Tag Archives: climate change

Climate change: how did we get here, and why is it so hard to fix? (Part 1)

Activities that cause emissions are ubiquitous, diverse and deeply embedded in modern life.  The world’s energy system is huge and long-lived.  This makes emissions tough to deal with. 

This post is the first of two stepping back a little from the specific topics I usually cover to take a very high level look at why the climate change problem is so hard to fix.  This first post looks at how we got here and (at a very high level) the physical and engineering challenges of addressing the climate change problem.  The next post will consider some of the political and psychological barriers to greater action.

The consequence of industrialisation

The world’s climate was remarkably stable from before the birth of agriculture, some 8-10,000 years ago, until very recent times[1].  Human civilisation grew up in a stable climate, and knew nothing else, despite the calamities caused on occasions by storms, floods, drought, and so forth.

Industrialisation changed this.  There is no single year that definitively marks the beginning of industrialisation, but 1776 probably as good a reference point as any.  It was an eventful year, with the US Declaration of Independence giving history one of its most famous dates, while elsewhere the first edition of Adam Smith’s Wealth of Nations was published and the Bolshoi Theatre opened its first season.  But in the long view of history perhaps more important than any of these was that James Watt’s steam engines began to power industrial production[2].  This, more than any other event, marks the beginning of the industrial era.

In the nearly two and a half centuries since 1776, world population has grown by almost a factor of about 10.  Economic output per person has also grown by a factor of about 10.  Taking these two changes together, the world’s economic activity has increased by a factor of about 100.  This has put huge stresses on a range of natural systems, including the atmosphere[3],[4].

The increase in the use of fossil fuels has been even greater than the increase in industrial activity.  Around 12 million tonnes of fossil fuels, almost entirely coal, were burnt each year before 1776[5].  Today the world burns about 12 billion tonnes of fossil fuels each year, an increase of a factor of 1000[6].

This huge increase in the burning of fossil fuels is now – together with deforestation, agriculture and a few other activities – changing the make-up of the atmosphere on a large scale.  This in turn, is changing the world’s climate.   Within a single human lifetime – just one percent or so of the time since the birth of agriculture – changes to the climate are likely to be much greater than human civilisation has ever before experienced.  The consequences of these changes are likely to be largely harmful, because manmade and natural systems are largely adapted to the world we have, not the one we are making.

The characteristics of the systems that have led to these changes also make the problems hard to address.

The scale of emissions is huge …

The scale of CO2 emitted from the energy system is vast, around 36 billion tonnes p.a.  If this were frozen into solid form as “dry ice” it would cover the whole of Manhattan Island to the depth of about two thirds of the Empire State building.

The system that generates these emissions is correspondingly huge.  The world’s energy system cost tens of trillions of dollars to build, and is correspondingly immensely expensive to replace.

The diversity and dispersion of emissions makes the problem more challenging …

The problem is worse even than its scale alone suggests.  It would be simpler to deal with emissions if they were all in one place, whether Manhattan or elsewhere, and in solid form.  Instead emissions are dispersed across billions of individual sources around the world.  And they come from many different types of activity, from transporting food and powering electronics to heating and cooling homes and offices.  There is no single technology doing one thing to be replaced, but a wide diversity of technologies and applications.

And once emissions get into the atmosphere the greenhouse gases are very dilute.  Carbon dioxide makes up only 400 parts per million (0.04%) of the atmosphere.  Among other things this makes capture of CO2 once it has got into the atmosphere difficult and expensive.

And assets producing emissions are very long lived …

Energy infrastructure often lasts many decades, so changing infrastructure tends to be a long term process, with premature replacement expensive.  And on the whole the existing system does its job remarkably well.  There would be little need for very rapid changes to the system if it were not for climate change and other forms of pollution.

Energy is central to modern life …

Finally it’s not possible to simply switch off the world’s energy system because it is essential to modern life.  Hurricane Sandy disrupted much of New York’s energy system, and the consequences of that gave an indication of how quickly modern life collapses without critical energy infrastructure.

These physical characteristics of the problem are compounded by the political and psychological obstacles to change at the necessary scale.  I will return to these in my next post.

Adam Whitmore – 22nd May 2017


[1] This climatically stable period since the end of the last ice age between 11,000 to 12,000 years ago is referred to as the Holocene.  Agriculture started not long after the ice sheets retreated and the world warmed.  Human activity has now led to a new period, referred to as the Anthropocene.

[2]   https://en.wikipedia.org/wiki/Watt_steam_engine.  The first use of the Watt engine to provide the rotary power, which was crucial for factories, was a little later in 1782 at the Soho manufactory near Birmingham.  https://en.wikipedia.org/wiki/Soho_Manufactory.

[3] http://www.scottmanning.com/content/year-by-year-world-population-estimates/

[4] http://www.ggdc.net/maddison/maddison-project/data.htm

[5]Reliable data is obviously hard to come by that far back, but See Energy for a Sustainable World: From the Oil Age to a Sun-Powered Future By Vincenzo Balzani, Nicola Armaroli .  They estimate 10 million tonnes in 1700 and 16 million tonnes by 1815.  The majority of the increase would have been in the later part of this period.  See also Socioecological Transitions and Global Change, edited by Marina Fischer-Kowalski, Helmut Haberl, who quote estimates of 3 million tonnes p.a. in 1700 in the UK, a large proportion of the world total at the time, with little increase to 1776.  This consumption included a few primitive, inefficient steam engines, used mainly for pumping water from coal mines themselves.  The Newcomen steam engine required such large quantities of coal that it was rarely economic to site it away from coal mines.  The Watt engine was more than twice as efficient.

[6] My estimate of the total mass of coal, oil and gas, based on data in BP statistical review of World Energy.

A wealth of ideas about wealth funds

There are many ways of designing a wealth fund based on revenues from carbon pricing.  Debate about these is necessary, but should not distract from the merits of the broader proposal. 

Last month I outlined the value of the carbon emissions, and the possibility of establishing a wealth fund based on revenue from carbon pricing.  This post provides some brief responses to questions that have been raised in response to this proposal.   There are many good design options to choose from.

Would the fund necessarily be national?

No.  There are many national wealth funds in operation, and national carbon wealth fund may well be a pragmatic way forward in many cases.  However, the Alaskan wealth fund is an example of a state based scheme, and others would be possible.  In the EU a fund could also be established either at EU or Member State level.  An international fund would be difficult and perhaps impossible to establish, but would appropriately reflect global nature of the climate change problem.

How would such a fund be governed?

There are many options here.  The most important criterion is that governance should benefit the ultimate owners of the asset, namely citizens, rather than the state or special interest groups.  This implies some independence from government.  Other criteria such as transparency and ethically sound investment will also be important[1].  Some have advocated a fully independent trust fund.  However in practice some degree of government oversight is likely to be required[2].

How would this global public good be allocated internationally?

The distribution between nations of access to the atmosphere has proved a major point of contention in global negotiations on limiting climate change, and this situation appears unlikely to change[3].  However existing carbon pricing regimes – or simply emitting free of charge – already use up a global public good.  Giving citizens and governments a greater stake in increased carbon prices is likely to decrease the quantity of emissions, and so the proportion of the global commons used[4].  This makes the approach I have proposed more compatible with good stewardship of the global commons than existing arrangements, at least for the next 50 years until revenues start to decline.

What would the macro-economic effects be?

These effects would probably not be large, at least for a national UK fund.  The payment into a UK fund would be at most around £16 billion p.a. assuming much greater coverage and higher carbon prices than at present, a little under 1% of GDP per annum[5].  Even this would be unlikely to cause major economic dislocation, especially if phased in over a few years.  The fund would grow large over time, reaching around £860 billion by the end of the century, depending on many factors including which other environmental taxes were included  [6].  However this is not vastly larger than the Norwegian fund today, which is for a very much smaller economy.  Furthermore any fund would have the effect of redirecting revenue from consumption to investment, which would probably have a positive macroeconomic effect in the context of historic UK underinvestment.

Would such a measure be socially regressive?

The concern here is that poorer households spend a larger proportion of their income on energy than richer households, and so energy taxes, and thus carbon taxes, tend to hit them disproportionately harder.  However poor households still spend less on energy, and therefore carbon, in absolute terms than richer households, so an equal dividend, as I’ve proposed, would have a net progressive effect.   Furthermore, households account for only a minority of energy use, but would get the full benefit of dividends (or at least a large proportion), increasing the extent to which it is progressive.

However there are some important intergenerational issues to consider.   The proposal for a fund takes the view that present generations should safeguard capital assets so they retain value to future generations.  This is in line with the standard definition of sustainable development[7].  However there are distributional issues here which need to be addressed.  Some present citizens will be worse off.

How would it fit with other green taxes?

The proposal is clearly consistent with using green taxes more widely as a policy instrument.  What’s different from the standard approach to green taxes is the suggestion of placing revenue in capital fund rather than using revenue to fund current expenditure.  The landfill tax to which I referred in my original post currently raises around a billion pounds per annum[8].  It would be natural to add this revenue to a UK wealth fund.

Would distribution to citizens be the only use for funds?

There is no reason some of dividends from the fund should not be used to fund things like R&D.  As I have previously discussed there are many legitimate calls on revenue from carbon pricing.  However there are many compelling arguments for allocation direct to citizens, and this should in my view be a priority for the fund.

Each of these questions requires further elaboration of course, and there are many other questions to be resolved.  The design of any major new institution such as a carbon wealth fund will require a great deal of consideration of a range of issues.  However further examination appears to strengthen rather than weaken the case for such a fund.

Adam Whitmore – 22nd  March 2017

Thanks to John Rhys for raising some of these issues.  A variant of this post, responding to John’s points, was published on his website. 


[1] See Cummine (2016) cited in my original post for further details For a specific proposal for a UK wealth fund:  http://www.smf.co.uk/press-release-conservative-mp-calls-for-uk-sovereign-wealth-fund-to-address-long-term-and-structurally-ingrained-weaknesses-of-the-economy/

[2] See Barnes, Who Owns the Sky (2001)

[3] This problem does not arise for the conventional resources (such as oil and gas) that typically provide the income for sovereign wealth funds of the nations where the resources are located. There is an interesting question as to whether countries should have full property rights to natural resources within their territories, as is often assumed at present, but this is too large a subject to go into here.

[4] The assumption here is that increasing prices from current low levels will increase revenue.  Carbon prices would increase by a factor of say five or more in many cases, and it is unlikely that emissions would decrease by an equal factor – though if they did it would be very good news.

[5] This assumes 400 million tonnes of emissions are priced, compared with 2015 totals of 404 million for CO2 emissions and 496 total greenhouse gases (source: BEIS), implying a high proportion of emissions are assumed to be priced.  The carbon price is assumed to be £40/tonne, roughly the Social Cost of Carbon at current exchange rates and well above current price levels.  This would give total revenue of £16 billion in the first year based on both volumes and prices substantially greater than current levels, but still less than 1% of UK GDP of approximately £1870 billion in 2015. (source: https://www.statista.com/statistics/281744/gdp-of-the-united-kingdom-uk-since-2000/ )

[6] Assuming that the UK reduces its emissions in line with the Climate Change Act target of an 80% reduction from 1990 levels by 2050, and then to zero by the end of the century, and that 80% of emissions are priced at the Social Cost of Carbon as estimated by the US EPA, converted at current exchange rates of $1.25/£.

[7] Sustainable development is usually characterised as meeting the needs of present generations without compromising the ability of future generations to meet their own needs.

[8] https://www.uktradeinfo.com/Statistics/Pages/TaxAndDutybulletins.aspx

Reform of the EUETS has at last made significant progress

The effective limit on the size of the MSR proposed by Council is an extremely welcome strengthening of the EUETS.  However it will still take a long time for the EUETS to become fully effective.

This post updates last week’s post to reflect the important agreement on the EUETS reached in Council earlier this week.  On Tuesday the Environment Council endorsed more ambitious EU ETS policy changes than those agreed by the European Parliament.  This surprised many observers (including me) and is a very welcome change.

The most important change is an effective limit on the size of the Market Stability Reserve (MSR).  Allowances held in the MSR will be cancelled if the MSR contains more than the previous year’s auction volumes, although the precise interpretation of this remains to be defined.   In effect this change means that the number of allowances in the MSR is unlikely to be more than about 500 -700 million after the limit takes effect in 2024.  Indeed the volume limit is tighter than I had previously expected to be possible when I was advocating a size limit on the MSR last June (see here).

The huge size of the MSR during Phase 4 means that this reform will likely result in a cancellation of about 3 billion tonnes from the MSR over Phase 4 (see chart).  Much of this 3 billion tonnes will go into the MSR in 2019, and will be cancelled in 2024 if the reform is finally adopted.

Chart:  The proposed reform will likely lead to cancellation of around 3 billion tonnes from the MSR


Notes:  Uses base case emissions (see previous post), assumes 57% auctioning, and assumes all unallocated Phase 3 allowances go into MSR in 2020.  EP MSR is the MSR under the European Parliament proposals.  New MSR is with the new proposals from Council.  Source: Sandbag

Despite this proposal the market is likely to remain weak for a long time.  Emissions will remain below the cap until the middle or the end of the next decade, and perhaps for longer.  Volumes are not in any case likely to begin returning from the MSR until close to 2030, so the size limit will probably begin to bite in the 2030s.  Tightening the cap to reflect actual emissions remains essential for a well-functioning EUETS over the next few years, and additional measures to complement the EUETS will continue to be necessary (see my previous post for more on these points).   Indeed this reform increases the value of additional action as it implies that additional surplus allowances will indeed be cancelled, leading to greater reductions in cumulative emissions.

Nevertheless, despite its limitations, this reform is a substantial and very welcome strengthening of the EUETS.  Even though the market will still take many years to tighten, this reform is likely to have some influence on earlier prices as traders anticipate a tighter market.  Indeed, in contrast to the measures coming out of Parliament, the market responded immediately to the vote (prices temporarily increased €1/tonne, about 20%).   It is highly desirable that this reform is retained through the remainder of the legislative process.

Adam Whitmore  – 3rd March 2017

Thanks to Boris Lagadinov at Sandbag for useful discussions and providing the chart for this post.

Can emissions trading produce adequate carbon prices?

Prices under emissions trading schemes have been low to date.  Sometimes this may be because systems are new, but the EUETS is long established and needs to demonstrate that it can now produce adequate prices. 

Prices under emissions trading systems around the world have so far remained low.  The chart below shows carbon pricing systems arranged in order in increasing price, with prices on the vertical axis shown against the cumulative volume covered on the horizontal axis.  Carbon taxes are shown in purple, emissions trading systems in green.  It is striking that all of the higher prices are from carbon taxes, rather than emissions trading systems.

Prices under Emissions Trading Systems and Carbon taxes in 2016


Source:  World Banks State and Trends of carbon pricing report[1].  Prices are from mid-2016.

Prices in the largest emissions trading system, the EUETS have been around $5-6/tonne, and prices in the Chinese pilot schemes have been similar and in some cases even lower, although with little trading.  The price under the California and Quebec scheme (soon to be joined by Ontario) is somewhat higher.  However, this is supported by a floor set in advance and implemented by an auction reserve price.  If this price floor were not present a surplus of allowances would very likely have led to lower prices.  The Korea scheme has had very low trading volumes, so does not provide the same sort of market signal found under more liquid schemes.

In contrast, a wide range of carbon taxes are already at higher levels and in some cases are due to increase further.  The French carbon tax, which covers sectors of the economy falling outside the EUETS, is planned to reach €56/tCO2 (US$62/tCO2) in 2020 and €100/tCO2 (US$111/tCO2) in 2030[2].  In Canada a national lower limit on carbon prices for provinces with an explicit price-based system (not shown on the chart) is due to reach $50 per tonne in 2022[3]. The UK carbon price floor, which covers power sector emissions, was due to rise to substantially above current levels, but is currently being kept constant by the Government, mainly because the price under the EUETS is so low.

Increases such as those due in France and Canada will bring some carbon taxes more in line with the cost of damages, and thus to economically efficient prices.  The cost of damages is conservatively estimated at around $50/tonne[4], rising over time (see here for a discussion of the social cost of carbon and associated issues).  The increases will also bring prices more into line with the range widely considered to be necessary to stimulate adequate low carbon investment[5].

Low prices under emissions trading systems have been attributed to a range of factors, including slower than expected economic growth and falling costs of renewables[6].  However these factors do not explain the consistent pattern of low prices across a variety of systems over different times[7].

While it is difficult to derive firm evidence on why this pattern should be present, two factors seem plausible.  The first is systematic bias in estimates – industry and governments will expect more growth that actually occurs, costs will be overestimated, and these tendencies will be reflected in early price modelling, which can often overstate likely prices.

But the second, more powerful, tendency appears, based on anecdotal evidence, to be that there is an asymmetry of political risk.  The political costs of unexpectedly low prices are usually perceived as much less than those of unexpectedly high prices, and so there will always be tendency toward caution, which prevents tight caps, and so leads to prices being too low.

This tendency is difficult to counteract, and has several implications for future policy.

First, it further emphasises the value of price floors within emissions trading systems.  Traditional environmental economics emphasises the importance of uncertainty around an expected level of abatement costs or damages.  If decision makers are not in fact targeting expected average levels, but choosing projections of allowance demand above central expectations then the probability of very low prices is increased, and the case for the benefits of a price floor is stronger.

Second, it implies that it is even less appropriate than would anyway be the case to expect the carbon price alone to drive the transition to a low carbon economy.  Measures so support low carbon investment, which would in any case be desirable, are all the more important if the carbon price is weak (see here for a fuller discussion of the value of a range of policy measures).   While additional measures do risk further weakening the carbon price, they should also enable reduced emissions and tighter caps in future.

Third, it requires governments to learn over time.  Some low prices may reflect the early stage of development of systems, starting slowly with the intention of generating higher prices over time.  However this does require higher prices to eventually be realised.

The EUETS has by some distance the longest-established system, having begun eleven years ago and with legislation now underway for the cap to 2030, by which time the system will be 25 years old.  The EU should be showing how schemes can be tightened over time to generate higher prices.  However it now looks as though the Phase 4 cap will be undemanding compared with expectations (see previous posts).  The recent vote by the European Parliament’s ENVI committee failed to adopt measure that are adequate to redressing the supply demand balance, with tweaks to the market stability reserve unlikely to be enough.  This undermines the credibility of cap-and-trade systems more generally, rather than setting the example that it should.  Further reform is needed, including further adjustments to supply and preferably auction reserve prices.

The advantages of cap-and trade systems remain.  Quantity limits are in line with the international architecture set by the Paris Agreement.  They also provide a clear strategic signal that emissions need to be reduced over time.

However there is little evidence to date that emissions trading systems can produce adequate prices. The EU, with by far the most experience of running an ETS, should be taking the lead in substantially strengthening its system.  At the moment this leadership is lacking.  Wider efforts to tackle climate change are suffering as a result.

Adam Whitmore – 23rd January 2017

[1] https://openknowledge.worldbank.org/handle/10986/25160

[2] World Bank State and Trends in Carbon Pricing 2016.  See link in reference 1.

[3] http://news.gc.ca/web/article-en.do?nid=1132169  Canadian provinces with volume based schemes such as Quebec with its ETS must achieve emissions reductions equivalent to these prices.

[4] $40/tonne in $2007, see https://www.epa.gov/climatechange/social-cost-carbon, escalated to about $50 today’s dollars.

[5] See this recent discussion: https://www.weforum.org/events/world-economic-forum-annual-meeting-2017/sessions/the-return-of-carbon-markets

[6] Ref: Tvinnereim (2014) http://link.springer.com/article/10.1007%2Fs10584-014-1282-1#page-1


[7] The South Korea ETS may be a partial exception to the pattern.  However it is unclear due to the lack of liquidity in the market.

Additional actions in EUETS sectors can reduce cumulative emissions

It is often claimed that additional actions to reduce greenhouse gas emissions in sectors covered by the EUETS are ineffective because total emissions are set by the level of the cap.  However this claim is not valid in the current circumstances of the EUETS, and is unlikely to be so even in future.  Additional emissions reduction measures in covered sectors can be effective in further permanently reducing emissions.

This post is longer than usual as it deals with a very important but relatively technical policy issue.

The argument about the effectiveness of additional actions to reduce emissions …

Many additional actions are being taken to reduce greenhouse gas emissions in sectors covered by the EUETS.  These include energy efficiency programmes, deployment of renewables, replacing coal plants with less carbon intensive generation, and national carbon pricing.

It is often argued that such additional actions do not reduce total emissions because the maximum quantity of emissions is set by the EUETS cap, so emissions may remain at the fixed level of the cap, irrespective of what other action is taken (see the end of this post for instances of this argument being used publicly).

However, this argument does not stand up to examination.

Assessment of the argument needs to take account of the current circumstances of the EUETS.  Emissions covered by the EUETS were some 200 million tonnes (about 10%) below the cap in 2015.  This year emissions are likely to be 13% below the cap.  The EUETS currently has a cumulative surplus of almost three billion allowances, including backloaded allowances currently destined for the Market Stability Reserve (MSR), and the surplus is set to grow as emissions continue to be less than the cap.

In these circumstances emissions reductions from additional actions will mainly increase the surplus of allowances, with almost all of these allowances ending up in the (MSR).  These allowances will stay there for decades under current rules, and so not be available to enable emissions during this time.

Indeed, in practice these allowances are unlikely ever to enable additional emissions.  The argument that they will assumes that the supply of allowances is fixed into the long term.  In practice this is not the case.  Long term supply of allowances is determined by policy, which can and does respond to circumstances.  Additional surpluses and lower prices are likely to lead to tighter caps than would otherwise be the case, or cancellation of allowances from the MSR or elsewhere.

The remainder of this post looks at these issues in more detail, including why the erroneous view that additional actions don’t reduce cumulative emissions has arisen.

Why current circumstances make such a difference

The argument that additional actions to reduce emissions will be ineffective reflects how the EUETS was expected to operate when it was introduced. It was assumed that demand for allowances would adjust so that the quantity of allowances used would always equal to the cap, which was assumed to be fixed.

This is illustrated in stylised form in the diagram below.  The supply curve is vertical – perfectly inelastic supply.  Demand for allowances without additional actions leads to prices at an initial level.  Additional actions reduce demand for allowances at any given price, effectively shifting the demand curve to the left by the amount by which additional actions reduce emissions.  This leads price to fall until the lower price creates sufficient additional demand for allowances, so that total demand for allowances is again equal to the supply set by the cap.  Because the supply curve is fixed (vertical) the equilibrium quantity of emissions is unchanged, remaining equal to the cap[1].

Chart 1: A price response to the change in demand for allowances can lead to emissions re-equilibrating at the cap when allowances are scarce …


However, at present, large increases in emissions (such that emissions rise to the cap) due to falling prices are clearly not occurring, and they seem unlikely to do so over the next few years.  As noted above, the market remains in surplus both cumulatively and on an annual basis.  The price would be close to zero in the absence of banking of allowances into subsequent phases, because there would be a cumulative surplus over Phase 3 of the EUETS, and so no scarcity[2].

If demand were further reduced in the absence of banking there would be no price fall, because prices would already be already close to zero.  Correspondingly, there would be no increase in demand for allowances to offset the reduced emissions from additional actions.  The emissions reductions from additional actions would be retained in full. This is again illustrated in stylised form in the diagram below. 

Chart 2: With a surplus of allowances and price close to zero (assuming no banking) any reduction in demand for allowances will be retained in full …


In practice the potential to bank allowances and the future operation of the MSR supports the present price.  It is expected that in future as the cap continues to fall allowances will become scarce.  There is thus a value to allowances set by the cost of future abatement.

Additional actions now to reduce emissions increase the surplus, and so postpone the expected date at which the market returns to balance.  This reduces current prices.  This will in turn lead to some increase in emissions.  However, this increase will be small – much smaller than if the market were short of allowances now.

Quantifying this effect 

Modelling indicates that if additional actions are taken over the next 10-15 years, then the increase in demand for allowances due to falling price will be less than 10% of the size of the reduction in emissions[3].  Correspondingly more than 90% of the emissions reductions due to additional actions are retained, adding to the surplus of allowances which, which end up in the MSR.  Modelling parameters would need to be in error by about an order of magnitude to substantially affect this conclusion.

This effect arises in part because of the low level of prices at present.  This means that even a large percentage change in price leads to a small absolute change, and thus a small effect on demand for allowances.  Even a 50% price fall would be less than €3/t at current price levels.  It also reflects that the shape of the Marginal Abatement Cost curve, with price falls only increasing abatement by a small amount.  This means that even if prices are higher than current levels the effect of price falls on demand for allowances is still relatively small.

The relatively small response to price changes is consistent with the current market, where there is a lack of sufficient increase in demand to absorb the current yearly surplus (or even to come close to doing so).

The 90%-plus of the allowances freed up by additional actions are added to the surplus end up over time in the MSR.  They then stay there for several decades.  This is because even without additional actions, and even with some reform of the current proposals for Phase 4 (which covers 2021 to 2030), the MSR is likely contain at least three billion allowances by 2030, and perhaps as much as five billion.  This will take until 2060 to return to the market, and perhaps until the 2080s, at the maximum rate written into the legislation of 100 million per annum.

Any additional surplus will only return after this.  Even if the return rate of the MSR were doubled the return time for additional surplus would still be reckoned in decades from now.

This will be even more the case if proposals for the EUETS Phase 4 are not reformed, and the surplus of allowances being generated anyway is correspondingly greater.

The implications of the very long delay in the return of allowances

It seems unlikely that allowances kept out of the market for so long would ever lead to additional emissions.  It would require policy makers to allow the allowances to return and enable additional emissions.  This would be at a time when emission limits would be much tighter than they are now, and indeed with a commitment under the Paris Agreement to work towards net zero emissions in the second half of this century.

There are several policy mechanisms that could prevent the additional surplus allowances enabling emissions.  Subsequent caps tighter as unused allowances reduce the perceived risk of tighter caps, and additional actions now set the economy on a lower carbon pathway.  Furthermore, with a very large number of allowances in the MSR over several phases of the scheme, allowances may well be cancelled.  Indeed, over such long periods the ETS itself may even be abolished or fundamentally reformed, with allowances not carried over in full.  Or a surplus under the EUETS may persist indefinitely as additional actions succeed in reducing emissions.

As the market tightens towards 2030 it is likely that a higher proportion of any additional emissions reductions will be absorbed by the market via a price effect, but it still seems unlikely to be as much as 100% given the long term trend to lower emissions and the lack of additional sources of demand, especially in the event of large scale additional actions[4].  Some of the policy responses described would still be expected to reduce the supply of allowances.


The argument that emissions will always rise to the level of the cap manifestly does not hold at present, when emissions are well below the cap. and there is a huge cumulative surplus of allowances.

In future, it seems likely that more than 90% of reductions in emissions from additional actions will simply add to the surplus, and eventually end up in the MSR.  They at least stay there for several decades, because of the very large volume that will anyway be in the MSR.

While there is in principle a possibility that they will eventually return to the market and allow additional emissions this appears most unlikely in practice.  Policy decisions will be affected by circumstances and this can readily prevent additional emissions, through some combination of tightening of the cap and cancellation of allowances.

Even when the market returns to scarcity these policy responses are likely to hold to a large extent, for example with lower prices enabling more stringent caps.  The hypothesis of no net reductions in emissions from additional actions thus seems unlikely ever to hold true.

Spurious arguments about a lack of net emissions reductions should not be used as a pretext for failing to take additional actions to reduce emissions now.

Adam Whitmore – 21st October 2016


Note:  A more detailed review of the issues raised in this post, and the accompanying modelling can be found in this report.


Examples of statements invoking the idea of fixed total emissions

For example, in 2015 RWE used such arguments in objecting to the closure of coal plant:

“The proposals [to reduce lignite generation] would not lead to a CO2 reduction in absolute terms.   [The number of] certificates in the ETS would remain unchanged and as a result emissions would simply be shifted abroad.” [5]

Similarly, in 2012 the then Chairman of the UK’s Parliament’s Energy and Climate Change Select Committee, opposed the UK’s carbon price support mechanism for the power sector arguing that:

“Unless the price of carbon is increased at an EU-wide level, taking action on our own will have no overall effect on emissions”[6]

Neutral, well-informed observers of energy markets have also made this case.  For example, Professor Steven Sorrel of Sussex University recently argued that:

“Any additional abatement in the UK simply ‘frees up’ EU allowances that can be either sold or banked, and hence used for compliance elsewhere within the EU ETS[7]



[1] This is analogous to the well-established rebound effect for energy efficiency measures.  Improved domestic insulation lowers the effective price of energy, so consumers take some of the benefits as increased warmth, and some as reduced consumption.  The argument here is that in effect there is a 100% rebound effect for emissions reductions under the EUETS.

[2] Such a situation occurred towards the end of Phase 1 of the EUETS (2005-7), which did not allow banking into Phase 2.  Towards the end of the Phase there was a surplus of allowances and the price fell to close to zero.

[3] The price change is modelled by assuming the price is set by discounting future abatement costs, with a later date for the market returning to balance leading to greater discounting and so a lower price.  The increase in demand for allowances is modelled based on a marginal abatement cost curve and consideration of sources of additional demand.  See report referenced at the end of this post for further details of the modelling.

[4] There are likely to be path dependency and hysteresis effects in the market which prevent a full rebound.

[5] See RWE statement, “Proposals of Federal Ministry for Economic Affairs and Energy endanger the future survival of lignite”, 20 March 2015. http://www.rwe.com/web/cms/en/113648/rwe/press-news/press-release/?pmid=4012793

[6] http://www.parliament.uk/briefing-papers/sn05927.pdf

[7] http://www.energypost.eu/brexit-opportunity-rethink-uk-carbon-pricing/

Reflecting reality in the EUETS Phase 4 cap

The cap for Phase 4 of the EUETS, which runs from 2021 to 2030, needs to start at a level that matches the reality of emissions in 2020, rather than starting where the Phase 3 cap finishes.   

The EUETS surplus will continue to grow through under current proposals …

The surplus of allowances in the EUETS looks to set to get worse with the Commission’s current proposals for the Phase 4 cap, which covers the period 2021 to 2030.   In 2015 emissions covered by the EU ETS were already below the level of the cap for 2020[1].  Emissions are expected to continue falling through the remainder of this decade, driven mainly by increasing deployment of renewables and weak electricity demand.  By 2020 emissions look likely to be over 10% below the cap at the end of Phase 3 (see chart).   This will lead to additional surplus allowances generated from the start of Phase 4, continuing through all or most of Phase 4.   This will in turn lead to the EUETS remaining weak even in the presence of the Market Stability Reserve (MSR).

Chart 1:  Currently proposed cap against emissions forecasts and 2020 gap to cap

Chart 1

This problem arises in large part because the starting point for Phase 4 cap is out of date.   It was effectively set in 2010 as part of the cap for Phase 3, because the EUETS Directive implicitly assumes that the Phase 4 cap will simply continue from where the Phase 3 cap finishes.   However the Phase 3 cap was set before many subsequent trends were known, including the growth of renewables and the length and depth of the economic recession.  Consequently it does not form a suitable starting point for Phase 4, and now looks far too loose.

This problem can be mitigated by changing the starting point of the Phase 4 cap …

The Phase 4 cap needs to start at a level that reflects actual emissions (if this is, as expected, below currently proposed level, which would act as an upper bound in any case).   Rebasing the cap in this way would lead to a much more effective EUETS that delivers effective signals for emissions reductions and investment.  Without this sort of reform the EUETS risks being reduced to little more than an accounting tool, with a chronic surplus and individual Member States increasingly taking their own action to ensure the necessary investment.

This increases the robustness of the mechanism and is more effective than changing the Linear Reduction Factor ….

Rebasing to actual emissions increases robustness of the system by making it dependent on actual outcomes.  Aligning the cap with actual emissions also tightens the cap more quickly and more effectively than changes to the Linear Reduction Factor (LRF – the amount of annual emission reductions built into the EU ETS during the phase).   This is shown in the chart below.

The LRF would need to approximately double from the currently proposed value of 2.2%, to 4.2%, to have the about the same effect on cumulative number of allowances over Phase 4 as rebasing the cap, even in a high emissions case.  And an even greater LRF would be needed to match the effect of rebasing if emissions by 2020 are low.  Even then, changing the LRF reduces the level of the cap more slowly than changing the starting point of the cap.  However increasing the LRF in addition to rebasing the cap helps ensure that surpluses are eroded and do not re-emerge through Phase 4, and so increasing the LRF remains a useful complement to rebasing the cap.

Chart 2.  Decrease in the total Phase 4 cap relative to the current proposal

Chart 2

Rebasing the cap is consistent with a range of precedents …

This approach of adjusting caps to reflect the reality of actual emissions, where these diverge from earlier expectations, has been applied elsewhere.  For example, in the Regional Greenhouse Gas Initiative (RGGI) in the USA, the cap was reduced from 165 million short tons in 2012-3 to 91 million short tons in 2014 to more closely reflect actual emissions[2].  As a result, prices have moved away from the auction floor price, where they were had previously been stuck.

Looking beyond carbon markets, incentive-based regulation of electricity, gas and water network charges in the UK in the 1990s imposed price caps typically lasting five years.  In practice, costs fell more rapidly than was expected when the price cap was set, leading to high margins of price over cost.  One-off cuts in the level of prices, referred to as P0 cuts, were implemented at the start of the next phase of the price control to realign the price cap with outturn costs, and thus capture the benefits of efficiency gains for consumers.

The new starting point for Phase 4 would also be closer to that which was envisaged under the December 2008 European Council Conclusions[3] in case an international agreement was reached and the EUETS would start from a reduction of 30% from 2005 levels by 2020.  A 30% reduction from 1990 would, assuming the EU ETS cap to have been reduced in line with the reduction in other sectors, have led to a starting point for the Phase 4 EU ETS cap of approximately in line with emissions now expected.  This was made conditional on action by other countries.  Commitments to such action have now been made under the Paris Agreement.


With the cap proposed by the Commission the EUETS seems likely to continue providing a largely ineffective signal for abatement well into the 2020s and possibly beyond.   This would mean that by 2030 the  EUETS will have been in existence for a quarter of a century, but will have provided an effective price signal for only a short period in the early part of Phase 2 (around 2009).

A simple adjustment to bring the cap at the start of Phase 4 into line with the reality of emissions would go a long way towards solving this problem by reducing the Phase 4 cap, likely by around 2 billion tonnes or more over the 10 years of the phase.   There are few easier and more natural adjustments to the scheme which could have such an impact.

Adam Whitmore – 20th  June 2016

Thanks to Boris Lagadinov for providing the analysis shown in this post.   This post is based on a recent paper Boris and I wrote for Sandbag – see http://www.sandbag.org.uk

[1] The cap for 2020 is 1816 MtCO2 excluding the effects of backloading.  Emissions were 1802 MtCO2 in 2015.

[2] https://www.rggi.org/design/overview/cap

[3] http://www.consilium.europa.eu/uedocs/cms_data/docs/pressdata/en/ec/104692.pdf

Deploying CCS on fossil fuel plant is more of a priority than implementing negative emissions technologies

The potential for biomass with CCS and direct air capture of CO2 should not distract from deployment of CCS on fossil fuel plants over the next few decades.  Among other things, learning from CCS on fossil fuels will help make eventual deployment of CCS on biomass cheaper and more effective.

There appears to be increasing likelihood that atmospheric concentrations of greenhouse gases will grow to exceed levels consistent with the target specified in the recent UNFCCC Paris agreement of limiting temperature rises to “well below” two degrees.  Such an outcome would require CO2 to be removed from the atmosphere faster than natural sinks allow, in order to restore concentrations to safe levels.  Near zero net emissions in the latter part of this century will also be needed to stabilise concentrations.

Many models of future emissions pathways now show negative emissions technologies (technologies that result in a net decrease in CO2 in the atmosphere) needing to play a major role for in meeting climate goals. They have the potential to remove carbon dioxide from the atmosphere in the event of “overshoot” of target atmospheric concentrations, and to balance remaining emissions from sectors where abatement is difficult with a view to achieving net total emissions of close to zero.  But the application of such technologies should not be considered in isolation.

Bio Energy with CCS (BECCS)

Bio energy with CCS (BECCS ) is the most widely discussed approach to negative emissions.  BECCS is not a single technology but a combination of two major types of CO2 removal.  Bioenergy from burning biomass to generate electricity or heat emits a substantial amount of CO2  on combustion – around as much as a coal plant.  However much of this can be captured using CCS.  More carbon dioxide is reabsorbed over time by the regrowth of the plants, trees – or perhaps algae – that have been harvested to produce the bioenergy.  Together, the capture of the CO2 from the flue gas and the subsequent absorption of CO2 from the atmosphere by regrowth of biomass can lead to net removal of CO2 from the atmosphere, although this takes time.  (The net amount of CO2, that is emitted on a lifecycle basis from burning biomass without CCS depends on the type of biomass and is subject to considerable variation and uncertainty – a controversial topic that would need another post to review.)

However at an energy system level, where the CO2 is captured – biomass plant or fossil fuel plant – is less relevant than the total amount that’s captured.  Broadly speaking, if there is a biomass plant and fossil fuel plant both running unabated the same benefit can be achieved by capturing a tonne of CO2 from either.

Indeed there may be advantages to putting CCS on a conventional plant rather than biomass plant.  It may be technically more tractable.  Furthermore, CCS require a lot of energy to capture the CO2 and then to compress and pump it for permanent storage.  Biomass is likely to be supply constrained (again, this is an issue that requires a post in itself), so using biomass rather than fossil fuels to provide this energy may limit other applications.  Only when there are no fossil fuel plants from which to capture CO2 does biomass plant become unambiguously a priority for CCS.  This is clearly some way off.

Furthermore biomass with CCS for electricity generation may not be the best use of bioenergy.  Converting sunlight to bioenergy then turning that into electricity is a very inefficient process.  Typically only 1-2% of the sunlight falling on an area of cropland ends up as useful chemical energy in the form of biofuels.  There are various reasons for this, not least of which is that photosynthesis is a highly inefficient process.  Burning biomass to make electricity adds a further layer of inefficiency, with only perhaps a third or less of the energy in the biomass turned into electricity.  Sunlight therefore gets converted to electricity with an efficiency of perhaps 0.5%.  This compares with around 15- 20% for solar cells, implying that scarce land is often likely to be best used for solar PV.  (The calculation is closer if solar PV is used to create storable energy e.g. in the form of hydrogen).   For similar reasons the use of biofuels rather than electricity in transport is inefficient, in part because internal combustion engines are less efficient than electric motors.

Limited available biomass may be better used for those applications where it is the only available lower carbon energy source, notably in aviation and (likely) heavy trucks, or for other applications such as district heating with CCS, where the ability to store energy seasonally is especially valuable.

At the very least, detailed system modelling will be required to determine the optimal use of biomass.  Suggesting that BECCS should have a major role to play simply because in isolation it has negative emissions may lead to suboptimal choices.

Direct Air Capture (DAC)

Direct Air Capture (DAC), where carbon dioxide is chemically absorbed from the atmosphere and permanently sequestered, can also reduce the stock of CO2 in the atmosphere.  However the typical concentration of CO2 in a flue gas of a power plant or industrial plant is several percent, about a hundred times as great as the concentration of 0.04% (400 ppm) found in the atmosphere.  This makes the capture much easier.  Furthermore, millions of tonnes can be captured and piped from a single compact site using CCS, generating economies of scale on transport and storage.  In contrast DAC technology tends to be more diffuse.  These considerations imply that CCS from power plants and industrial facilities is always likely to be preferable to direct air capture until almost all the opportunities for CCS have been implemented, which again is a very long way off.

Uncertainties and optionality

There are many uncertainties around negative emissions technologies, including the availability of biomass, cost, and the feasibility of reducing emissions in other sectors.  For these reasons developing optionality remains valuable, and research to continue to develop these options, including early trial deployment, is needed, as others have argued[i].

One of the best ways of developing optionality is to deploy CCS at scale on fossil fuel plants.  This will reduce the costs and enable the development of improved technologies through learning on projects.  It will also help build infrastructure which can in turn benefit  BECCS.  This needs to run in parallel with ensuring that the lifecycle emissions from the bioenergy production chain are reduced and biodiversity is safeguarded.

Negative emissions technologies may well have a role to play in the latter part of the century.  But they seem likely to make more sense when the economy is already largely decarbonised.  In the meantime deployment of CCS, whether on industrial facilities or power plants, needs to be a much greater priority.

Adam Whitmore – 21st March 2016

[i] Investing in negative emissions, Guy Lomax,  Timothy M. Lenton,  Adepeju Adeosun and Mark Workman, Nature Climate Change 5, 498–500 (2015)  http://www.nature.com/nclimate/journal/v5/n6/full/nclimate2627.html?WT.ec_id=NCLIMATE-201506