust sea level. I know that sounds crazier, but no body has a better plan, and this is amazingly simple, the one big question is if the dry land has suffecient storage, and absorption capacity. Producing the water is easy, the energy is there, is the simplest atmospheric architecture to casue mini-atmospheric rivers in tropical areas to export to subtropical zones. Initial estimates are that the land can accomodate 7.2 million km3, for 20m slr, but that has yet to be peer-considered.

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    Moderator Response:

    [PS] Please refrain from repeated pushing of pluvialenergy. This adds up to excessive repetition in violation of comments policy and is perilously close to spam.

  19. I think it remarkably unlikely that you are going to persuade people to change their lifestyle etc to reduce climate change. Shifting people's political values is very hard. What most strategies are about is pricing the externalities associated with burning fossil fuel, so that non-carbon fuels are cheaper. This takes political will and yes it probably means you will pay more for your energy (which then encourages efficiency). The number one thing to do is stop burning coal. You will have to find a way to live without petroleum at some point anyway.

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  20. Even if widespread decisions are made to reduce the use of fossil fuels as rapidly as possible by shutting down much of the existing infrastructure, the concentration level of greenhouse gases in the atmosphere and absorption in the oceans will continue to rise. Irreversible global (atmoshere and ocean) warming will continue. There is no limit in a applicable time scale.The 2 degree Celsius is only an indicative figure for discussion purposes. It would be more useful if discussions centred on what can reasonably be done to adapt to the inevitable climate change and ocean acidification.

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