Archive for the ‘Climate Science’ Category

Three years ago when Shell released their New Lens Scenarios, the two views of the future looked out far beyond previous scenarios, taking in the period from 2050-2100. This offered the opportunity for both scenarios to explore ways in which the world might reach a point of net-zero carbon dioxide emissions, down from some 40 billion tonnes per annum at the moment. Such an outcome is critically important for the global environment as it means stabilization and then probably some decline in atmospheric carbon dioxide levels, an essential requirement for limiting the current rise in surface temperature.

Net-zero emissions is also a requirement of the Paris Agreement. Article 4 is very clear in that regard, with its call;

“so as to achieve a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of this century. . . “

Energy scenarios typically explore the nearer term and many limit their horizon at 2050, but that isn’t sufficient for seeing truly profound changes in the energy system. These will play out on longer timescales, given the size of the system, the capital and capacity required to turn the system over. Solar energy is a good example. Today, we are in the middle of an apparent boom, but that is founded on years of development and improvement in the underlying technologies, a process that is still underway. Even at current deployment rates, solar still makes up only a small fraction of the global power generation system and electricity only represents 20% of the final energy we actually use. But over many decades, an energy technology such as solar PV may come to dominate the system.

Looking at the emissions issue from the fossil fuel side, even if solar was to dominate, would fossil fuels and the associated emissions of carbon dioxide necessarily decline? Simply building more renewables doesn’t guarantee such an outcome and even a significant reduction in fossil fuel use could still mean a continuing rise in atmospheric carbon dioxide, albeit at a reduced rate. Scenarios help explore such questions and by extending the New Lens Scenarios to 2100, real solutions to reaching net zero emissions present themselves.

The original “New Lens Scenarios” publication from 2013 focussed more on the period through to 2060, but a new publication released by Shell looks specifically at the challenge posed by net zero emissions and explores plausible pathways towards such an outcome using the “New Lens Scenarios” as a backdrop. I have been involved in the development and writing of this publication, which started in earnest only days after the Paris Agreement was adopted. But the material within it comes from the strong base built up over many years through the various Shell scenarios.

The analysis presented sees the energy system doubling in size as global population heads towards 10 billion people. Today we collectively consume about 500 Exajoules of energy; this could rise to some 1000 Exajoules by the end of the century. The makeup of that energy system will most likely look very different from today, but it is probably not a world without fossil energy; rather it is a world with net-zero carbon dioxide emissions. Carbon capture and storage therefore plays a significant role. Even in 2100, hydrocarbon fuels could still make sense for sectors such as aviation, shipping, chemicals and some heavy industry. Electrification of the energy system would need to shifted from ~20% today to over 50% during the century.

NZE Energy mix in 2100
The new supplement is called “A Better Life with a Healthy Planet. Pathways to Net-Zero Emissions”. The title highlights the intersection between the need for energy to meet the UN Sustainable Development Goals and the requirement of the Paris Agreement to reach net-zero emissions. A better life relies on universal access to energy. The publication comes with a wealth of online material to support it.

NZE Cover

Where are we now?

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Last week I presented a simple analysis of the temperature data over the last 50+ years which showed that there was good reason to think that the global surface temperature was rising by about 0.18°C per decade. But a further question to ask is when the current upward trend really started in earnest and therefore where are we today against a baseline of the pre-industrial temperature (i.e. 1850s or thereabouts). This is an important question as we have collectively established a desire to keep warming well below 2°C, but with the real prize being to limit this even further and ideally to 1.5°C.

If the current strong warming trend started in the middle of the last century, say in the post-war boom, then at 0.18°C per decade that results in warming over that period of nearly 1.2°C. The 1950s were also presumably warmer than the 1850s as CO2 levels had risen by some 30 ppm (parts per million) over that period, which argues for the current level of warming to be something more than 1.2°C.

Another way of looking at this is to use the climate sensitivity relationship between cumulative carbon and peak warming, which was estimated at 2°C per trillion tonnes of carbon by Myles Allen and his team in their formative paper published in Nature in 2009. A look at the associated Oxford University website will show cumulative carbon now stands at over 600 billion tonnes, which implies associated warming of about 1.2°C.

Cumulative carbon on June 16th 2016

Yet another way is to seek an answer from a group of climate scientists and I had the opportunity to do just that earlier this week. I am in Boston for the 39th Forum of the MIT Joint Program on the Science and Policy of Global Change. I posed the question and one respondent (Chatham House Rule applies) argued that current warming is around 1.1°C since pre-industrial times, but that there is more to the story than this. The climate system is not at equilibrium, with the oceans still lagging in terms of heat uptake. Therefore, if the current level of carbon dioxide in the atmosphere was maintained at some 400 ppm, the surface temperature would rise by another few tenths of a degree before the system reached an equilibrium plateau. That would take us perilously close, if not over, the 1.5°C goal of the Paris Agreement. This implies that 1.5°C is only possible if we see a fall in atmospheric carbon dioxide, back below 400 ppm; but noting that it is currently rising at 2-3 ppm per annum.

This isn’t to say there are no routes forward to a 1.5°C outcome, with the Joint Program itself publishing one such pathway back in 2012.

MIT Scenarios - Temperature

MIT analysed four pathways that result in different temperature outcomes, including 1.5°C. These are shown in the chart above against a business as usual trajectory based on the 2010 post-Copenhagen national pledges.

  1. An immediate drop to net zero by 2015, starting in 2010 (Natural only after 2015).
  2. A very rapid drop to net zero by 2035, but with growth from 2010 to 2030 (Natural only after 2035).
  3. A more extended drop to net zero by 2060, with the decline commencing in 2010 (Alternative).
  4. The IEA 450 scenario, with emissions peaking around 2020 and reaching net zero by 2070 (IEA 450).

Pathway 3 (Alternative) results in peak warming of just over 2°C, but with a return to 1.5°C by the end of the century. Of the three MIT extreme mitigation scenarios, it also represents an outcome that could at least be envisaged, albeit still very challenging to implement.

The ocean also plays an important role here, but in a different way to that described above. Atmospheric CO2 begins to decline once net zero anthropogenic emissions is reached as the ocean continues to take up significant quantities of CO2 from the atmosphere, but with nothing additional being added from human activities.  This is because the ocean is also lagging in terms of its ability to dissolve CO2. After some 20-30 years, as the ocean’s upper layer comes into balance with the atmosphere, uptake of CO2 slows. The fall in atmospheric CO2 that results also brings down the global surface temperature by about 0.5°C.

However, this scenario required a very sharp decline in emissions from 2010. Current Paris NDC plans show emissions continuing to rise through to 2030 at which point there are good signs of a plateau but by which time atmospheric CO2 may be at 430-440 ppm. The conclusion from all the above; any pathway that eventually delivers 1.5°C is likely to require a fall in atmospheric carbon dioxide back to 400 ppm or even below.

 

A surprise in the data

A recent edition of The Economist featured an article on the current (albeit coming to an end) strong El Nino in the Pacific and the impact or otherwise that a warming climate system might be having on it. The article asks many questions and even delves into the recent controversy about the so-called pause in global warming. The author notes;

The sweltering temperatures in recent months may help settle debates over a supposed “pause” in global warming that occurred between 1998 and 2013. During that period the Earth’s surface temperature rose at a rate of 0.04°C a decade, rather than the 0.18°C increase of the 1990s.

Global temperature data can be challenging to analyse, but one very simple analysis I put together showed quite a surprising result. El Nino events can be categorised, with the events of 1997-98 and 2015-16 both listed as Very Strong. 1972-73 and 1982-83 were also Very Strong events, giving a total of four such events over the last 40 years. Each of these events led to a temperature spike in the global record as reported by the US National Oceanic and Atmospheric Administration (NOAA). The data is as follows;

Screen Shot 2016-06-08 at 21.15.14

A quick plot of this data shows an almost perfect linear trend over recent decades, with the Very Strong El Nino same year global temperature anomaly rising monotonically at 0.18°C per decade. There is no sign of a pause in warming or acceleration, at least over the last 40+ years. Extending the trend into the 2030s indicates that a future Very Strong El Nino event in that period would result in a 1.3°C temperature rise, which is about the equivalent to 1.5°C above pre-industrial levels in the NOAA time series (using late 19th century as a proxy for pre-industrial).

Screen Shot 2016-06-08 at 21.15.30
Casting back a bit further to a much earlier Very Strong El Nino, brings us to 1926. This was reportedly an extreme event for the period and corresponded with the most severe drought in tropical South America during the 20th century. Including it in the chart above as well as a further point in 1963, shows the current linear trend still holding back to 1960, but not into the 1920s. At this time atmospheric carbon dioxide was only just beginning to rise. But the fact that the 1920s El Nino is matched by a presumably elevated 1960s El Nino perhaps points to just how severe that event must have been.

Screen Shot 2016-06-08 at 21.15.43
The data for the last half century for comparable El Nino event years and coinciding with a rise in atmospheric carbon dioxide from 315 ppm to 400 ppm (vs. 275 ppm to 315 ppm over the century before that) indicates that the underlying surface temperature trend is rising consistently, despite the noise associated with year on year fluctuations of the Southern Oscillation (El Nino and La Nina) and other phenomena. This data noise has given rise to claims of both no global warming and accelerating global warming. The reality is sobering enough, even without the histrionics from some observers.

A blast from the past

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We might think of climate change as a phenomenon only reported on by the 21st Century media and imagine that only the people of today are really aware of the risks posed by the rising level of carbon dioxide in the atmosphere. Although the science dates back to the mid to late 19th century, why would anybody of that period take an interest in or even know about the impact that this might have on future generations?

Much to my surprise I recently found that there was interest and from somewhere close to home (for me at least). The clip below comes from a small country newspaper, printed not far from Canberra in Australia in July 1912.

Braidwood

 

COAL CONSUMPTION AFFECTING CLIMATE.

 The furnaces of the world are now burning about 2,000,000,000 tons of coal a year. When this is burned, uniting with oxygen, it adds about 7,000,000,000 tons of carbon dioxide to the atmosphere yearly. This tends to make the air a more effective blanket for the earth and to raise its temperature. The effect may be considerable in a few centuries.

The newspaper in question was the Braidwood Dispatch and Mining Journal, which first appeared on 10 April 1859 and was published twice weekly from 1859 until January 1958. Braidwood was not a big town and was hardly a centre for global studies. A picture of the town centre some twelve years earlier at the turn of the century is shown below.

wallace-st-braidwood

What I find as interesting as the article itself is the fact that it was printed in such a newspaper. This was a small country town yet the newspaper had a science column (Science Notes and News), which is where the snippet comes from. A science column would be hard to find in any newspaper today. Other stories in the same edition talk of a seven thousand foot bore hole drilled in Germany and the revelation that core temperature rises by about 1°C per 100 feet, not to mention the arrival of a skipping machine on the market which turns the rope and records the number of skips.

But perhaps the most interesting question to ponder is where the story came from? Sixteen years earlier Svante Arrhenius had published his paper on the influence of carbonic acid (N.B. Arrhenius refers to carbon dioxide as “carbonic acid” in accordance with the convention at the time he was writing.) in the air upon the temperature of the ground and in it he made mention of the combustion of coal and its release of carbon dioxide into the atmosphere. He wrote more on this in later work. It is unlikely, but not improbable, that the editor of the local newspaper in Australia was busy reading scientific papers by Arrhenius, but the copywriter may have been reading a variety of magazines and publications from which he or she would extract bits and pieces for republication in the Braidwood Dispatch. That means the story probably came from a longer discussion in another journal, but I don’t know which one. It also means that the copywriter thought that the readers of the Dispatch would be interested in this article, which in itself is a revelation.

Arrhenius

 

Going below zero

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With the advent of the Paris Agreement, there is a new focus on net zero emissions. This is largely driven by a better understanding of climate science (the importance of cumulative emissions), but also by a line in the Agreement itself which calls for a ‘balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of this century’. This potentially brings into play a set of technologies known as negative emissions technologies or NETs. A NET is a technology which draws down on atmospheric carbon dioxide; perhaps the simplest implementation of this is planting a tree.

NETs are required for two reasons over the long term;

  1. Be it local or global, a requirement for net zero emissions will inevitably mean a balance between remaining sources of emissions and the removal of carbon dioxide from the atmosphere as an offset, rather than a world of no emissions at all. Remaining sources of emissions could include some continuing use of fossil fuels but without dedicated carbon capture and storage (e.g. aviation) or very difficult to manage emissions such as from the agriculture sector. This requirement may only need NET deployment on a modest scale, simply to match the remaining emission sources. However, if those sources remain significant, then NET deployment would have to be scaled to match.
  2. At a global level, cumulative emissions may have exceeded a desired level for a certain temperature goal, in which case there is a need for an overall drawdown on atmospheric carbon dioxide, beyond that which natural sinks might deliver (e.g. continued ocean uptake). This is likely to require very significant deployment of NETs, certainly on the many gigatonnes per annum scale.

Even before the Paris Agreement, an in-depth look at the IPCC 5th Assessment report would have shown that many of the scenarios consistent with the 2°C goal included a period in the second half of the century when global emissions were negative to achieve a net drawdown on atmospheric carbon dioxide. The reason for needing such a period is that under these scenarios it doesn’t prove possible to limit emissions sufficiently, given the time it takes to re-engineer the energy system in the face of rising demand and legacy infrastructure.

The Paris Agreement has only strengthened the need for negative emissions technologies. With a goal of somewhere between 1.5 and 1.8C (‘well below’, as the Agreement states, could be interpreted as at least 10% below 2°C), the cumulative emissions of carbon should be some 175 billion tonnes of carbon lower than for a 2°C scenario, or 640 billion tonnes CO2. At current levels, that is the equivalent of 15 years emissions. As I illustrated in a pre-Paris post, decades of NET deployment and use may be required to meet this stringent carbon budget.

A recent article in Nature Climate (Biophysical and economic limits to negative CO2 emissions, Nature Climate Vol 6, January 2016) looks more deeply at the set of technologies that society may come to depend on in the coming decades. The article neatly categorises them with yet another set of acronyms (with OU, AS and BC ascribed by me);

  • BECCS: bioenergy with carbon capture and storage.
  • DAC: Direct air capture of carbon dioxide from ambient air by engineered chemical reactions. This would then become DACS (or DACCS) if geological storage were involved.
  • EW: Enhanced weathering of minerals, where natural weathering to remove carbon dioxide from the atmosphere is accelerated and the products stored in soils, or buried deep in land or deep-ocean.
  • AR: Afforestation and reforestation to fix atmospheric carbon ion biomass and soils.
  • OU: manipulation of carbon uptake by the ocean, either biologically or chemically.
  • AS: Altered agricultural practices, such as increased carbon storage in soils.
  • BC: Converting biomass to recalcitrant biochar, for use as a soil amendment.

The article focusses on BECCS, DAC, EW and AR and gives a detailed breakdown of the global impacts of these technology areas in terms of water, energy needs, land use and so on. It is clear that there is no silver bullet to rely on. While BECCS and DAC can potentially be deployed at scale and make a material difference to atmospheric carbon dioxide (>3 GT Carbon per annum by 2100, or 10+ GT CO2), BECCS requires significant land and water use (but is a net energy producer), whereas DAC is a big energy user. The latter is also deemed to be very expensive to implement. EW, on the other hand, just doesn’t make the grade in terms of scale. That leaves AR, which is certainly scalable but only very large scale deployment occupying huge swathes of land will make a significant difference in atmospheric carbon dioxide.

The paper ends with the rather sobering recognition that a failure of NETs to deliver expected mitigation in the future due to any combination of the biophysical and economic limits examined, leaves the world with no ‘Plan B’. Clearly there is much more to be done to commercialise and deliver a sustainable pathway for this family of technologies.

The highlight of the Paris Agreement is without question the ambition embodied within it. This had its foundation with the Alliance of Small Island States (AOSIS) and their deep concern regarding future sea level rise. But the issue snowballed as the conference progressed, supported by a strong dose of techno-optimism that was prevalent throughout the halls of the Le Bourget Conference Centre. The text that was agreed upon is important, with the goal embodied in to distinct sections;

Holding 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;

Parties aim to reach global peaking of greenhouse gas emissions as soon as possible, recognizing that peaking will take longer for developing country Parties, and to undertake rapid reductions thereafter in accordance with best available science, so as to achieve a balance between anthropogenic emissions by sources and removals by sinks of greenhouse gases in the second half of this century . . .

In a post written before the conclusion of COP21, I assessed that a 1.5°C goal would require a rapid forty year transition to net-zero anthropogenic emissions and a period until at least the end of the century with negative emissions via BECCS (bioenergy and CCS) and DACCS (direct air capture and CCS). But the pathway proposed by the Agreement itself isn’t quite as ambitious, even while it aspires to a 1.5+°C outcome. Rather, it proposes achieving a balance between anthropogenic emissions and removals by sinks in the second half of the century. This may not be sufficient to achieve the 1.5+°C goal, with a key deciding element being the role of natural sinks.

The 1.5+°C pathway issue is highlighted in a paper published by the MIT Joint Program in July 2013. MIT deliberately avoided the use of negative emissions technologies, partly due to concerns about their scalability but also preferring to test the impact of natural sinks on the outcome. Of these, the ocean is the major short term sink because of the imbalance between levels of CO2 in the ocean and the atmosphere.

MIT analyzed four pathways that result in net zero anthropogenic emissions. These are shown in the chart below (fossil energy CO2 emissions only) against a business as usual trajectory based on the 2010 post-Copenhagen national pledges.

  1. An immediate drop to net zero by 2015, starting in 2010 (Natural only after 2015).
  2. A very rapid drop to net zero by 2035, but with growth from 2010 to 2030 (Natural only after 2035).
  3. A more extended drop to net zero by 2060, with the decline commencing in 2010 (Alternative).
  4. The IEA 450 scenario, with emissions peaking around 2020 and reaching net zero by 2070 (IEA 450).

MIT Scenarios - CO2 emissions

Pathway 3 is of particular interest. In this case anthropogenic emissions are at net zero by 2060, although starting to decline from 2010 when energy emissions are at 30 Gt CO2 per annum (it is now 2016 and they are at ~33 Gt). This scenario sees temperatures rise above 2°C by mid-century, but then decline as the ocean takes up significant quantities of CO2 from the atmosphere but with nothing being added from anthropogenic sources.  After some 20-30 years, as the ocean’s upper layer comes into balance with the atmosphere, uptake of CO2 slows. Mixing into the deep ocean is much slower but will continue for hundreds to thousands of years.

Back in 2010 the cumulative emissions from 1750 (to 2010) stood at some 532 billion tonnes carbon, which means that Pathway 3 approximates a 1.5°C outlook as the area under the curve from 2010 to 2060 (energy, cement and land use) represents an additional 250 billion tonnes of carbon emissions, giving a total of some 780 billion tonnes. The relationship between carbon emissions and temperature is about 2°C per trillion tonnes. The chart below shows the modelled pathway which results in an end-of-century temperature rise of 1.5°C.

MIT Scenarios - Temperature

The natural sink is therefore very important, offering some 0.5°C (see the light blue line in the chart above) of temperature reduction following an overshoot. This is possibly the only way in which 1.5°C can be met,  although significant anthropogenic sinks may also be developed (including reforestation) later which could offer the same drawdown. As such, with the Paris Agreement potentially not making use of this and instead only providing for emissions to fall to a level which matches the ability of sinks to take up carbon emissions, the task of meeting 1.5°C becomes considerably more difficult.

The same is true of the IEA 450 Scenario. With 2010 now behind us, the future equivalent of the Alternative pathway which saw reductions from 2010 onwards is probably the red 450 line (reductions from 2020), which overshoots to 2.7°C before achieving something of a plateau at 2°C. But to bring this down further by the end of the century and therefore comply with the Paris Agreement would also require the major application of anthropogenic sinks, such as via CCS and rapid reforestation.

This discussion may be something of a moot point today because the job of rapidly reducing emissions hasn’t even started and arguably we have at least 40+ years to think about where the endpoint should be. Nevertheless, as nations begin to reflect on the Paris outcome in the coming months and relook at their respective reduction pathways, the long term end point does become relevant because energy infrastructure planning requires a multi-decadal outlook. In its initial formulation of a long term carbon budget, the UK did need to look forward to 2050 but that was from a 2008 starting point. With a new starting point of 2020 or thereabouts, a 2060 or even 2070 end-point may well be considered.

There is of course a disturbing flip side to this story – continued rapid uptake of CO2 by the ocean also gives rise to increasing levels of ocean acidification.

COP21: A Pathway for 1.5°C

The case for limiting the rise in global temperatures to 2°C was made many years ago and finally agreed at COP16 in Cancun in 2010. But the text noted the importance of an even more aggressive target, notably 1.5°C, proposed by the small island states who were deeply concerned about future sea level rise. While 1.5°C doesn’t guarantee to limit sea level rise such that certain island nations remain safe, it does further shift the global risk profile in terms of possible major changes in the ice shelves.

The idea of a 1.5°C goal has remained largely in the background since 2010, but COP21 has brought the issue to the forefront of negotiators minds, with a reported group of some 100 countries now willing to support such an objective. At a reception early in the second week, the UK Climate Minister was very upbeat about the 1.5°C goal and the government’s role in working with AOSIS (Alliance of Small Island States). At the COP Plenary on Wednesday night (9th December), many groups and nations spoke about the need for a 1.5°C goal.  But while there is increasing enthusiasm for and talk about such a goal, there seems to be limited substantive discussion on the feasibility of achieving it.

As often discussed in my postings, the expected global temperature rise is closely linked with cumulative emissions over time, not the level of emissions in a certain year. This means that what might have seemed achievable in 2010, is all the more difficult in 2015 with higher emissions and continued upward pressure. In fact, between 2010 and 2015 another 60 billion tonnes of carbon has been released into the atmosphere. Total emissions since 1750 now stand at just under 600 billion tonnes carbon, with 1.5°C equivalent to some 750 billion tonnes carbon based on a climate sensitivity of 2°C per trillion tonnes. Even if emissions were to continue to plateau as we have seen over 2014-2015, the 1.5°C threshold would be reached as early as 2028.

There are always a variety of trajectories possible for any temperature goal, but 1.5°C offers little room for flexibility, given its stringency. One such pathway which adds up to ~750 billion tonnes carbon by 2100 is shown below (global CO2 emissions on the vertical scale). In this pathway, global net zero emissions must be reached in just 40 years (860 billion tonnes accumulation), followed by another half century of atmospheric carbon removal and storage (~100 billion tonnes removal). Some 10 billion tonnes of CO2 must be removed and stored each year by late in the century, either through bio-energy with carbon capture and storage (BECCS) or direct air capture of CO2 and subsequent storage (DACCS). Significant reforestation would also play a major role. With infrastructure in place, the 22nd century might even offer the possibility of drawing down on CO2 below a level that corresponds with 1.5°C.

OnepointfiveC

Apart from massive reliance on CCS both on the way to net zero emissions and afterwards to correct the over accumulation, such a plan would require a complete rebuild of the energy system in just 40 years. This would include the entire industrial system, all transport and power generation. Alternatives would have to be found for many petroleum based products and a new large scale synthetic hydrocarbon industry would be needed for sectors such as aviation and shipping. While agriculture is largely a bio based emissions system, a solution to agricultural methane emissions would also nevertheless be needed.

A pathway that doesn’t involve future use of CCS would require net zero emissions in just 23 years – an option that isn’t even remotely feasible. Returning to the 40 year pathway, even this presents an immensely challenging task. While it might be feasible to have a zero emissions power sector in under 40 years, particularly given that all the necessary technologies to do so exist in one form or another, electricity still represents only 20% of final energy use. Solutions would have to be found for all other sectors, which in many instances involves electrification and therefore places a significant additional load on the redevelopment of the power generation system. Aviation would be particularly tricky.

Finally, there is CCS itself. The pathway above (and almost any other 1.5°C pathway) is completely dependent on it, yet the technology is hardly deployed today. It is certainly commercially ready, but the barriers to deployment are many, ranging from the lack of an economic case for project development to public concern about deep storage of carbon dioxide. The later that net zero emissions is reached, the greater the post net zero dependence on CCS becomes.

While the case for 1.5°C has certainly been made from a climate perspective, it has yet to be demonstrated from an implementation perspective.

COP21: Targets, goals and objectives

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As the negotiators struggle on in Paris at COP21, the question of the long term goal has emerged. What should it be, how should it be structured and will it send the necessary signal to drive future national contributions.

The idea of a goal goes back to the creation of the UNFCCC. There is the original text agreed when the Convention was first written in 1992, i.e. “. . . stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system . . . “. At COP16 in Cancun, the Parties to the UNFCCC reformulated this as a numerical goal; the need to limit warming of the climate system to no more than 2°C above the pre-industrial level with consideration for reducing this to 1.5°C as the science might dictate. This seems very clear, but in fact offers little immediate guidance to those attempting to establish a national or even global emissions pathway.

The climate system is a slow lumbering beast and the global temperature could take years or even decades to settle down once there is stabilization of carbon dioxide (and other greenhouse gases) in the atmosphere. It could be decades after that before we are collectively sure that no further temperature rises will take place. But the science has shown that the eventual rise in temperature is strongly related to the cumulative emissions of carbon dioxide over time, starting when emissions were negligible (say 1750) and running through several centuries (e.g. to 2500). Myles Allen et. al. from Oxford University equated 2°C to the cumulative release of one trillion tonnes of carbon, which offers a far more mechanistic approach to calculating the point at which 2°C is reached. So far, cumulative emissions amount to some 600 billion tonnes of carbon. However, even this approach has uncertainty associated with it in that the actual relationship between cumulative emissions and temperature is not precisely known. If emissions stopped today, it is very unlikely (but not a zero chance) that warming would continue to above 2°C, but if emissions were to stop when the trillion tonne threshold is reached then there is only a 50% chance that the temperature would stay below 2°C. The agreement in Cancun doesn’t cover uncertainty.

The Oxford University team have developed a website that counts carbon emissions in a bid to familiarize people with the concept. As of writing this post, it was counting through 596 billion tonnes and provided an estimate that 1 trillion tonnes will be reached in October 2038. The INDCs already reach out to 2030 and as they stand, will not put the necessary dent into the global emissions profile that is needed to avoid passing one trillion tonnes. In terms of energy system development, 2038 is in the medium term. Most forecasts out to this period, including the IEA New Policies Scenario which factor in the INDCs, show energy demand and emissions rising over that period, not falling.

In line with the Cancun Agreement, a number of Parties have maintained the need to lower the goal to 1.5°C, but particularly those from low lying island states who are justifiably concerned about long term sea level rise. This goal is being voiced more loudly here in Paris. Using the relationship developed by Allen et. al., this implies that 1.5°C would be exceeded if cumulative carbon emissions passed 750 billion tonnes, which could happen as early as 2027. This would imply a massive need for atmospheric CO2 capture and storage over the balance of the century for the simple reason that cumulative emissions could not be contained to such a level by energy system reductions alone.

More recently the concept of net zero emissions (NZE) has emerged. This is the point in time at which there is no net flow of anthropogenic carbon dioxide into the atmosphere; either because there are no emissions at all or if emissions remain because they are completely offset with a similar uptake through carbon capture and storage or reforestation and soil management. Emissions are likely to remain for a very long time in sectors such as heavy transport, industry and agriculture. NZE has been closely linked to 2°C, but in fact any temperature plateau, be it 1.5°C or even 4°C requires NZE. If not, warming just continues as atmospheric CO2 levels rise. There is now a discussion as to when NZE should be reached – as early as 2050 (but practicality must be a consideration), or perhaps by the end of the century. However, what is actually important is the area under the emissions curve before NZE is achieved, less the area under the curve after it is reached, assuming emissions trend into negative territory with technologies such as direct air capture or bioenergy with carbon capture and storage (DACCS or BECCS). The date at which NZE is reached is important, but not necessarily an indicator of the eventual rise in temperature. Just to complicate matters further, although the world needs to achieve NZE eventually, it may be the case that net anthropogenic emissions do not have to be zero by 2050 or 2100 to meet the 2°C  goal because of carbon removal arising from natural sinks in the oceans and terrestrial ecosystems.

Other proposals put forward by Parties and some observers simply call for an urgent peaking of emissions. This is important as well, but again it doesn’t tell the full story. What happens after the emissions peak is critical. A long slow decline to some plateau would be positive, but unless that plateau is close to NZE, then cumulative emissions continue to build, along with the associated warming. Other proposals argue for emissions to be at some reduced level by 2050, which presumes a certain follow-on trajectory equating to 2°C or thereabouts.

Where the Parties land in this discussion remains to be seen, but with only days left and the complexity of goal setting becoming apparent, this may end up being an issue for the years ahead rather than one that can be fully resolved in Paris in a week. 2°C may have to do for now.

Emission pathway

 

As COP21 starts and the negotiators face the task of reaching an agreement, one of the most important points of discussion will be the review and recalibration of INDCs. Many organisations, including some business based ones (i.e. We Mean Business), are arguing for a five yearly review of the national contributions. If strictly adopted, this might mean that the first round of INDCs are already under review before they formally commence (i.e. 2020), such that the global emissions outcome by 2025 is already lower than current INDC projections would project. An alternative is a 10 year review, such that the first deviation from current INDC projections becomes apparent in the early 2030s.

There are practical considerations associated with this. Many who view the energy industry from the outside have consistently had expectations for rapid change. For example, the UNFCCC itself has continued with its pre-2020 workstream even as the time for meaningful change has diminished. This isn’t to argue that nothing can happen between now and 2020, but it is unlikely that much extra can now happen in that time frame. The energy industry is built on long lead times, project cycles that can stretch out to a decade and capital cycles that are often laid out years in advance of actual spending. Sometimes this can be disrupted, particularly when there is a sudden shift in market price structure, but that is not the normal pattern of change.

There is also the reality of policy development timelines needed to trigger change. For example, the EU is in the midst of a three year (at least) examination of the climate and energy needs for the period 2020 to 2030, which requires green papers, white papers, various stakeholder consultations, draft legislation, parliamentary committee discussion, a parliamentary vote, Member State agreement and transfer to national legislation. It is unlikely that this would be revised as soon as 2018-2021 having just reached agreement on the entire package in 2016 and finalised EU wide adoption in 2017. The institutional capacity may not exist for constant revision.

But there is an overriding thought which should take priority – the emissions and therefore eventual temperature impact of moving to a more aggressive review timetable. It is very clear that the current round of INDCs do not deliver a 2°C pathway – many analysts and the UNFCCC have concluded that. The INDCs also say little to nothing about the past 2030 period, so future INDCs or review of current INDCs will be needed.

A relatively basic analysis can give some insight as to the climate value of review and the benefit of conducting that on a five year basis or a ten year timetable. I put this together as outlined below;

  • There isn’t really a clear emissions trajectory for the current round of INDCs, at least not after 2030. For the purposes of this analysis I have assumed that they result in peaking of global emissions in the 2030s, followed by the beginnings of a decline to 2040 and beyond. Some would argue that even this is optimistic.
  • The 2°C pathway reaches net-zero emissions in about 2080, then enters a period of negative emissions through the use of a technology such as BECCS (biomass energy with carbon capture and storage).
  • In the case of a five year correction process, I assumed that every five years the UNFCCC looks at progress against a 2°C pathway (which of course will change over time, but I haven’t got into that detail) and after each new round of submissions the INDC pathway, as it would be at that point in time, shifts a quarter of the way further towards the 2°C pathway. The result is an emissions trajectory that starts to deviate from the current INDC pathway by 2025.
  • In the case of the ten year correction process, the same happens but on a ten year cycle, with the intervening five year period declining at the same rate as the previous five year period. Because of the slower turnaround in the process, I also assumed that after a more protracted INDC discussion, the shift in the pathway is relative to the 2°C line as it was five years earlier, rather than at the time. As such, there is a bit more lag built into the process and emissions remain the same as the current INDC pathway until after 2030.

INDC Review Pathways

  • The chart above shows the four potential pathways; 2°C, the current INDCs extended out for several decades and the corrected pathways, based on five year and ten year correction cycles.

As shown, the uncorrected INDC pathway is a 3+°C scenario, whereas both the five year and ten year correction pathways are about 2.5°C and both arrive at a net zero emissions outcome around the turn of the century. As such, it is clear that a review cycle can change everything and has the potential to deliver a clear outcome rather than an open ended emissions tail stretching well into the 22nd century.

But the difference between them is 0.15°C, or a cumulative 280 million tonnes of CO2 over the balance of the century. While this is not insignificant, the more important goal for the negotiators should be to agree a clear review and recalibration process, rather than be too focussed on the precise timeliness of it.

One million tonnes of CO2

The first week of November sees Shell officially open its first major carbon capture and storage (CCS) facility, the Quest project. It is in Alberta, Canada and will capture and store about one million tonnes of carbon dioxide per annum. Construction commenced back in September 2012 when the Final Investment Decision (FID) was taken and the plant started up and began operating for the first time in September of this year, just three years later. It is one of only a handful of fully integrated carbon capture and storage facilities operating globally. There are now many facilities that capture CO2 but mainly linked to Enhanced Oil Recovery which provides an income source for these projects.  Quest has dedicated CO2 storage, developed in an area some 65 kms from the capture site at a depth of about 2 kms.

Quest Construction

The Quest income source is not based on EOR; it has been able to take advantage of the government implemented carbon price that prevails within Alberta. Although the current carbon pricing mechanism has an effective ceiling of $15 per tonne CO2 which isn’t sufficient for CCS, let alone a first of its kind, it nevertheless provides a valuable incentive income to operate the facility which has been built on the back of two substantial capital grants from the Provincial and Federal governments respectively. A supplementary mechanism also in place in Alberta provide credits related to the carbon price mechanism for the early years of a CCS project, providing additional operating revenue for any new facility.

Canada, as it turns out, has become a global leader in CCS. The Quest facility is the second major project to be started up in Canada is as many years, with the Saskpower Boundary Dam project commencing operations this time last year.

As noted, Quest will capture and store approximately one million tonnes of carbon dioxide per annum. It demonstrates how quickly and efficiently large scale CO2 management can be implemented once the fiscal conditions are in place. Quest, which is relatively small in scale for an industry that is used to managing gas processing and transport in the hundreds of millions to billions of tonnes globally, demonstrates both the need for continued expansion of the CCS industry and the importance of carbon pricing policy to drive it forward. This single facility far surpasses the largest solar PV facilities operating around the world in terms of CO2 management. Take for example the Desert Sunlight Solar Farm in California, currently the fourth largest solar PV power station in the world. According to First Solar, it displaces 300,000 tonnes of CO2 annually, less than a third of that captured and permanently stored by Quest.

A key difference though is the use of the word displace. Alternative energy projects don’t directly manage CO2, they generate energy without CO2 emissions. But, as I have noted in previous postings and in my first book, the release of fossil carbon to the atmosphere is more a function of energy prices and resource availability. This means that even when a project like Desert Sunlight operates, the CO2 it notionally displaces may still be released at some other location or at some other time, depending on long term energy prices and extraction economics. There is no doubt that the CO2 is not being emitted right now in California, but that doesn’t necessarily resolve the problem. Quest, by contrast, directly manages the CO2 from fossil fuel extraction.

The requirement to provide alternative energy (i.e. without CO2 emissions) needs to grow, but we shouldn’t imagine that such action, by itself, will fully resolve the climate issue. That will come through the application of carbon pricing mechanisms by governments, driving the further expansion of both the alternative energy and CCS industries as a result.

A video about the Quest project, made by the constructors, Fluor, is available here.