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Green Plan Ireland and the Paris Agreement: A cumulative CO₂ assessment

posted Jul 16, 2018, 5:16 AM by Paul Price   [ updated Aug 15, 2018, 3:31 AM by Barry McMullin ]

For the IE-NETS project we have been examining a number of user-friendly and/or open source energy system models that may be useful in informing policy in aligning climate action with the Paris Agreement and in indicating the possible need for carbon dioxide removal and a timeline for investing in negative emissions technologies to accomplish this.

One such model is EnergyPLAN, developed and maintained by Aalborg University in Denmark, with which users can start by setting up a reference model matching the energy supply and demand infrastructure and parameters of a current energy system. From this, users can then develop a plausible sequence of scenario steps for a low carbon transition. The EnergyPLAN model focuses on achieving a 100% renewables energy system so the modelling of fossil fuel, carbon capture and storage or nuclear power is relatively basic, but the modelling of technologies such as combined heat and power, district heating, energy storage and power-to-fuel is more detailed.

Though not open source, EnergyPLAN is well documented, easy to use and runs quickly in a Microsoft Windows operating system. Building the reference model from available data takes time but once completed alternative scenario options can rapidly be explored. Hourly balance of the energy system enables a reasonably fine grained look at a scenarios involving high capacity and grid penetration of variable renewables combined with modelling of synthetic liquid or gaseous fuel production to use excess energy production and store it for use in periods when there is insufficient wind or solar.

David Connolly's Green Plan Ireland

Using the EnergyPLAN energy system simulation model, while at Aalborg David Connolly (now CEO of the Irish Wind Energy Association) proposed Green Plan Ireland, a series of six steps in demand management and renewable energy development, by which Ireland could potentially transition its energy system to being based on 100% renewables energy supply  (Connolly and Mathiesen, 2014). You can see the paper, a video presentation and all data via links at the Green Plan Ireland webpage. For each of these steps the EnergyPLAN output data gives a net value for CO2 emissions. The Aalborg modelling does assume that all bioenergy is “carbon neutral” – as per current EU methodology and policy, though at odds with much science – but does aim to limit bioenergy use.

In this blogpost we very simplistically imagine fully accomplishing one of these steps every five years up to 2050, draw a straight line between of these annual emissions levels and then add up the total CO2 emissions of this imagined Green Plan Ireland emission pathway to 2050. We then compare this CO2 commitment to the possible Paris-aligned CO2 quota for Ireland as estimated in previous IE-NETS work. This is only an exploratory assessment, nonetheless it does give a blog-level exploratory view that can set some basic context for the timeline of low carbon transition planning.

In outline, Green Plan Ireland begins with Step 1, a reference model matching the projected Irish energy system as of 2020, followed by a transition of energy supply to 100% renewables by 2050 via the following six steps:

  • Step 1. Reference model

  • Step 2. District heating (2020)

  • Step 3. Heat pumps for building heat

  • Step 4. Electricity grid regulation

  • Step 5. Demand side management (DSM) and electric vehicles & (EVs)

  • Step 6. Synthetic methanol/DME

  • Step 7. Synthetic methane production

For the purpose of this modelling energy demand is assumed to stay constant in terms of total and sectoral breakdown. The last two steps in particular require large scale expansion of wind energy, especially offshore, so that excess capacity can enable energy storage via synthesised chemical energy storage in electrofuels: synthetic liquid fuels (methanol and/or  dimethyl either) and synthetic gaseous fuel (methane). Running EnergyPLAN for each scenario step gives a value for nett annual CO2 emissions for each one. Using an import/export‐corrected fuel account, the model additionally calculates a value for “corrected CO2 emissions”. At Step 7 in the Green Plan the EnergyPlan modelling of the Irish energy system yields marginally negative CO2 emissions, at least on a corrected basis (and assessing bioenergy as CO2 neutral).

A Simple Green Plan Emission Path Scenario

In the chart below an emission scenario imagines fully accomplishing each one of the six steps from 2020 to 2050, assuming that 2015 to 2020 emissions are flat at the Step 1 Level of just over 38 MtCO2 per year from the energy system (although in fact we know they have increased in 2016). Drawing a straight line between each of these annual emissions way points then gives us an imagined emissions pathway to 2050. We will come back to the dashed green pathway that is also shown.

As shown in the next chart below, we can then sum the CO2 emissions starting in 2015 and adding on each year of emissions (from the values in the annual chart above) to get a cumulative total pathway to 2050. This is important because cumulative CO2 emissions are the predominant driver of long-term global warming and climate change, and therefore provide a gauge of Ireland's climate action policy effectiveness. For the scenario shown the annual emissions from 2015 to 2050, add up to cumulative CO2 calculated as just over 1000 MtCO2 (or about 900 MtCO2 after correcting for import/export).

In IE-NETs we have presented previous work based on the current scientific estimates of  the remaining, nett global carbon budget range of CO2 emissions from 2015 onwards, necessary to align global action with the Paris Agreement temperature target of “well below 2ºC”. For Ireland, a population-based share of the mid-point of this global carbon budget is only 586 MtCO2. Though representing some attempt at equity, this “equal per capita” allocation of the budget is overly generous: it cannot be said to be properly “equitable” (as the Paris Agreement demands) because it does not account for responsibility for past emissions, current high emissions or capacity to act. In any case, allowing for Ireland’s ongoing nett land use CO2 emissions reduces the quota share for energy system emissions to about 534 MtCO2, which is shown as a dotted green line in the chart below. (Note: Glynn et al. 2018 uses a different global carbon budget basis and arrives at a somewhat higher 766 MtCO2 quota for Ireland using the same type of allocation.) The green dashed "Even Effort Path" line in both charts shows the effect of a constant fractional reduction rate pathway of -7.1% per year, starting at the 2015 level - which would (asymptotically) use exactly the estimated cumulative quota.

Cumulative CO2 Implications for Paris-Aligned Climate Action Policy

This very simple assessment sets the Green Plan Ireland steps defined by Connolly and Mathiesen into a sequential, 5-yearly series to 2050. The charts indicate that this apparently extremely ambitious plan, which does achieve very deep emissions rate reduction by the final stage in 2050, still does not limit Ireland’s cumulative CO2 emissions to even a minimally equitable Paris-aligned carbon quota.

Cumulative emissions as shown go above the quota limit before 2030 and go on to exceed the quota by a total of 350 to 400 MtCO2. This is similar to the scale of maximum technical potential for negative CO2 emissions to 2100 estimated earlier in the IE-NETS project. Therefore, following such a pathway would commit Ireland to achieving these very high levels of negative emissions, using what are currently speculative technologies in terms of both cost and performance with large implications for land use area needed, for example to produce energy crops for bioenergy with carbon capture and storage (BECCS). Even if faster or other mitigation measures are applied it seems likely that some level of negative emissions capacity may be needed, requiring investment in at least some carbon capture and storage.  This CCS capacity might need to be prioritised for bioenergy rather than abating interim fossil fuel emissions (the so-called “fossil fuel bridge” model) so that negative emissions can be realised.

Of course, it is possible that the Green Plan steps could be planned to overlap in time and begin much earlier in terms of investment and achievement so that the decarbonisation pathway followed in Ireland’s ‘low carbon transition’ is far closer to the required target path. Critically, it is the final two steps that have the largest effect on total energy system emission reductions. This suggests that early investment in development in synthetic fuel R&D and capacity building, including offshore wind turbines might need to be a critical focus for mitigation planning in order to incorporate these key changes as early as possible in the energy system transformation, thus yielding the maximum impact on cumulative CO2 emissions.

It is evident from the charts that early and deep mitigation effort are needed to limit the large, subtractions from the carbon quota due to ongoing high emissions. The Green Plan only looks at energy supply to meet current sectoral demands, so near-term measures that achieve real cuts in absolute demand would greatly assist in mitigation. Energy efficiency may help here, but only if carbon pricing or supply regulation is sufficient to eliminate rebound effects that encourage spending of cost savings. Immediate phase-out of the most carbon intensive fossil fuels in electricity production, peat and coal, would provide an important early benefit.

To be “cost effective”, as demanded by Ireland’s Climate Act, mitigation action must add up to meeting a science-based target, in this case a Paris-aligned carbon quota, with a high degree of certainty. By definition, not meeting the target is not cost effective, so the choice is then between options that meet the target at least cost. Existing investment guidance is often based on near-term carbon prices which do not reflect the climate impacts if the science-based targets are exceeded; and this may preclude investment in what are ultimately likely to be the most important technologies – possibly including failing to invest early in synthetic fuel production as indicated above for the Green Plan. On the demand side, the option to reduce existing high emitting activities in favour of potentially economic lower emitting activities can too easily be omitted from mitigation studies that may be overly influenced by the present economic mix. Research shows that early, substantial investment is required for the those areas thought most difficult to mitigate. Likewise, the possibility of large new energy demands, such as the promotion of new data centres, may need to be considered carefully relative to decarbonisation pathways.

Ongoing work in the IE-NETS project is further examining and modelling the required scale and speed of emission reductions to align Ireland’s climate action with the Paris Agreement, including possible tacit commitment to achieving some level of negative emissions. The simple scenario sketched above echoes the overwhelming consensus of international climate mitigation research: any and all delay in actually achieving deep decarbonisation quickly risks likely failure to meet Ireland’s Paris commitment. As the Sustainable Energy Authority of Ireland state in their recent submission to the Oireachtas (Irish Parliament) Committee on Communications, Climate Action and Environment:

The longer the delay of annual total (net) emissions reductions (in the order of 10% per annum) the more challenging and costly future decarbonisations become. Modelling scenarios will need to be updated to ensure they are based on achieved levels of decarbonisation in each accounting period, and in the event of delayed mitigation will indicate a shrinking time horizon for fossil fuel use, and the need for costlier solutions such as negative emissions technologies (e.g. bioenergy CCS) in the future.

Looking forward to the International Conference on Negative CO₂ (and #BeyondFlying)...

posted May 18, 2018, 12:48 AM by Barry McMullin   [ updated May 18, 2018, 12:48 AM by Paul Price ]

The first International Conference on Negative CO₂ Emissions will take place on May 24-26 2018 in Gothenburg, Sweden. As part of the ie-nets project team working on a (small) project to assess the potential for negative CO₂ emissions in Ireland, I’m delighted that we have had two abstracts accepted for presentation, and I’m very much looking forward to meeting and engaging with the emerging international community of researchers working on this critically important topic.

And yet: I’m also torn. Dublin, where I live, and Gothenburg are 1240 km apart. My return flight would represent a combined GHG emission commitment of the order of 250-500 kgCOe. Trivial in a global sense: but if academic “experts” on climate action appear unwilling to urgently reduce their own emissions, does that not grievously undermine any message we might have for wider society?

Now you may say I’m a dreamer ... but I’m not the only one! The Tyndall Center for Climate Change Research has published a very useful working paper, Towards a culture of low-carbon research for the 21st Century and there already exists a public petition calling on academic institutions to address this issue, called Flying Less: Reducing Academia's Carbon Footprint.

Which all brings me to a “modest proposal”. I do hope the Gothenburg event is the first in a series of such conferences: but, I also hope that, as a new, emerging, research community we might consider, from the start, radical ways to reduce the environmental impact of everything we hope to do. I would point, for example, at the Nearly Carbon-Neutral model that can deliver a highly effective international conferencing experience but without the burden of large scale travel. In the meantime: I am still very much looking forward to Gothenburg, but for myself, I’ll be choosing not to fly, but to travel by ferry and train instead. It will cost rather more and take a little longer (four extra days overall!), and of course, the carbon “saving” will be no more than symbolic. But I hope that sometimes symbols may matter more than they appear. And if you are also travelling to Gothenburg, do please look out for me there and let me know what your own thoughts are on a life Beyond Flying!

Barry McMullin, Dublin, Ireland
Reach me at: barry.mcmullin@dcu.ie

Ireland’s domestic climate policy needs updating to include ten million tonnes of untargeted emissions

posted Apr 16, 2018, 2:03 PM by Paul Price   [ updated Apr 17, 2018, 12:15 AM ]

The Environmental Protection Agency, the EPA, provides Ireland’s most recent complete emission inventory data, up to 2015, published 2017 [pdf]. Comparing inventory emissions with Ireland’s core climate policy it becomes clear that about 10 million tonnes CO2e of Ireland’s emissions (on a GWP-100 equivalence basis) are not currently targeted by national policy, even though these emissions are accounted in EU targets – and do, of course, physically affect Earth’s climate system by adding to global warming. These ‘missing emissions’ are primarily from manufacturing, industry, waste and also ‘F-gases’ (used in refrigeration and air conditioning). In this blogpost, we discuss this issue and some possible implications for climate policy and policy analysis.

Ireland’s current climate action policy, most fully stated in the 2017 National Mitigation Plan, continues to be based on a policy statement made in 2014 called the National Policy Position (NPP). This states that:

“The low-carbon roadmapping process will be guided by a long-term vision of low-carbon transition based on –

• an aggregate reduction in carbon dioxide (CO2) emissions of at least 80% (compared to 1990 levels) by 2050 across the electricity generation, built environment and transport sectors; and

• in parallel, an approach to carbon neutrality in the agriculture and land-use sector, including forestry, which does not compromise capacity for sustainable food production.”

Separately from, and pre-dating, this national policy, Irish emissions are also subject to binding EU emission reduction policies, where emissions are divided between: the EU’s Emission Trading Scheme, the ETS (from large industrial sources, such as power stations, industrial heat use and cement production); and non-ETS emissions, which are limited according to the Effort Sharing Decision whereby each nation is assigned an emissions pathway (allocated by negotiation according to different assessed national mitigation potential).  For the linear, national non-ETS emission pathways each Member State is legally bound to stay within their corresponding allocated total of non-ETS emissions for periods up to 2020, and soon, under the forthcoming EU Climate Action Regulation, to 2030.

However, rather than reflecting this ETS vs. non-ETS distinction, the NPP does not mention the separation at all. Indeed, it mixes them together – the electricity generation facilities are covered by the ETS, whereas the built environment, transport, and agriculture and land-use sectors are all within the non-ETS sector. Built Environment includes mainly heating-associated emissions in the Public and Commercial Services, and Residential sectors.

Logically, as the NPP takes this collective approach to territorial greenhouse gas emissions, ignoring the ETS/non-ETS distinction, we can ask: Are all GHGs therefore included in the key NPP statement quoted above?  Obviously they are not, some major sectors are omitted from mention altogether: there is no targeting of reductions in Manufacturing Combustion, Industrial Processes, F-gases, Waste sectors, or in Energy Industries other than electricity, including petroleum refining, solid fuel manufacture and fugitive emissions. These ‘missing emissions’ amount to a considerable 10.3 MtCO2e or 17% of 2016 total Irish CO2e emissions. See the Excel file here which includes lines below the main tables adding up these missing emissions, for example in the Provisional Summary 1990-2016 sheet detailing total national emissions.  In terms of EU targets, the missing emissions add up to 5.8 MtCO2e or 33% of Ireland's ETS emissions, and 3.6  MtCO2e or 8% of non-ETS emissions.

Even though these territorial emissions are ultimately covered by the EU targets it is striking that there is no mention at all of these key sectors in the NPP.  These omissions are surprising as the NPP is specifically framed in the context of the aligning action with the UNFCCC objectives (now concretely stated in the Paris Agreement) and the associated European Union objective of reducing greenhouse gas emissions by 80-95% by 2050 compared to 1990.  The latter EU 2050 Roadmap assumes EU-wide average reductions of ~85% in Industry and ~74% in non-CO2 (especially Waste and F-Gases) emissions by 2050, yet these sectors are not given a target or included at all in the NPP. It is very difficult to see how deep, economy-wide and sectoral emissions reductions can be achieved if significant sectors are excluded from the explicitly stated targets in Ireland’s climate action policies.

This omission of major sectors from the NPP and the lack of clarity in aligning the policy position with the EU targets undoubtedly has the potential to increase confusion in Ireland’s carbon governance capable of achieving a low carbon transition, especially relative to meeting the separate ETS and non-ETS targets. Sectors outside the NPP definitions could possibly even be incentivised to grow – contrary to the need for decarbonisation across all sectors – simply because their emissions are not readily apparent to policy analysis that is primarily based on the NPP statement that fails to target them.

It should also be of serious concern if some sectors of emissions are not fully included in policy analyses and projections, given that policies will nonetheless need to achieve the EU targets that do include these emissions. Several policy analyses by agencies and researchers released since the NPP are notable for charting the NPP's EGBET emissions yet failing to chart pathways for all CO2 and non-CO2 emissions, thereby overlooking emissions from the omitted sectors. Even if current national policy does not target them, objective policy analysis and projections by agencies, researchers and NGOs needs to assess the trajectory of all of Ireland’s greenhouse emissions relative to international climate commitments.

To avoid the evident risk of overlooking or downplaying the need for climate action by the unnamed sectors, an obvious climate policy recommendation would be to redraft the core NPP statement for the NMP as soon as possible to target all territorial emissions and sectors. (Ideally, the NPP would also state a cumulative CO2 quota in aligned with the Paris Agreement, replacing the currently stated 2050 target, which could result in high total emissions depending on the pathway taken.) As research makes very clear, in the context of the Paris Agreement and the EU objectives, all sectors will need to target substantial and sustained emission reductions.

Updating the National Mitigation Plan to include the missing emissions noted here, by targeting all sectors explicitly, would increase the coherence, effectiveness and ambition of Ireland’s climate action.

Upcoming International Conference on Negative CO2 Emissions (and a "modest proposal"...)

posted Apr 12, 2018, 6:06 AM by Barry McMullin   [ updated Apr 12, 2018, 6:28 AM by Paul Price ]

The IE-NETs project will be represented at the upcoming International Conference on Negative CO2 Emissions, where we will give two short presentations on summary results from our recently completed Post-Paris Literature Review of Negative Emissions Technology, and Potential for Ireland. We're very much looking forward to meeting and engaging with the emerging community of NETs/CDR researchers at this first international conference dedicated to these topics.

That said ... we're also keenly aware of the environmental (and especially climate) impact of our own activities. With that in mind, we have just offered a "modest suggestion" to the conference organisers, which we share here in case it is of wider interest. Even if the suggestion proves too late for formal discussion at Gothenburg, we would certainly appreciate any reactions or comments from visitors to the IE-NETs blog. Do feel free to email us at: ienets@dcu.ie

From barry.mcmullin@dcu.ie Thu Apr 12 12:54:59 2018
Date: Thu, 12 Apr 2018 12:54:26 +0100 (IST)
From: Barry McMullin 
To: Int. Conf. on Negative CO2 Emissions 2018 
Cc: Barry McMullin 
Subject: Planning future NETs/CDR conferences: a modest suggestion?

Dear conference organisers -

This is a very late suggestion, so I will completely understand if it is not feasible... but I am guessing that there may be some slot during the conference where there will be discussion of possible future conferences in this “series”? If that is the case, I would like to suggest that there might be some specific discussion of whether to migrate wholly, or at least partially, to a “nearly carbon neutral” (NCN) conferencing model, as described here, for example:

“A Nearly Carbon-Neutral Conference Model:White Paper/Practical Guide”

This suggestion of course reflects the very active discussion in the wider climate research community in relation to the interaction between our own academic culture and norms and wider societal perceptions and expectations, as highlighted for example here:

“Towards a culture of low-carbon research for the 21st Century”[Tyndall Centre for Climate Change Research]

and here:

“Flying Less: Reducing Academia's Carbon Footprint” [A petition addressed to “Universities and Professional Associations”]

If this suggestion is of interest, obviously I would be very happy to help facilitate or support the discussion in any way that might be useful or appropriate.

Kind regards - Barry.

PS: For what it is worth - I will be using surface travel only (ferry/train) to get from Dublin to Gothenburg. This will, of course, have negligible material impact on the emissions associated with the conference: but it is a symbolic act of solidarity with other “low carbon” academics, that seems important to me personally, at least...

Professor Barry McMullin,
School of Electronic Engineering
Dublin City University
   phone: +353-1-700-5432
   web: http://www.eeng.dcu.ie/~mcmullin/
   skype: barrymcmullin-dcu.ie

IE-NETs is hiring! Post-doc position, School of Natural Sciences, Trinity College Dublin

posted Apr 12, 2018, 1:42 AM by Barry McMullin   [ updated Apr 12, 2018, 1:56 AM by Paul Price ]

Advert text:

"This is a 9-month post-doctoral position on an EPA funded project entitled ‘Investigating the Potential for Negative Emissions Technologies (NETs) in Ireland’. The work involves the use of crop growth modelling to create a productivity map of the energy crops, Miscanthus and willow in Ireland and using Life Cycle Assessment of greenhouse gas emissions and techno-economic analysis of bioenergy production with a focus on the potential for BECCS (Bioenergy with Carbon Capture and Storage). The work will be undertaken in The Botany Department, School of Natural Sciences, Trinity College Dublin under the supervision of Professor Mike Jones. For further details contact mike.jones@tcd.ie. Applications including a CV should also be sent to mike.jones@tcd.ie"

Climate action or carbon debt?

posted Mar 22, 2018, 9:38 AM by Paul Price   [ updated Mar 22, 2018, 9:42 AM ]

How quickly are different regions and nations committing to responsibility for substantial negative emissions? Or, to tacit mitigation failure?

The Paris Agreement commits the signatory Parties (essentially all sovereign nations of the world) to aligning their actions with,

“[h]olding the increase in the global average temperature to well below 2°C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5°C above pre-industrial levels, recognizing that this would significantly reduce the risks and impacts of climate change”    Article 2, Paris Agreement

Thanks to the strong climate science showing a direct, linear relation between cumulative total human-caused emissions of carbon dioxide (CO2) and resultant long-term global warming, a global carbon budget (GCB) range can be estimated for any given probability of limiting to any given threshold of warming. Using a 66% probability of avoiding 2ºC, the IPCC give a post-2011 GCB range of 750 to 1400 GtCO2 (where Gt means gigatonnes or billions of tonnes). Adjusting this for emissions up to the end of 2015, Rogelj et al. (2016) suggest a remaining post-2015 (i.e., post-Paris Agreement) budget of 590 to 1240 GtCO2, with a mid-point of 915 GtCO2. Of course, a “lay”/common-sense interpretation of “well below 2ºC” (surely at least better than 66% probability of staying below, say, 1.75ºC?) or any “efforts” at all to respect the lower limit of 1.5ºC (surely at least 50% probability?) would yield significantly smaller ranges for the GCB.

A somewhat simplistic, but still informative starting point to compare the current emissions of regions and nations is on the basis of per capita CO2 emissions relative to per capita CO2 quotas, where quota means some allocated share of the remaining global carbon budget.  Simply, dividing the Rogelj et al. range by the 2015 global population of 7.4 billion people, gives a globally averaged range of remaining post-2015 per capita quota of 80 to 169 tCO2, with a mid-point of 124 tCO2.  

Although this is an ‘equal per capita’ GCB division, derived from regional or national population share in 2015, it’s important to be very clear that this sharing formula is not “on the basis of equity” (Article 4, Paris Agreement) because it ignores very significant differences in: historic responsibility (based on past emissions), technical and economic capacity to undertake mitigation measures, vulnerability to climate impacts, and the wider objectives of the sustainable development goals (SDGs). Taking such equity considerations adequately into account would greatly diminish the quotas assigned to the wealthy, developed nations (indeed, would arguably put at least some of these nations already in a situation of quota deficit or global “CO2 debt”). Nonetheless, this equal per capita cumulative emissions (EPCCE) basis might provide us with at least an initial “rough and ready” baseline to compare the “good faith” commitments with the actual efforts of regions and nations to deliver on the temperature goals of the Paris Agreement.

For this blogpost analysis, let’s look at how quickly the EPCCE quotas would be exhausted (from 2015), assuming that every region or nation simply ‘flatlined’ their existing CO2 emission rate at 2016 levels. Globally, for territorial fossil fuel and cement emissions, this ranges from very high emitters such as the USA with 16.5 tCO2 per capita per year and high emitters such as Ireland with 8.5 tCO2 per capita per year, to very low emitters such as Bangladesh with only 0.5 tCO2 per capita per year. Let’s assume that current global land use emissions, about 5 GtCO2 per year (nett, allowing for land use carbon sinks) are also allocated per capita, adding about 0.7 tCO2 per capita per year to each nation’s per capita CO2 emissions. (This is, of course,  another very simplistic assumption – that, for example, more than doubles the emissions assigned to Bangladesh but only adds 4% to the USA per capita figure.)

For the midpoint global carbon budget of Rogelj et al., the chart below therefore shows the resulting (straight line) annual depletion of EPCCE for selected regions and nations: starting all with an equal EPCCE and, thereafter, for each region or nation, just subtracting the 2016 value of estimated total CO2 emissions for each subsequent year, giving the remaining per capita quota for each yer..

For reference, the curved, dashed black “global decarbonisation” line shows how global EPCCE would decline under a constant year-on-year fractional emission reduction rate (exponential emission rate decline), chosen in such as way as to extend the remaining global carbon budget for the maximum time i.e., the “softest possible landing trajectory” for global decarbonisation (albeit, already very difficult to achieve at this point…). As of 2015, from current global emissions of about 41 GtCO2, this would require annual emission rate reductions of 4.5% per year. The pink area below zero indicates carbon debt and dotted lines for the nations or regions indicates negative quotas, where the available EPCCE would have been exhausted, implying those nations would, from that point on, be accumulating a growing responsibility for implementing (or paying someone else to implement) so-called “negative emissions” or “carbon dioxide removal”. For Ireland, this would become the case before 2030 in this analysis.

Even using assumptions heavily biased in favour of developed nations/members of the OECD and/or EU28  (i.e., the weakest conceivable interpretation of the Paris temperature goals, and of the Paris commitments to reflect “common but differentiated responsibilities and respective capabilities, in the light of different national circumstances”), this chart graphically shows how developed nations, or even a rapidly developing nation like China, are all very quickly exhausting their Paris Agreement ‘CO2 credit’. Without urgent action they are heading toward deep (likely irrecoverable) CO2 debt relative to the Paris target. Aligning their actions with “well below 2ºC” without such tacit reliance on speculative future “negative emissions” requires radical mitigation measures to reduce from currently high, whole economy CO2 emissions (at an annual reduction rate, sustained indefinitely, of at least the global requirement of 4.5%/yr). In addition, if serious about Paris-level ambition, then precautionary commitment to careful (limited) anthropogenic enhancement of  CO2 removals from the atmosphere will very likely be necessary.

Meanwhile, low emitting, less developed nations like Bangladesh, are only using up their carbon quotas very slowly – despite often being the most exposed to the climate change impacts resulting from the fossil fueled development and consumption elsewhere.

Unfortunately, to date, emission projections and Paris mitigation pledges (Nationally Determined Contributions) are in fact mostly in the range of merely ‘flatlining’ near-term emissions rates, so the chart is a very concerning reflection of the current situation in global (developed world) climate policy.

Indeed, for Ireland, the EPA’s projections to 2035 indicate that annual CO2 emission rates will actually continue, not merely to “flatline” but to increase even “with additional measures” – in other words an even worse outlook for very early, rapid, and deep entry into carbon debt than the chart shows. We might call this “carbon bankruptcy”, except, of course, that the climate system is not a bank, and has no mechanism to offer “debt restructuring”. Rather, there will be only harsh, perhaps unbearable, consequences, though these will likely impact “innocent bystanders” in poorer and more vulnerable nations first. As the chart makes very clear, ‘flatlining’ (or, much worse, increasing) CO2 emissions is not an option for any nation if the aim is to restrict warming in any way equitably. Nations with high emissions will need to cut much faster and deeper to leave any ‘CO2  emission space’ for countries with lesser responsibility and capacity.

Rich nations are committing to achieving large "negative emissions", or are they "choosing failure"?

Looking at this chart we can ask: Is a tacit commitment being made by those going into carbon debt to achieving large negative emissions (removals of CO2 from the atmosphere)?  Or, are they simply “choosing to fail” – to quietly renege, in practice, on the requirements of the Paris Agreement?  In the absence of sufficient mitigation, It might easily be assumed to be the latter, unless sufficient investment to support real achievement of balancing negative emissions. This would sadly vindicate the blunt assessment of eminent climate scientist James Hansen, that the Paris Agreement is a mere “precatory” instrument – wishful thinking, dressed up in diplomatic and legal language.

Flatlining Ireland’s current emissions and aligning climate action with Paris would imply a commitment to total emissions of about 1540 MtCO2 just up to 2050 – and much more beyond. As Ireland’s post-2015, remaining national quota is only about 600 MtCO2 (on the generous 2015 EPCCE basis), flatlining implies achieving carbon dioxide removal of close to 940 MtCO2 by 2050. This is an enormous and likely unfeasible quantity to store, the equivalent of over 20 years of current emissions. It would necessitate the urgent development now, and use within a decade, of carbon capture from bioenergy (BECCS) and direct air capture (DACCS), then piping and injection to storage deep underground.  As a guide, the almost-exhausted Kinsale Gas Field is thought to have a capacity for “easy” (low-pressure) CO2 storage of only about 100 Mt.

Compared to the costs of CO2 storage and the risk that negative emission technology will not deliver at scale, aiming to deliver actual whole-economy, gross emission reductions now and in the near-term, at rates hitherto thought ‘unfeasible’, combined with some commitment to modest achievement or enhancement of negative emissions may well prove more ‘cost effective’ (see previous post). Even if these measures are expensive or reduce aggregate economic activities they will likely be the cheapest course, if indeed we are serious about aligning climate mitigation efforts with the Paris Agreement. The overwhelming consensus of mitigation literature makes clear that any and all delay in peaking and very rapidly decarbonising rapidly increases the costs (and human impacts) of meeting the temperature targets.

As agreed in Paris, for all developed nations, early and deep climate action is critical to mitigation success. Our chart above clearly illustrates this difficult reality and the urgency of coordinated action now required to observe the Paris temperature limits. Are choosing to fail? Or, are we collectively ready to discuss this reality frankly and honestly?


Rogelj, J., Schaeffer, M., Friedlingstein, P., Gillett, N.P., van Vuuren, D.P., Riahi, K., Allen, M., Knutti, R., (2016). Differences between carbon budget estimates unravelled. Nature Clim. Change 6, 245–252. https://doi.org/10.1038/nclimate2868

Where is the low carbon [sic] energy vision Ireland needs to mitigate climate change?

posted Mar 13, 2018, 3:44 AM by Barry McMullin   [ updated Mar 13, 2018, 4:17 AM by Paul Price ]

The 2018 Spring Energy Policy Seminar of the Nuclear Free Local Authorities (NFLA) All Ireland Forum took place on Friday 9th March in Omagh, Northern Ireland. The NFLA "... lobbies for improvements in the provision of renewable energy across Ireland, the encouraging of Council-led decentralised energy schemes and provides information on the risks to Ireland from the UK's nuclear energy and waste programme, as well as promoting the support of moves for international multilateral nuclear disarmament. The All-Ireland Forum is part of the UK and Ireland NFLA organisation which has four national Forums and itsheadquarters in Manchester."

I was invited to give a presentation at the event, with suggested title "Where is the low carbon energy vision Ireland needs to mitigate climate change? And how can it be delivered?" I explained to the organisers that nuclear energy is not prima facie excluded from the energy system scenarios I explore. Nonetheless, they kindly gave me the opportunity to present without any restriction, which I was very pleased to take up.

The presentation slides, including embedded links to more detailed resources are now available for download. The seminar itself was not recorded. However, I have made a screencast version of my own presentation, which can be viewed on the ie-nets youtube channel:

YouTube Video

 While the slides are exactly the same as the original live presentation, I took the opportunity to elaborate on a number of points, and this version is a good deal longer (at just over one hour) than the original c. 25 minute version presented in Omagh.

As I mention in the presentation, virtually every proposition I make is a simplification of some sort and could certainly be contested. I would welcome any comments or questions. I can be reached at: barry.mcmullin@dcu.ie 

ie-nets team contributes to event by the Royal Irish Academy for the recent EASAC report on negative emissions

posted Mar 8, 2018, 7:02 AM by Alwynne Hanna McGeever   [ updated Mar 9, 2018, 2:04 AM by Paul Price ]

The European Academies Science Advisory Council (EASAC) provide independent science advise for EU policymakers, based on the expertise of leading scientists in national academies from EU member states, Norway and Switzerland. On February 1st, EASAC released a report entitled ‘Negative emission technologies, What role in meeting Paris Agreement targets?’. The report was written by a group of senior scientists in the area, one of which was ie-nets team member, Prof. Mike Jones. 

The report found that Negative Emission Technologies (NETs) had ‘limited realistic potential’ and are unlikely to be delivered at the scale envisioned by the Intergovernmental Panel on Climate Change (IPCC)’s scenarios. This has significant implications for the feasibility for Europe achieving nett emission reductions aligned with the commitments to the Paris agreement and places further urgency on the need for immediate, significant emissions reductions. The findings of the EASAC report (available to download here) support the conclusions of a recent deliverable by the ie-nets research team of a literature review on the potential for NETs in Ireland (available here). We draw similar conclusions that Ireland cannot depend upon future availability of NETs to meet Paris aligned emission targets, and must continue to prioritize reducing national annual emissions.

As part of the Royal Irish Academy (RIA)’s aim to bring academia, industry and government together to address mutual interests, and as a member academy of EASAC, the RIA provided a briefing breakfast event for the EASAC report on Monday, February 26th.The event was well attended by a diverse group of stakeholders from academy, industry, NGOs and government. The event took the format of a brief presentation, followed by an open discussion. ie-nets Co-Principal Investigator, Prof. Mike Jones, delivered the presentation component, summarizing the main findings of the EASAC report and communicating its implications for Ireland. In his presentation Prof. Jones highlighted some of the key uncertainties around different NETs options. Taking the example of Bioenergy with Carbon Capture and Storage (BECCS), he discussed issues such as the land area competition and greenhouse gas emissions associated with producing bioenergy crops (fertilizers, transport, etc.) and demonstrated how challenges such as these might prevent a NETs options to achieving truly nett negative emissions. He also applied the report to an Irish context, presenting options to assess the potential capacity of different NETs options in Ireland. After the presentation, attendees discussed the report in an Irish context, raising points about the feasibility, capacity and limits of different NET options for Ireland. There was particular emphasis in the discussion the on the feasibility and capacity of carbon capture and storage off the Irish coast.

As part of this event, ie-nets team members contributed to a briefing paper for the RIA and a blog post, available on the RIA website here.


How to spend the dwindling global carbon “budget”? (and Ireland’s dwindling carbon quota share of it)

posted Jan 31, 2018, 2:00 AM by Paul Price   [ updated Jul 16, 2018, 6:19 AM ]

Viable pathways to "well below 2ºC"?

Due to continued high global greenhouse gas emissions it is becoming very difficult to show viable mitigation pathways to stay "well below 2ºC" of global warming without resorting to some serious commitment to carbon dioxide removal (CDR) from the atmosphere using negative emissions technologies (NETs). This would, of course, be in addition to the imperative necessity of achieving sustained reductions of gross (“positive”) emissions.

Allowing negative emissions in mitigation planning theoretically enables a slightly more gradual reduction in fossil fuel use but comes at a cost of added risks, including the risk that negative emissions technologies may fail to deliver at scale, as discussed in detail by Larkin et al. 2017 (open access).

The Paris Agreement temperature targets, currently agreed to by all nations, mandate limiting global average surface temperature rise to well below 2ºC, and ideally to no more than 1.5ºC above pre-industrial. Scientifically, the remaining carbon budgets for these two targets are much the same (see this post by Glen Peters) and though the uncertainty in the likely budget range is large the need for action is clear. In terms of near-term mitigation risk though, the key danger results from delaying sufficient early mitigation action, simply because every year of high emissions (CO₂ in particular) is reducing the available finite remaining global carbon (CO₂) budget to limit global warming to the Paris targets.

If negative CO₂ emissions capability is assumed (in policy and planning) then a key question – in addition to the risks and feasibility of the technologies – is whether CO₂ concentration in the atmosphere is allowed to temporarily overshoot the level compatible with the temperature limits, and for how long. Even if (as is almost certain) we do overshoot 1.5ºC, the Paris Agreement’s requirement “to pursue efforts to limit the temperature increase to 1.5 °C” presumably means that we cannot simply recalibrate to meeting "2ºC"; it means that we must continue nett CDR at least until we come back to atmospheric CO2 concentrations consistent with below 1.5ºC.

Four alternative pathways with and without NETs

To examine the risks and costs in decarbonisation policies reliant on carbon dioxide removal an article by Obersteiner et al. in Nature Climate Change (paywalled) usefully shows four alternative global mitigation pathways, up to 2100. Briefly, the four ‘archetype’ pathways compared by Obersteiner et al. are:

  1. Late Century Carbon Dioxide Removal: Allowing large atmospheric concentration overshoot due to continued fossil fuel use falling at a rate of c. 2.7% per year (taking 25 years to fall by half) but  relying on gradual and then large scale Bioenergy Carbon Capture and Storage (BECCS) up to and beyond 2100 both to provide energy from burning harvested biomass and permanently storing very large amounts of CO₂ (first removed from the atmosphere during the plant growth ). This archetype matches most of the 2ºC scenarios produced for the IPCC’s Fifth Assessment Report (see WG3 Ch.6 pdf).

  2. Rapid Decarbonisation: Reducing global fossil fuel use at a rate of c. 6.7 % per year (halving in just 10 years) and stopping all deforestation, to achieve net zero global emissions before 2060 (see previous blogpost on Rockström et al 2016 ‘carbon law’).

  3. No Overshoot: Early ramp-up of negative emission technologies including BECCS from now to 2070 to ease transition from fossil fuels (again assumed to reduce at c. 2.7% per year, or halving in usage every 25 years), followed by rapid phase out of BECCS as carefully managed land use removals thereafter offset the minimal residual fossil fuel and cement emissions.

  4. Minimise CDR: In this pathway BECCS is developed early and then used continually through 2100 at limited scale.

Obersteiner et al. show the figure reproduced below of “Four archetypes of emission pathways leading to a 2 °C warming target with peak emissions in 2020”. The annual emission projections show marked differences between the pathways even though nett zero emissions are reached in all cases between 2050 and 2070. Note that the red line in each projection shows the cumulative (nett) CO₂ emissions measured by the right-hand scale. In a, c and d, fossil fuel phase-out with use halving every 25 years; only in b, “Rapid Decarbonisation”, does fossil fuel use halve every 10 years. In a and b the carbon price for land use including agriculture and forestry [presumably (?) a  tax on emissions or providing revenue for removals] is assumed to increase exponentially from US$0 to $200 per tCO₂; and in c and d it is constant at US$40 per tCO₂.

Early and sustained rapid mitigation is imperative to limit impacts and reduce implied need for NETs

Obersteiner et al.’s first major conclusion is in confirming that any and all delay in peaking and then declining emissions rapidly leads to “alarming [high risk] overshoot” levels in all pathway alternatives.

The second major conclusion is that pathway a, Late Century Carbon Dioxide Removal, the form of pathway that emerges from  most IPCC climate-economic modelling, is a highly risky strategy because of potential infeasibility due to biophysical, technical and political limits on large scale dependence on NETs. Therefore, to avoid these dangers, they argue that ramping up national mitigation efforts is urgently needed with the addition of near-term investment focused toward quickly reaching modest levels of negative emissions:

“considerations of both intergenerational equity and climate/ environment safety motivate early and moderate — rather than extreme — deployment of negative emission technologies as well as a timely peak in net carbon emissions as early as 2020. As a consequence all of the near-term and mid-century net emission reduction, targets should be reformulated to include targets of early action on CDR technology portfolios. Furthermore, our calculations point to significant indirect land use effects and other cascading impacts of delayed actions in phasing out fossil fuel emissions.” Obersteiner et al. 2018

In the IE-NETS project we have recently estimated (see Chapter 8 in our literature review) a total remaining Irish CO₂-only equity carbon quota share of the remaining “well below 2ºC” global carbon budget at about 500 MtCO2 as of end-2017. Inequitably allowing a global carbon budget share based on Ireland’s current share of emissions gives an inertia CO2 budget of 900 MtCO2 as of end-2017.  However, a quota based on responsibility (including historic emissions) and on capacity (the ability to pay for mitigation) would result in a quota much smaller even than the equity quota,

With current emissions now over 42 MtCO₂ per year and rising (including nett land use emissions), Ireland’s very limited remaining CO2 quota is currently being exhausted at an increasing rate. Turning the current upward trend around toward echoing any one of the Obersteiner et al. pathways will require major efforts in the short-term to decide on regulation, incentives and investment to enable overall energy demand reduction, low carbon energy supply and potentially rapid development of land-based carbon sequestration and carbon capture and storage that could underpin some level of BECCS and direct air capture (DAC) of CO₂ in future.

Increasingly, there are no easy or inexpensive choices in climate action: a portfolio of clearly communicated, strongly monitored and well funded efforts are needed to achieve actual decarbonisation. The analysis by Obersteiner et al. suggests that doing nothing is by far the most expensive, and highest risk, choice and that early and sustained action to cut emissions rapidly and deploy negative emissions at modest scale has significantly lower cost and less danger. Aligning global and national climate action with meeting the Paris targets requires immediate and sustained effort by all nations, especially those with high per person emissions and with the relative wealth to act fastest.

In societal reality, planning a national mitigation pathway and ensuring sufficient investment and oversight to achieve emission reductions and verifiable negative emissions both depend on early and sustained political decision-making. Research can outline the risks of inaction but it is policymakers globally and nationally who need to make difficult choices that determine whatever pathway is actually taken. Making those choices politically acceptable may not be easy but the physical reality of climate impacts from failing to make them is rapidly becoming clear, the imminent loss of almost all coral reefs, rapid Arctic ice loss and extreme heat episodes being the most strongly evidenced signs of escalating climate change impacts.

As the IE-NETs Literature Review has shown, climate research strongly shows that the often-easiest immediate political choice – doing little or nothing to deliver emission cuts or, secondarily, to enable early negative emissions – is the least cost-effective option simply because it gives no hope at all of delivering pathways achieving sufficient climate mitigation.


Larkin, A. et al., 2017. What if negative emission technologies fail at scale? Implications of the Paris Agreement for big emitting nations. Climate Policy, pp.1–25.

Obersteiner, M. et al., 2018. How to spend a dwindling greenhouse gas budget. Nature Climate Change, 8(1), pp.7–10.

Document Release: A Post-Paris Literature Review of Negative Emissions Technology, and Potential for Ireland

posted Jan 23, 2018, 3:42 AM by Alwynne Hanna McGeever   [ updated Mar 13, 2018, 8:16 AM by Paul Price ]

The main aim of the ie-nets project is to assess the scale and speed of negative emissions technology (NET) deployment that is required by currently envisaged decarbonisation pathways (globally and nationally), consistent with the Paris agreement goals.

The first Work Package for this project is a preliminary review of the most relevant international and Irish literature. The output of this work is now freely available to download here. The review comprises of two main parts:

Chapters 1-6: An overall review of international research specific to NET. Topics include climate policy, carbon budget management, strengths and challenges of various NET options, mitigation pathway modelling, risk assessment, governance;

Chapters 7-9: A review and analysis of the most relevant Irish research to date. Topics include Ireland’s emission pathway options, an estimation of possible national carbon quotas for Ireland and a preliminary assessment of national NET capacity in Ireland.

Additionally, there is a final concluding chapter with specific conclusions. For convenience, there is also a short Executive Summary of the complete report at the start.

Negative Emission Technology Options

We review the literature for six NET options with particular potential relevance to Ireland:

  • Soil Carbon Storage (SCS)

  • Biochar (BC)

  • Enhanced Weathering (EW)

  • Afforestation/Reforestation (AR)

  • Bioenergy with Carbon Capture and Storage (BECCS)

  • Direct Air Capture with Storage (DACCS)

Considerations for NETs include relative carbon removal capacity, cost, readiness, vulnerability to re-release of captured carbon, vulnerability to future climate change, biodiversity risk, energy penalty and land pressure. Our qualitative assessment of these diverse approaches is summarized in Table 1. For further detail see, in particular, Chapter 3 of the full review document.

Table 1: A simplified schematic to summarise the main policy relevant considerations for utilising NET options in Ireland. High uncertainty indicated by *

Potential capacity for Negative emissions in Ireland

Estimations of a remaining Irish carbon quota at the end of 2017 range from 590 MtCO (“equity” basis) to 1000 MtCO (“inertia” basis). At current emission levels, even the high end estimates of an Irish carbon quota could be exhausted well before 2040 (see Chapter 8).

A review of the NET research relevant to Ireland, and applying a simplistic model to estimate national NET capacity, found that NET approaches that are available for immediate deployment or expansion (afforestation, soil carbon management and biochar) had lower capacities and, if deployed fully, this capacity could saturate within 20 years. Higher capacity NET options with no early saturation limits (DACCS and BECCS) are not yet available for deployment at scale due to high costs and technological immaturity (see Chapter 9). Hence, while this review finds continued research and investment in NET options may increase the achievability of Ireland’s nett emission targets in future, immediate reduction in ongoing gross emissions must remain the highest priority for Ireland’s climate change mitigation actions.

Future Research

Future research priorities identified for Ireland include quantifying the indigenous bioenergy capacity (for potential use in BECCS), particularly under the conditions of future climate change, developing robust, physically-grounded, GHG accounting mechanisms through LCAs of NETs relevant bioenergy systems, and modelling feasible deep decarbonisation pathways for the Irish energy system as a whole with potentially ambitious incorporation of BECCS and/or DACCS.

ie-nets is a two year research project, funded by the Irish Environmental Protection Agency of Ireland (EPA) Research Programme 2014-2020 (grant number 2016-CCRP-MS.36). The project is being undertaken jointly by Dublin City University and Trinity College Dublin under the direction of Professor Barry McMullin (DCU) and Professor Mike Jones (TCD).

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