Category: Carbon capture & storage

Articles about carbon capture and storage

Article 6 and 1.5°C

June 20, 2022

The 56th session of the UNFCCC’s Subsidiary Body for Scientific and Technological Advice took place in Bonn over the past two weeks and one of the features of the session was further progress in operationalising Article 6 of the Paris Agreement, particularly after completion of the rule-book at COP 26 in Glasgow. But like many other aspects of the Paris Agreement and the global effort to significantly reduce emissions, Article 6 is making good progress but not rapid progress, yet it is rapid progress that is needed. My colleague, Malek Al-Chalabi, was in Bonn for SBSTA 56 and together we thought it would be useful to reflect yet again on the critical importance of this somewhat overlooked corner of the Paris Agreement. Article 6 was the last piece of the Agreement to fall into place in December 2015 and the last part to have its rule-book agreed, taking three years longer than every other part of the Agreement (but addmitedly not helped by COVID-19).

The importance of Article 6 stems from the clear message delivered by WGIII of the recent IPCC 6th Assessment Report; that carbon dioxide removals (CDR) are vital if the world is to achieve 1.5°C, the more ambitious goal of the UN Paris Agreement. This includes direct air carbon capture and storage (DACCS), afforestation (NBS or nature-based solutions), and bio-energy with carbon capture and storage (BECCS).

Arguably, there is no net-zero emissions without Article 6. Not all countries will have the same geographic and geological ability to harness or deploy CDR options or reduce emissions at the same rate, and the majority of countries cannot expect to reduce emissions to zero such that CDR is not needed. This is where trade is relevant.

Trade underpins economic activity and offers society the flexibility to provide the wide range of goods and services that we all benefit from. Trade is often the underpinning reason for foreign direct investment. It encourages the business sector to engage in projects and activities outside their traditional base with a view to bringing goods and services into that base. Cooperation between nation states is often pursued through some form of trading arrangement.

Article 6 of the Paris Agreement is a tailored and comprehensive policy that can enable cost reductions for lowering emissions via trade between nations. It allows countries to work together via ‘cooperative approaches’ through its voluntary nature. An International Emissions Trading Association (IETA), University of Maryland, and Carbon Pricing Leadership Coalition (CPLC) study has shown that cost reductions from cooperative implementation under Article 6 can be achieved through improved economic efficiency over independent implementation of countries’ nationally determined contributions (NDCs). According to the trade models used by the University of Maryland, the potential benefit is up to ~$250 billion per year in 2030.

In addition to the direct commercial benefit, it is the ‘net’ of ‘net-zero emissions’ that Article 6 unlocks. Large scale cross border investment that would otherwise not take place can result from the development and trading of carbon removal units. This is why Article 6 is so important – it helps all sectors and Parties to the Paris Agreement reach net-zero emissions. This can be illustrated with a simple example shown below. The country and the aviation sector both have a target of zero emissions, but neither is able to realise that goal through direct reductions. A regional partner has untapped carbon removal potential, but no need to use it as emissions are already at zero. By cooperating through the trading provisions of Article 6, the end result is that net emissions of 200 units CO2 across the three are brought to net-zero emissions.

While removals such as afforestation are well known, DACCS and BECCS have growing but still limited experience. That is why further international cooperation is needed alongside Article 6. In order to bring technologies like DACCS and BECCS to scale at an economic price and to further afforestation, cross border capacity building, joint research and development opportunities to pilot CDR options, and integrated policies and funding will also be required. This can make CDR more economically viable.

There are encouraging signs of international cooperation taking place, including countries agreeing to pilots and agreements using Article 6. However, these agreements are few and at the moment not used at scale. In order to maximize the use of Article 6, IETA has identified the following elements for governments to consider (see the full IETA paper here):

  • Announce whether and how the country will authorize Article 6 credits and/or accept towards the achievement of its NDC.
  • Provide a clear strategy and stable guidelines on which sectors, activities and vintages will be eligible for Article 6 credits.
  • Articulate how the use of Article 6 will help achieve the goals of the Paris Agreement.
  • Elaborate what policy framework the host country will adopt and how it will interact with the receiving country.
  • Establish an effective interaction between compliance instruments and the voluntary carbon market (VCM).
  • Support the emergence of a widely accessible traded market for carbon credits.
  • Ensure a suitable digital registry or other infrastructure for GHG accounting and reporting is in place.
  • Address key risks in the activity cycle and identify mechanisms to reduce them.
  • Emphasize the areas where capacity building is required and the role of international organizations.

Article 6 remains an innovative and new policy framework which has not been globally tested and used and it is understandable why some countries and regions may look to meet their own NDCs targets domestically instead of internationally. There are many areas to align, including how to formalize reporting mechanisms and ensuring that the deals that are made between countries (either directly or through business-to-business transactions) are set at prices and in frameworks that are transparent and benefit both.

However, if countries are to reach their NDCs independently of one another, it will be more expensive than working together and net-zero emissions will become an elusive goal. Article 6 has the potential to improve economic efficiency while helping reduce emissions across countries and sectors and provide access to opportunities only possible through cooperation. The opportunity exists to use it – and hopefully that can be maximized.

The role of CCS in hydrogen production

February 9, 2022

A recent report by Global Witness has cast doubt on the value that carbon capture and storage (CCS) can bring to the mitigation of emissions associated with hydrogen manufacture from natural gas. This is based on an analysis of the Quest CCS project in Canada. However, the report fails to discuss the full context in which this project was developed and therefore draws an incorrect conclusion as to the benefits delivered by the project and the prospect for CCS linked to future hydrogen production.

Just over 20 years ago, I attended my first meeting of the Shell Canada Greenhouse Gas Advisory Panel. Shell Canada had established this panel to recommend and oversee measures to manage the carbon footprint of its operations at that time. Led by the then President/CEO, the panel included Shell Canada staff, representatives from Canadian and international NGOs and First Nations, and me representing the broader Shell group.

We met 2-3 times per year up until the mid-2000s and the Shell Canada team took forward a number of the panel’s recommendations to reduce emissions at Shell’s operations in Alberta. One of the earliest discussion points was around the need to develop CCS at Shell’s Scotford Complex in Alberta. These were the early discussions that led to the Quest CCS project.

Shell opened the Scotford Complex in 1984 with a refinery and chemicals plants, then expanded it in the early 2000s to process heavy oil into refined petroleum products. To do this, Scotford incorporated an ‘upgrader’, a unit that transforms bitumen into a light/sweet synthetic crude oil by fractionation and hydrogenation (improving the hydrogen to carbon ratio of the oil).

At the time, some of the hydrogen at the Scotford Complex originated from a nearby industrial facility where it was a by-product. But as Scotford grew with increasing production, Shell built a steam-methane reformer (SMR) to produce its own hydrogen. This is a process where natural gas is converted to hydrogen, with the remaining carbon being emitted as carbon dioxide from the process. A simplified representation of the process is;

CH4 (natural gas) + 2H2O (water as steam) –> CO2 (carbon dioxide emitted) + 4H2 (hydrogen produced)

In the case of a conventional SMR, which the original unit is, additional CO2 is also emitted from the process when natural gas is burned to provide energy.

Fast forward to today, Quest CCS has been running since 2015 and captures just over one million tonnes of CO2 each year – more reliably and at a lower cost than expected – with the CO2 coming from the reaction outlined above in the steam reformer that produces hydrogen for the upgrader.

Quest was designed as a million-tonne unit to capture one third of the emissions from the Scotford upgrader. Its purpose was to demonstrate not only that CO2 could be captured, but also that it could be stored more than 2 km underground in a geological formation that lies under much of Western Canada called the Basal Cambrian Sands. Quest is part of a knowledge sharing effort with the governments of Alberta and Canada to encourage wider use of CCS technology and bring down future costs. As such, its designs, emissions data and certain intellectual property are publicly available on the Government of Alberta website.

Quest was not, however, designed to capture all of the CO2 emissions associated with steam reforming of methane to make hydrogen. Nor has Shell claimed in its publicity that Quest is capable of capturing all CO2 emissions from the hydrogen plants or the upgrader. Annual performance reports on the Government of Alberta’s website have been audited and reviewed, and reflect an accurate characterization of what Quest has achieved to date: it has successfully captured and then permanently stored underground more than six million tonnes of CO2.

And importantly, Quest was not designed to produce blue hydrogen, and as such, it should not be used as an example of blue hydrogen production. Rather, Quest was designed to demonstrate that capture and storage of CO2 does work; and it has done just that.

Diagrammatic representation of Scotford CCS. Source: Shell Canada

Since Quest began operating, the energy transition has gathered pace and the role of hydrogen as an energy carrier has become a focus of attention. As a result, how hydrogen is produced has also become an important consideration. There are two approaches under consideration for a world that needs to head towards net-zero emissions.

  1. Green hydrogen – this is produced by the electrolysis of water using electricity from renewable energy sources. The basic process dates back over 200 years, but it has remained a relatively small scale process, until very recently. Now electrolysers are growing rapidly in size with Shell amongst a handful of companies installing very large units. In July last year, Europe’s largest PEM hydrogen electrolyser began operations at Shell’s Energy and Chemicals Park Rheinland, producing green hydrogen.
  2. Blue hydrogen – this is produced through the conversion of natural gas to hydrogen, with a very high percentage of the carbon dioxide which would otherwise be emitted by the facility, captured and geologically stored. Although the Quest CCS project captures and stores CO2 from hydrogen production, this is not a blue hydrogen facility. That is because only a portion of the CO2 is captured, as per the design criteria discussed above.

The Global Witness report has drawn on the Quest experience and used it to criticise the carbon footprint of blue hydrogen. The report concludes that future blue hydrogen projects should not be considered based on the observation that the existing hydrogen facility on which Quest is attached continues to emit a good portion of total CO2 produced.

But the analysis fails to contextualize Quest and doesn’t consider that future blue hydrogen projects would be designed very differently to Quest and the associated hydrogen plant, even employing different process technology for the methane conversion itself which in turns makes CO2 capture much more manageable and cost effective. For example, the proposed Polaris CCS project that Shell is planning for Scoford’s refinery and chemicals plants would include what’s called ‘post-combustion capture’ which has the more than 90% CO2 capture rates needed to produce blue hydrogen.

The route towards the current best process for blue hydrogen is described in a white paper produced by Shell Catalysts and Technologies, with its infographic shown below. The paper indicates the possibility of >99% CO2 capture in the Shell gas partial oxidation process (SGP).

Hydrogen processes with CCS. Source: Shell Catalysts and Technologies

As the century unfolds and the energy transition takes hold, hydrogen may become an important part of the new energy system. So society needs to be able to produce it at scale and do this quickly. Hydrogen from renewable sources and from natural gas with CCS will be required to meet demand. Both routes are more than capable of delivering hydrogen with a very low carbon footprint and ultimately cost will decide the winner, including the carbon cost associated with managing any ongoing emissions attributable to either process.

Article 6 at COP26

October 11, 2021

My home country, Australia, seems to reside permanently in the international climate doghouse, but a closer look reveals that they have made steady progress on some of the less advertised fronts related to mitigation. This was highlighted again recently when the government’s Energy and Emissions Reduction Minister Angus Taylor announced that carbon capture and storage (CCS) projects would be eligible for emission reduction credits.

This might seem like a distraction to some, but Australia has been forging a clear path towards growing its carbon removal capacity for some years now. The Federal Emissions Reduction Fund (ERF) has long targeted opportunities in soil carbon, forest management and reforestation and now CCS is added to the list. Short of a miracle in energy technology development and deployment, the current mechanisms for energy supply do not hold within them a net-zero emissions solution available within 30 years, so it is only through the addition of direct carbon dioxide management in the form of removals that the goal of the Paris Agreement can be met. Unfortunately, this doesn’t seem to be widely appreciated, with the exception of the United States and their 45Q tax incentives for CCS, Canada with their early demonstration projects and Australia with its behemoth Gorgon CCS project, creation of the Global Carbon Capture and Storage Institute and domestic focus on removals. Other countries are now scrambling to establish similar initiatives, but are somewhat lagging.

The case for CCS and carbon removals is an easy one to make – it emerges from any credible analysis of the energy system that accounts for likely future energy demand, real world deployment rates and the expected fossil fuel legacy that will persist into the 22nd century even as significant reductions in use are made. Depending on assumptions, removals can stretch to a trillion tonnes of carbon dioxide over the course of the century. It is only in a scenario with a very constrained future energy demand that removals become less important, but still don’t disappear. The chart below, which I have posted before, shows the four IPCC 1.5°C archetype scenarios (P1, a high sustainability consciousness develops across society, to P4, a technology driven society with high energy demand and technical solutions to environmental issues) and the Shell Sky 1.5 scenario – all require carbon removals. In the P1 scenario sink use is quite low, highlighted by an end to land based anthropogenic emissions and the subsequent development of the land as an enhanced sink from mid-century on, at about 5 Gt per year drawdown of carbon dioxide. P1 makes no use of geological storage. By contrast, the P4 scenario makes very extensive use of geological sinks with BECCS playing a substantial role even as land based emissions are eventually reigned in.

So how does all the above relate to COP26? Of course ambition is very much on the agenda and removals are required to deliver on that ambition, but so are many other steps. However, one of the features of carbon removals is that they will likely have to emerge through cooperative action between governments. Remaining emissions and the availability of removal sinks probably won’t exist in the same geographies, so a global trade in emission sinks will need to emerge. This would happen under Article 6 of the Paris Agreement, which still remains as unfinished business after the rulebook negotiations at COP24 in Katowice. Article 6 establishes a framework for cooperative action between countries in realizing their NDCs, which includes trading carbon units across borders.

The charts below illustrate how a standstill in global emissions (at 300 units in the illustration) is brought to net-zero through cooperative action between governments and the aviation sector. Large scale cross border investment results from the development and trading of carbon units, including removals, that would otherwise not take place. This is why Article 6 is so important – it helps all sectors and Parties to the Paris Agreement reach net-zero emissions.

While the UK Government has many ambitious plans for COP26, and Article 6 is certainly among them, I believe that agreement on the Article 6 rulebook is the most important outcome needed from Glasgow. Apart from its future value to society, an agreement on this difficult piece of rule-making would demonstrate that countries can work together to achieve an outcome that may not be in their immediate self-interest. Article 6 brings a rigour to emissions reporting and accounting that we must have for net-zero emissions. It introduces concepts such as carbon budgets and emissions inventory adjustments for trade to take place, which progressively caps the emissions of nationally determined contributions and forces them towards exact quantification, rather than narrative description. Of course nations aren’t required to use Article 6, it’s voluntary, but once they choose to they must also choose accounting rigour.

After the failure to agree on the Article 6 rule-book at Katowice, great progress was made at COP25 in Madrid, but final agreement still wasn’t possible. Nevertheless, a text emerged that would do the job, although it was entirely bracketed. But the text did capture the key elements that are required for Article 6 to function;

  • Removals specifically referenced.
  • A simple but robust approach for adjusting nationally determined contributions (NDC – the national plan for emissions reduction and adaptation put forward by a country) when an Article 6 transfer takes place.
  • A centralized accounting and reporting platform, with a clear focus on the avoidance of double counting of mitigation actions.
  • The creation of a supervisory body for the 6.4 mechanism.
  • Specifications for the design of a 6.4 activity and subsequent issuance of associated emission reduction units.
  • An approach to meet the requirements for adaptation funding required under 6.6 of the Paris Agreement.
  • A transition arrangement for ending the Clean Development Mechanism (CDM) of the Kyoto Protocol. The CDM has left several countries holding project carbon units that they are keen to monetize so as to support the underlying internal project investment.
  • A simple framework giving some structure to Article 6.8, the non-market approach cooperation.

Nevertheless, some disagreement between countries remains and these issue will need to be resolved in Glasgow.

There is a set of issues related to the scope of an NDC and whether some activities that are in addition to the NDC and involved in a transfer should be subjected to the same adjustments as the Madrid text outlines. This feels like a distraction for two reasons; the NDCs should rapidly expand to cover all activities within an economy and if there are activities still not covered by the NDC, they have no place under Article 6 anyway as this provision of the Paris Agreement is about cooperation to achieve NDCs.

Another tough issue has been the need to give meaning and substance to 6.4 (d) To deliver an overall mitigation in global emissions. The proposal in the Madrid text is to cancel a portion of the emission reduction units issued to the 6.4 activity, but this is unnecessarily punitive. It also risks pushing all activities into simple 6.2 transfers, which would undermine the whole purpose of having a project based mechanism which is more suited to many countries. The discussions in Glasgow simply need to recognize that, by definition, a 6.4 activity and related transfer with NDC adjustments always results in an overall reduction in global emissions. This is illustrated in the diagrams above and is the inherent purpose of an emissions trading structure.

Finally, there is the lingering problem of how best to wind up the CDM and what then becomes of the projects still delivering reductions and the legacy unused CERs sitting in registry accounts. For projects that continue to deliver reductions, the answer seems straightforward – they continue to operate, produce CERs and these are transferred under the provisions of 6.2, which ensures corresponding adjustments to NDCs. In the case of legacy units, I think the IPCC have answered the question, both in the 2018 SR15 and the 2021 AR6 reports. Both reports show that the temperature rise is now around 1.2°C and both offer a carbon budget requirement from 1.1.2018 and 1.1.2020 respectively to ensure that 1.5°C isn’t passed. By rebasing the climate issue in 2020 (in the case of AR6), anything that happened before that is now irrelevant in that it is part of the 1.2°C baseline. The carbon budget they developed has subsequently informed Parties on their NDC requirements and is already being used by the UNFCCC to assess the NDC gap . Adding pre-2020 units to current mitigation activities is simply undermining the carbon budget calculation.

With an agreement hopefully reached on Article 6 in Glasgow, the spotlight will then turn to national governments to open up the possibility of cooperative arrangements. This could come through linking of trading systems, opening up trading systems to external units and encouraging the private sector to develop mitigation projects through Article 6.4. Importantly, governments should also follow the lead of Australia and develop protocols for removals, as these are the units that will be in particular demand as net-zero emission goals and targets need to be met. Europe, in particular, will need to accelerate its removals thinking, an area where it is lagging in its mitigation efforts.

On to Glasgow!

The simple climate maths the IPCC didn’t fully explain

August 19, 2021

When I first started delving into the issue of climate change about 20 years ago, the clarion call of the day was to reduce emissions by 50% by 2050. Today, as we all know, the call is for net-zero emissions by 2050. Last week we also heard again from the Intergovernmental Panel on Climate Change (IPCC) with the release of the first part of the 6th Assessment Report (AR6), which the United Nations Secretary General called a ‘code-red for humanity’. But both the call in 2001 and again in 2021 are entirely consistent. It’s not the climate science that has changed, just the carbon maths associated with it.

As the IPCC clearly state in Part D of the Summary for Policymakers of AR6-WG I;

  • This Report reaffirms with high confidence the AR5 finding that there is a near-linear relationship between cumulative anthropogenic CO2 emissions and the global warming they cause. Each 1000 GtCO2 of cumulative CO2 emissions is assessed to likely cause a 0.27°C to 0.63°C increase in global surface temperature with a best estimate of 0.45°C. This is a narrower range compared to AR5 and SR1.5. This quantity is referred to as the transient climate response to cumulative CO2 emissions (TCRE). This relationship implies that reaching net zero anthropogenic CO2 emissions is a requirement to stabilize human-induced global temperature increase at any level, but that limiting global temperature increase to a specific level would imply limiting cumulative CO2 emissions to within a carbon budget.

While the biggest difference between now and 2001 is the shift in the goal from below 2°C to 1.5°C which in turn has contributed to the change in required emissions trajectory, this is not enough to explain the shift in the required outcome by 2050. That change is more a function of the cumulative carbon math associated with any level of warming.

To limit the temperature rise to 1.5°C, the notional carbon budget based on the above best estimate of TCRE is 1.5/0.45*1000 =  3330 Gt CO2 and for 2°C it is 4440 Gt. This is effectively targeting the central estimate in a range and is a calculation you might do before emissions start. However, we already know from IPCC AR6 that cumulative emissions of 2390 Gt correspond to a 1.07°C temperature rise in 2010-2019 vs. 1850-1900. They also indicate that the remaining carbon budget from 1.1.2020 for 1.5°C is 400 Gt and 2°C is 700 Gt for a 67% likelihood, which implies an overall carbon budget of 2790 Gt for 1.5°C and 3090 for 2°C with a good degree of certainty.

In the following calculations and accompanying charts I will work on the basis of a simple linear reduction in emissions to net-zero from a particular point in time to calculate the overall cumulative emissions. Returning to 2001, the annual CO2 emissions (from energy, cement and land use) were approximately 30 Gt, the cumulative emissions from 1850 at that time were about 1700 Gt and a linear reduction pathway from 2001 for 2790 Gt final cumulative emissions (1.5°C) means net-zero emissions in about 2073. This is illustrated in the chart below.

As noted for 2001, cumulative carbon dioxide emissions since 1850 were at 1715 Gt (Source: Our World in Data), which means net-zero emissions in 2073 for 1.5°C and 2123 for 2°C. Back in 2001 the focus was more on 2°C, so targeting well below 2°C, to completely avoid the 2°C threshold, would mean net-zero emissions around 2100 and therefore a 50% reduction in emissions by 2050 assuming a linear decline.

But twenty years later the story is very different. At the time of the IPCC Special report on 1.5°C cumulative carbon dioxide emissions had reached 2300 Gt, so a linear reduction to net-zero had a target date of 2040. For 2°C it was 2077. In fact the IPCC opted for scenarios with a steeper early reduction pathway, and therefore targeted 2050 for net-zero emissions, but that means a very steep early reduction of over 50% by 2030 to balance the longer tail to 2050. With twenty further years of rising emissions, a considerable portion of the 2001 carbon budget had been consumed and therefore the date for net-zero emissions had moved forward in time dramatically.

In fact, for each year that emissions don’t reduce, the requirement for net-zero emissions comes towards us by a year, effectively narrowing the gap for action by two years. The IPCC Special Report on 1.5°C was baselined from 1.1.2018, so another four years has passed (or will soon pass). Even the recent IPCC AR6 is two years out of date now in terms of its carbon budget baseline. This rapidly shifting picture is shown below. In 2015 the target year for 1.5°C is shown to be 2042, a gap of 27 years, but by 2019 the target year is 2038, a gap of only 19 years.

Should carbon dioxide emissions remain at 40 Gt (below the pre-COVID high) for the coming few years, the available carbon budget for 1.5°C is rapidly consumed, as illustrated in the chart below. By 2025 net-zero emissions would be required by about 2033 and by 2029 net-zero emissions would be required before 2030, in other words the available carbon budget will have been consumed.

All the above presupposes that emissions cannot go below zero in the future, thereby drawing carbon dioxide out of the atmosphere and eventually correcting any overshoot of the carbon budget and its associated temperature goal. But negative emissions are a possibility, through the implementation of large scale air capture systems with geological storage (BECCS or DACCS) and enhancement of natural carbon uptake in the biosphere via programmes such as those that increase global forest cover and improve soil carbon management in agriculture.

Today, the carbon budget is still a rather arcane subject, well understood by a few but not widely appreciated in terms of relevance to managing surface temperature. That understanding will need to improve rapidly so policymakers can develop better mechanisms to manage it, also ensuring large scale deployment of atmospheric drawdown practices and technologies.

Pathways to 1.5°C

June 11, 2021

In 2018 when the IPCC released their Special Report on 1.5°C, they presented four archetype scenarios to help readers understand that there were fundamentally different approaches to limit long term warming to 1.5°C or below. The scenario pathways are shown below and vary significantly in their approach, time horizon and use of sinks.

Source: IPCC SR15

All four scenarios (P1, P2, P3, P4) are based around the same carbon budget, or total cumulative emissions of 420 Gt from 1.1.2018 consistent with providing a 66% chance of limiting warming to 1.5°C. Whether the carbon budget is aligned with 420 Gt (67th percentile) or 580 Gt (50th percentile), it represents a very limited amount given that annual CO2 emissions are in excess of 40 Gt, so these represent 10-15 years of emissions at current levels. Since this IPCC publication, a further 160 Gt will have been emitted by society by the end of 2021, meaning that the budget is reduced to 260 – 420 Gt.

Source: IPCC SR15

In attempting to align with a very limited carbon budget, the P1 scenario imagines a world of falling overall energy use and a very rapid shift away from fossil fuels. There is no use of geological storage of CO2 and a modest reliance on natural sinks, although in doing so the world must shift away from net-deforestation by the 2040s. By contrast, the P4 scenario sees increasing demand for energy and as a consequence, a much more difficult decarbonisation journey that involves considerable use of sinks in the second half of the century. Notably, the P4 scenario exceeds the carbon budget by quite some amount with peak emissions to the atmosphere of 900 Gt, before reining in the amount to 200 Gt by 2100. This results in P4 being a so-called overshoot scenario, in that the world exceeds 1.5°C during the century before returning to 1.5°C and below by the end of the century.

Source: IPCC SR15

All the above might seem a bit academic, but it became very real recently when the IEA released their 1.5°C scenario and some commentators began comparing it to one of the very few other 1.5°C scenarios, notably Sky 1.5 from Shell.

In fact, the two scenarios are at near opposite ends of the P1 to P4 spectrum.

The IEA 1.5°C scenario looks at the period from 2020 to 2050 and presents a proposal for the problem of containing emissions to a 500 Gt carbon budget (the 580 Gt IPCC number less 80 Gt for the years 2018 and 2019). Apart from recognising that the land based system is likely to reduce this budget by a further 40 Gt over the period (i.e. reducing it to 460 Gt), the analysis limits itself to the energy system and the changes that would be required to meet a 460 Gt cumulative emissions constraint within a 30 year time frame. As is the case in similar scenarios, including Sky 1.5, their analysis assumes rapid electrification of final energy (e.g. electric cars instead of gasoline) and makes use of renewables  and nuclear power generation to produce the electricity. They introduce hydrogen as an energy carrier, make use of bioenergy and include carbon capture and storage (CCS) where fossil fuel remains in use. For the latter, the IEA deploy CCS directly on facilities that use fossil fuels and indirectly through direct air capture for fossil fuel use in applications such as aviation.

All the above steps are well understood, but even given rapid and stretching deployment rates of all technologies, these steps are unlikely to contain emissions to less than 500 Gt in under thirty years. This is because of the expected increase in overall energy use, a consequence of economic growth, the general rise in population and the shift of billions of people from very low energy use lifestyles to at least modest energy use, a simple outcome of development and the provision of basic services like lighting, clean water, food refrigeration and some mobility.

As such, energy modelers looking at a very constrained time frame of 30 years must make the assumption that energy growth can be contained or even fall, as in the IPCC P1 scenario. This is exactly what the IEA have done to meet the carbon constraint. In the 1.5°C Scenario primary energy demand falls from 612 EJ in 2019 to 543 EJ in 2050, a drop of over 10%. Efficiency will certainly help deliver such an outcome and the use of renewable electricity gives the story a big boost as the thermal losses in power stations vanish, although new losses emerge through the use of transmission and storage. But the big story is the widespread assumption of behavioural change across society to reduce energy demand. The chosen measures include steps such as;

  • Ride-sharing in all urban car trips
  • Reducing motorway / freeway speeds to below 100 kph / 60 mph.
  • Increasing temperatures in air conditioned vehicles and buildings.
  • Lowering temperatures in heated buildings.
  • Replacing short flights with high speed rail.
  • Limiting long haul air travel to 2019 levels.

With low energy demand and high deployment rates of new energy technologies it then becomes possible to resolve the carbon budget within a 30 year time frame.

At the other end of the spectrum is the Sky 1.5 scenario, which tackles the problem of a limited carbon budget in a very different way. Sky 1.5 looks at the period from 2020 to 2100, an 80 year time frame, and starts with an expectation of rising global energy demand, even assuming significant energy efficiency improvements across society. The growth in population and the demand for energy services, including significant new demand from developing countries for basic services, cannot be contained and energy demand rises. This immediately poses a challenge in that rising demand more quickly consumes the available carbon budget at the front end, when alternative energy technologies and sinks have not been deployed.

Sky 1.5 also recognises that for many energy technologies, the 2020s still remain a period of development and limited deployment and even for more mature technologies such as solar and wind, a period of early growth where change on a global scale will remain limited.

The solution to this approach is to accept that, at least in the short term, the carbon budget may be consumed and the temperature it is linked to (1.5°C in this case) potentially surpassed for a period of time. The subsequent rapid deployment of sink capacity, both manmade in the form of air capture with geological storage and natural as reforestation, then offers the possibility of a period of net-negative emissions later in the century, to redress the imbalance and reduce cumulative carbon dioxide emissions and therefore temperature. This is the approach that Sky 1.5 takes, as do the IPCC P3 and P4 scenarios. Sky 1.5 takes this approach out of necessity, in that the scenario reaches a limit on energy technology deployment and does not foresee a fall in energy demand.

The end carbon budget for both the IEA 1.5°C scenario and Sky 1.5 are similar, but the IEA restricts itself to a thirty year time-frame, whereas Sky 1.5 operates over an eighty year time-frame. Sky 1.5 is also remodeled by MIT within their integrated assessment model to give a temperature outcome, rather than simply using the IPCC central estimate for a carbon budget. The two scenarios are attempting to answer the same question, but take very different approaches to doing so. There is no right or wrong here, just different ways of solving a tough problem.

Note: Scenarios don’t describe what will happen, or what should happen, rather they explore what could happen. Scenarios are not predictions, strategies or business plans. Please read the full Disclaimer here.

A ten year reduction challenge for the USA

May 4, 2021

In April, at the opening of the White House Climate Summit, President Biden announced the United States Nationally Determined Contribution (NDC) for the period up to 2030, encompassing a target of greenhouse gas reductions 50-52% below 2005 levels. The US Greenhouse Gas inventory is available on the US EPA website and is summarised in the table below.

Sector and gases(Mt CO2e)2005Latest data for 2019
CO2 Fossil Fuel Combustion5753.54856.7
CO2 Non-Energy & Industrial381399.1
CH4 from all sources686.1659.7
N2O from all sources455.8457.1
HFCs, PFCs, SF6, NF3 from various industries146.5185.6
Total Emissions (Sources)74236558.3
LULUCF Emissions16.823.5
LULUCF Carbon Stock Change(804.8)(812.7)
Net Emissions (Sources & Sinks)6635.05769.1

Given a baseline of 6635 Mt CO2e, a 50% reduction in 2030 would require US emissions to be 3318 Mt or lower in that year. The 2019 data represents a reduction of 13% over 2005, so the reduction in the next 10 years must be nearly triple that of the last 15 years. The reduction seen to date from fossil fuel combustion is running slightly ahead of the overall improvement, with a reduction from 2005 to 2019 of nearly 16%.

The goal that President Biden put forward is aligned with a strategy that is designed to achieve a goal of net-zero emissions for the US in 2050. Recently, the Shell Scenario team released a US Sketch outlining one possible pathway to such an outcome. The Sketch is illustrated below (N.B. 2020 figures are a pre-pandemic view of US emissions which the US is approaching again as the recovery gains momentum).

The Sketch provides the opportunity to look at the nature of the transition required in the 2020s for the NDC. The Sketch energy system emissions in 2030 are 3440 Mt against a 2005 baseline of 6030 Mt (small differences in baselines result from different categorizations of emissions), or a reduction of 43%. While this isn’t exactly aligned with the NDC, it could be in that the NDC makes specific reference to a major expansion of sink capacity through enhanced soil carbon uptake in the agricultural sector.

Key elements of the journey to 2030 outlined for the US in the Sketch are as follows;

  • In 2020 (pre-COVID calculation) the US generated 3970 TWh of electricity, with 80% from coal, gas and nuclear. Solar and wind made up less than 10% of the total. By 2030 in the Sketch, the generation mix has shifted to natural gas and solar each making up about 25% of the total, with wind, nuclear and coal combined at around 40%. Notably, total electricity generation has increased to 5720 TWh, or 43% over 2020. This is in a pathway that still sees electricity system emissions at 600 Mt in 2035, the year President Biden has targeted for a zero emission system. His goal is about 5 years ahead of the Sketch.
  • The increase in electricity consumption comes from an increasing proportion of electricity in final energy, displacing gasoline in cars, natural gas in homes and coal in industry. Electrification is a major lever for decarbonisation. The proportion of electricity as final energy rises in a decade from 22% to 35%, breaking a near century long trend which if continued, would otherwise see it rise to 25% at most.
  • Over the 2020s, solar generation of electricity grows fastest, increasing by a factor of nearly 12 in a decade. The U.S. installed 19.2 gigawatts (GWdc) of solar PV capacity in 2020 to reach 97.7 GWdc of total installed capacity. With a utilisation factor of 15-20%, this could be expected to generate around 150 TWh of electricity, although the Energy Information Agency reported a total of 130 TWh (perhaps because the capacity at the start of the year was 79 GWdc). In any case, capacity by 2030 will need to grow to at least 1 TWdc, assuming some efficiency improvement in new installations compared to existing facilities. With a year-on-year installation growth of 30%, the US could be installing some 260 GWdc per year by 2030, bringing the total installed capacity to 1.2 TW by the end of that year. Very large scale energy storage will also have to deploy to support solar.
  • The Sketch also shows a three-fold increase in wind generation throughout the 2020s and importantly, no decline in nuclear generation. The latter becomes increasingly important as other non-intermittent generation sources decline in use.
  • Electric vehicle (EV) deployment is an important part of the trend towards electrification and it emerges rapidly in the Sketch. By 2030 the US will need to see 20% of all passenger vehicle use as electric, with hydrogen fuel cell vehicles rapidly appearing in the large SUV sector. At the moment, there are about 1.5 million EVs on the road, out of a total US passenger vehicle fleet of some 280 million. To reach a level of 20% EVs in terms of use, sales will need to climb rapidly from some 400,000 vehicles per year now, to over 13 million in 2030, or nearly 80% of all sales. This represents a year-on-year growth rate in EV sales of 42% through the decade.
  • Road freight makes less use of electricity, although it does impact the lighter end of the freight market. For larger, longer haul freight trucks, hydrogen emerges during the 2020s, with some 200,000 trucks on the road by end of the decade. This is still relatively small, but the sector is non-existent today. In the second half of the century in the Sketch, hydrogen becomes the dominant fuel for heavy road freight.
  • Natural gas, propane and oil are used widely in the US for cooking and/or heating in homes. Although the majority use electricity for cooking, heating is provided mostly by gaseous hydrocarbon fuels. In the US Sketch, heating and cooking in residences shifts from 13% electricity to 42% electricity in just a decade. Of all the transition tasks ahead, this may be the most challenging in that it involves convincing millions of households, individual consumers and landlords to change their behaviour, refit existing properties, invest money for the change and in some instances make use of a less preferred energy option.
  • While electricity already plays a significant role in light industry, this is not the case for heavy industry where very high temperatures and high thermal loads are often required for conversion processes. Heavy industry energy use in the US is currently three-quarters gas, coal and biomass and one quarter electricity. This begins to shift rapidly and by 2030 in the Sketch, 40% of energy demand for heavy industry is supplied by electricity. In addition, hydrogen is emerging, with the first industrial installations making commercial use of this fuel. While the amount is small in 2030 it could mean significant development, design and engineering of new processes in a limited amount of time. Alternatively, the amount could point to natural gas being topped up with hydrogen as a mixed fuel for industrial furnaces, prior to converting whole processes over to hydrogen based fuels.
  • The many changes across the energy landscape result in steep decline in the use of fossil fuels in the Sketch, with coal falling fastest. By 2030 there is a 40% reduction in coal use, a 14% reduction in natural gas and a 25% reduction in oil within the economy, compared to 2020 (pre-COVID) use.
  • But even by 2050 in the Sketch, natural gas and oil still play an important but significantly diminished role in the US economy. That points to the need for carbon capture and storage (CCS), both directly linked to facilities and indirectly as an atmosphere removal mechanism (e.g. BECCS). The US already has the most mature CCS industry in the world, underpinned by years of enhanced oil recovery using carbon dioxide. But an order of magnitude change is required here as well during the 2020s, with a shift from some 30 mtpa carbon dioxide stored to some 300 mtpa.

While the Sketch does not require nature based solutions (NBS) for the US energy system to reach net-zero emissions by 2050, natural carbon sinks do provide an additional lever to support the transition and the NDC also discusses this aspect of emissions mitigation. In the US, national forests cover 193 million acres, an area larger than Texas. Apart from their significant bioenergy potential, forests act as natural carbon sinks. The US could reduce CO2 emissions by up to 300 million tons a year by 2050 through afforestation – the planting of new trees where there were none before. While new forests represent significant additional sinks, there is also potential to expand areas such as wetlands and mangrove swamps, and perhaps most importantly to encourage farmers to adopt practices that enhance soil carbon. The US NDC references this opportunity. 

The rates of change outlined above are substantial, with year-on-year growth rates for several new energy technologies of 20-50%, depending on the sector. While growth at this level can be sustained when a sector is very small and this has been observed for renewable energy deployment, it becomes increasingly difficult as the sector grows and absolute levels of deployment become very large. Many of the sectors mentioned will face this issue during the 2020s. Nevertheless, the Sketch was designed to show what is possible given the right policy levers for innovation and deployment, sufficient and targeted financing and overall transition design.

Note: Scenarios don’t describe what will happen, or what should happen, rather they explore what could happen. Scenarios are not predictions, strategies or business plans. Please read the full Disclaimer here.

The importance of sinks

March 2, 2021

A review of the 2018 IPCC Special Report on 1.5°C shows that all four archetype scenarios (P1, P2, P3 and P4) make use of sinks – or the ability to remove carbon dioxide from the atmosphere and store it geologically or retain it within the land. The reasons for needing to do this fall into two categories;

  1. The point at which net-zero emissions is required (i.e. 2050) comes before all anthropogenic emissions can be stopped, so remaining emissions have to be balanced with sinks to remove the same amount of carbon dioxide from the atmosphere as added by remaining sources.
  2. By the time net-zero emissions is reached, the carbon dioxide load in the atmosphere has exceeded that associated with 1.5°C of warming, so sinks are required to lower atmospheric levels at a faster rate than natural decline, ensuring a 1.5°C or lower outcome by the end of the century.

The four scenarios are shown below.

Diagram Description automatically generated
Source: IPCC SR15

In the P1 scenario sink use is minimal, highlighted by an end to land based anthropogenic emissions and the subsequent development of the land as an enhanced sink from mid-century on, at about 5 Gt per annum drawdown of carbon dioxide. P1 makes no use of geological storage. By contrast, the P4 scenario makes very extensive use of geological sinks with BECCS playing a substantial role even as land based emissions are eventually reigned in. But why is there such a difference in sink use between these scenarios?

A deeper dive into the four stories reveals an interesting trend – an almost linear relationship linking cumulative sink capacity to 2100 with the growth in final energy demand (measured as the increase in 2050 demand over 2010 demand).

This trend points to two aspects of the energy transition which are in turn related to the two reasons for needing sinks outlined above;

  1. As energy demand increases and emissions rise from sectors of the economy where no large scale mitigation solutions currently exist, perhaps a sector like aviation, greater and greater sink capacity will be required.
  2. With energy demand rising quickly and a starting dependency on fossil fuels to meet that demand, the carbon budget that equates to 1.5°C is exceeded well before the point of net-zero emissions, which then means extensive sink capacity is required to remove this carbon from the atmosphere and meet 1.5°C later in the century.

That then brings into focus the question of energy demand. In the Energy Transformation Scenarios released recently by Shell, all three scenarios show rising energy demand through the century, although in the Sky 1.5 story this is curtailed from the 2070s onwards due mainly to efficiency practices and rapid electrification (which can also lead to greater efficiency). 

Energy demand growth across all three Shell scenarios contrasts with the IPCC range, where the P1 archetype imagines a fall in energy demand. But a fall in energy demand over the next thirty years is in sharp contrast with history, where energy demand has only ever risen, even as very significant efficiency gains have spread throughout society.

For comparison, over the last 30 years (to 2019), world total primary energy grew by 68%. This derives from GDP growth of 180%, and a Shell assessment of total energy service growth of 130%. In a discussion on energy growth, it is important to focus on non-OECD countries, because that is where the relationship of GDP growth to energy service growth is strongest. OECD countries are not far from the point where energy service growth is matched by energy service efficiency improvement and hence energy demand stays flat. In the last 30 years, non-OECD primary energy growth was over 80% of the global total and in the next 30 years we may see non-OECD growth making up almost all of the global energy demand increase. But this is the portion of the word where population increase continues in many countries and where access to energy is growing at a rapid rate. This in turn creates new demand for energy services. In short, we are more likely to underestimate energy demand than overestimate it.

There are also other reasons for continued energy demand growth.

  • Efficiency rebound on a macro scale is widespread and often not recognised. For example, when I was growing up in Australia in the 1960s, air conditioned cars hardly existed. I still remember when we lived outside the country in an American community (in SE Asia) in 1967 and I got in my first air conditioned car; I really couldn’t believe such a thing was possible. Today, you can’t buy a car without air conditioning. So in the 1960s we had maybe 50 million upscale cars globally with expensive inefficient air conditioners, but now we have over one billion cars with cheap efficient air conditioners. That’s lots more energy than the 1960s.
  • Society continues to find and adopt new and interesting ways to consume energy. When energy is available, it gets used. Think how much more energy intensive our life is compared to our parents or grandparents. One example – millions of people around the world are starting to adopt and make use of Bitcoin, but the media recently reported that Bitcoin ‘mining’ at various sites around the world collectively consumes more electricity than the Netherlands.
  • Adoption of new technologies can lead to explosive growth in energy services. The internet and all the servers and devices connected to it is one such example. It didn’t really exist thirty years ago, at least not as a consumer service.

Even with significant energy efficiency improvement over time, the Sky 1.5 scenario which is comparable with IPCC P1 to P4 in terms of temperature rise (i.e. 1.5°C), sees final energy demand increasing by 49% in 2050 relative to 2010. The scenario also employs significant sink capacity globally to achieve an outcome of 1.5°C in 2100. The cumulative total across nature based and manmade carbon dioxide removal to 2100 is around 1,000 Gt for Sky 1.5. Plotting this on the chart above, we see that although Sky 1.5 has a similar, but slightly higher final energy demand than P4, it makes less use of sink capacity by about 20%.

Both Sky 1.5 and IPCC P4 demonstrate the considerable sink capacity required for a 1.5°C outcome, unless energy demand can be significantly curtailed in the near term and rapid solutions found and deployed for current hard-to-abate sectors.

Note: Scenarios don’t describe what will happen, or what should happen, rather they explore what could happen. Scenarios are not predictions, strategies or business plans. Please read the full Disclaimer here.

Carbon sinks and reform of the EU ETS

November 19, 2020

On Wednesday morning of this week, POLITICO held a virtual event: “Energy Visions:  Carbon removal and natural sinks in reaching climate neutrality by 2050”.

I was fortunate to have the opportunity to open the event with a few minutes of remarks to set the scene. This was followed by a discussion between the POLITICO moderator and Tina Bru, Norway’s Minister of Petroleum and Energy and then a panel session with;

  • MEP Bas Eickhout, Vice Chair of the Parliament’s Environment Committee and spokesperson for the Greens political group
  • Mauro Petriccione, European Commission Director General for Climate Action
  • Jannicke Gerner Bjerkås, CCS Director at Fortum
  • Gert-Jan Nabuurs, professor European Forest Resources, Wageningen University and Research IPCC Co-ordinating Lead Author

Although the panel couldn’t agree on how to handle the introduction of sinks into the EU as an emissions balancing mechanism, for me at least it is clear that the EU Emissions Trading System offers the simplest route forward. I have also written about this previously. See below for my opening remarks at the POLITICO event.

Good morning.
I want you to imagine for a moment that it is 2050, perhaps your autonomous electric car is already waiting in the driveway to shuttle you to the railway station, and as you step outside the house system shuts off most indoor electricity consumption. On your way to work you start thinking about an event your company had participated in a few days earlier; the last allowance auction under the EU Emissions Trading System. Now that the EU has reached net-zero emissions there would be no further allocation or auctions, in fact no more allowances.
But there is the familiar sound of planes at the nearby airport as the 787 and A350 departures continue, seemingly without pause. Although the first hydrogen fueled Boeing 808 and Airbus A500 planes can now be seen in the skies, a good proportion of air traffic still runs on jet fuel produced from crude oil. Biojet makes up the difference.
The railway station you use is in an industrial part of the city and the cement plant that was constructed there in 2030 using the most efficient process design of the day continues to operate, running on natural gas. It was built to supply concrete foundations for the gigantic 20 MW turbines in the burgeoning wind energy market.
These planes and industrial facilities are part of the 2050 EU landscape and continue to operate but do so in the absence of allowances under the EU Emissions Trading System. How will that be possible?
It is important to recognize that net-zero emissions in 2050 does not represent a point in time when there is no fossil fuel use and therefore no emissions. Today we are 70% dependent on fossil fuels for energy in the EU and although that number is clearly falling, it won’t be zero in 2050. In some cases the technologies required to remove dependence on fossil fuels don’t yet exist or are only at the earliest stages of their development. While some facilities using fossil energy should have carbon capture and storage operating by 2050, that won’t be true in all cases. Planes cannot do this and there will be regions within the EU where local at source carbon capture and storage either isn’t practical or cannot be implemented.
Rather, net-zero represents a balance between remaining emissions and the remote removal of carbon dioxide from the atmosphere. This can be achieved by 2050 in the EU, but we need the policy tools to guide us towards such an outcome. The EU Emissions Trading System is an excellent candidate for change.
Today the Emissions Trading System operates by surrendering allowances against emissions, but when the system ceases to have allowances in 2050, what happens? The Emissions Trading System needs to progress from an allowance-based system to one that manages net-zero emissions by requiring the surrender of sink based units against annual emissions. A sink unit wouldn’t be issued in the way an allowance is but would be created through projects that captured carbon dioxide from the atmosphere and permanently stored it. There are broadly three ways to do this;
One – through industrial projects that strip carbon dioxide from the atmosphere and store it geologically or use it in a way that offers near permanence, such as in making building materials.
Two – through the use of biomass to create energy but capturing and storing the carbon dioxide released in the process, which originated from the atmosphere as the biomass was grown. There is a bio-ethanol plant doing this today in the United States.
And three – by engaging in natural based projects such as rewilding and reforestation, or encouraging farmers to employ different grazing and cultivation techniques which help build soil carbon stocks.
Verified removal units from these types of projects will need to be part of the Emissions Trading System so that some parts of industry and various energy system services can continue operating past 2050. But the change to the trading system needs to be well before 2050, ensuring that enough capacity can be created by incentivising sink activity. A very early milestone would be establishing the certification process for removals within the EU.
Earlier this year Shell released a scenario Sketch illustrating a pathway forward for the EU to reach net-zero emissions by 2050. In that analysis, industrial bioenergy facilities with carbon capture and storage start to operate in the EU by 2035, which points to market signals emerging in the 2020s for project activity to start. We also showed that a gap between what can be achieved and what needs to be achieved for net-zero by 2050 also starts to emerge in 2035. This gap could be filled with nature-based sinks, at least until industrial capacity can catch up, but once again this will require a commercial carbon sink mechanism to incentivise action.
We shouldn’t forget about the period after 2050, at which point the world may require progressive regions such as the EU to extend their reductions into negative territory, in other words having more sinks than emissions. Trading of sinks could be a valuable export opportunity for the EU.
The EU Emissions Trading System is the right commercial lever to drive sink activity forwards, partly because of its carbon pricing structure but also because it must evolve to become a sinks and sources balancing system by 2050. As part of the current rethink of the trading system in preparation for 2030 and beyond, a sink mechanism should be included. Initially this could simply be the recognition of sink units from projects within the EU but should eventually be extended to global recognition of units. These would be transferred under Article 6 of the Paris Agreement along with the necessary safeguards to guarantee environmental integrity and the adjustment of trading partner carbon registries.
Without action in the 2020s to incentivise carbon sinks and subsequent follow-up in the 2030s, the EU may find itself unable to meet its net-zero emissions goal in 2050.
Thank you