Archive for the ‘Climate Science’ Category

Getting to net-zero emissions

It is looking increasingly likely, but not a given, that a reference to global net-zero emissions or even a specific goal to achieve net-zero emissions by a certain date (e.g. end of the century) will appear in the climate deal that is expected to emerge from the Paris COP at the end of this year. But like many such goals, it is both open to interpretation and raises questions as to how it might actually be achieved.

The background to this is that the issue itself implies that this outcome is necessary. The IPCC says in its 5th Assessment Report;

Cumulative emissions of CO2 largely determine global mean surface warming by the late 21st century and beyond. Limiting risks across RFCs (Reasons for Concern) would imply a limit for cumulative emissions of CO2. Such a limit would require that global net emissions of CO2 eventually decrease to zero and would constrain annual emissions over the next few decades (Figure SPM.10) (high confidence).

However, the term net-zero needs some sort of definition, although this is currently missing from the UNFCCC text. One online source offers the following;

Net phase out of GHG emissions means that anthropogenic emissions of greenhouse gases to the atmosphere decrease to a level equal to or smaller than anthropogenic removals of greenhouse gases from the atmosphere.

The above effectively means stabilization of the atmospheric concentration of CO2, which also aligns with the ultimate aim of the UNFCCC Convention (stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system). This could still leave room for some level of emissions in that climate models show atmospheric concentration of carbon dioxide will decline if anthropogenic emissions abruptly stopped. In a 450 – 500 ppm stabilization scenario emissions could remain in the range 7-10 billion tonnes CO2 per annum without driving the atmospheric concentration higher. This is far below current levels (35 billion tonnes per annum from the energy system alone), but it isn’t zero. It can be classified as net-zero though, in that the atmospheric concentration isn’t rising.

However, such an outcome, while stabilizing the atmospheric concentration may not be sufficient to prevent dangerous interference with the climate system. In that case an even lower level of emissions may be required, such that atmospheric concentrations do begin to fall and stabilize at a lower concentration.

Another definition of net-zero may simply apply to anthropogenic emissions directly, irrespective of what the concentration in the atmosphere might be doing. In this case, any remaining emissions from anthropogenic sources (and there will be some) would have to be offset with sequestration of carbon dioxide, either via CCS or a permanent forestry solution. In the CCS case, the carbon dioxide would need to come from a bio-source, such as the combustion of biomass in a power station. This is what the IPCC have termed BECCS.

A final step which goes beyond net-zero, is to have an anthropogenic net-negative emissions situation, which is drawing down on the level of carbon dioxide in the atmosphere through some anthropogenic process. This would be necessary to rapidly lower the concentration of carbon dioxide in the case of a significantly elevated level that comes about in the intervening years between now and the point at which the concentration stabilizes. Very large scale deployment of BECCS or an atmospheric capture solution with CCS would be required to achieve this.

Finally, there is the consideration that needs to be given to greenhouse gases other than carbon dioxide. Methane for example, while a potent greenhouse gas, is relatively short lived (a decade) in the atmosphere so will require some thought. Even in a zero energy emissions system, methane from agriculture and cattle will doubtless remain a problem.

Both of the Shell New Lens scenarios end in a  net zero emissions outcome by the end of the century, but this is within the energy system itself and does not encompass the full range of other sources of CO2 emissions and other long lived greenhouse gases. Nevertheless, with extensive deployment of CCS the Mountains scenario heads into negative emissions territory by 2100 and the Oceans scenario soon after that (which means there is potential to offset remaining emissions from very difficult to manage sources). Oceans relies on this approach in a major way to even approach zero in the first instance

Many look to renewable energy as a quick solution to the emissions issue, but the reality is far more complex. While we can imagine a power generation system that is at near zero emissions, made up of nuclear, renewables and fossil fuels with CCS, this is far from a complete solution. Electricity currently represents only 20% of the global final energy mix (see below, click for a larger image: Source IEA).

Global final energy 2012

Solutions will need to be found for a broad range of goods and services that give rise to greenhouse gas emissions, including non-energy sources such as limestone calcination for cement and cattle rearing for dairy and direct consumption. While we can also imagine a significant amount of global light transport migrating to electricity, shipping, heavy transport and aviation will not be so simple. Aviation in particular has no immediate solution other than through a biofuel route although there is some experimentation underway using high intensity solar to provide the energy for synthesis gas manufacture (from carbon dioxide and water), which is then converted to jet fuel via the well-established Fischer–Tropsch process. There are also dozens of industrial processes that rely on furnaces and high temperatures, typically powered by fuels such as natural gas. Metal smelting currently uses coal as the reducing agent, so a carbon based fuel is intrinsic to the process. Solutions will be required for all of these.

Whether we aim for a very low level of emissions, true net-zero anthropogenic emissions or negative emissions is somewhat academic today, given the current level of emissions. All the aforementioned outcomes are going to require a radical re-engineering of the energy system in a relatively short amount of time (< 80 years).

Talking about climate change

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From the rarefied atmosphere of the Swiss Alps to a small London theatre, there has been a lot said about climate change over the last couple of weeks.

The World Economic Forum held its annual retreat at Davos, with climate change high on the agenda. Much of the discussion was about building additional momentum towards a UNFCCC led agreement in Paris at the end of this year. Business leaders, politicians and other prominent people from civil society reiterated the need for a strong outcome. World Bank President Jim Yong Kim was more specific and called on leaders to “break out of the small steps of business as usual and provide that structure, first and foremost by putting a price on carbon”. The call for more emphasis on carbon pricing has been a strong World Bank theme for a year now.

While there was good talk emanating from Davos, in Brussels the scene was very different. The EU Parliament ITRE Committee (Industry, Research and Energy) was apparently not listening to the calls from Davos and instead ended up with “no opinion” on the important proposals required to support the carbon price delivered by the EU ETS, through the early implementation of the proposed Market Stability Reserve (MSR). The “no opinion” outcome was the result of not supporting the need to start the MSR early and use the 900 million backloaded allowances as a first fill, but then rejecting an alternative proposal on how the MSR should be taken forward. The only silver lining in this otherwise dim cloud is that the debate is about the proposed structure of the MSR, rather than whether an MSR should be present at all. Nevertheless, it is disappointing that some industry and business groups in Brussels did not seem aligned with the recognition that many of their member CEOs were giving to the carbon pricing discussion in Davos just a few hundred miles away.  The proposals for the MSR now have to go to the important ENVI (Environment) Committee in Parliament as well as to the Member States, where there is cause for optimism that they will adopt a position in favour of a stronger MSR reform.

One business group did give very strong support to the MSR proposals, the UK and EU based Corporate Leaders Group (CLG). This organisation started its life 10 years ago, which means it is also celebrating a landmark birthday along with the EU ETS. The CLG sits under the Cambridge University Institute for Sustainability Leadership, with the Prince of Wales as its patron. This is a group that has been talking about the need for a robust carbon price in the EU for many years and backing that talk up with strong advocacy in Brussels and various Member State capitals. Birthday celebrations were held in London to mark the occasion, with the Prince of Wales in attendance. The CLG was a step ahead of the World Bank with its own Carbon Price Communique back in 2012. While the World Bank effort has garnered greater support than the original CLG effort, it is worthy of recognition that the current push for this important instrument had its roots in the business community.

Despite the important talk in Brussels and Davos, the real talk on climate change came from a small theatre in Sloan Square, London. Climate change might seem like an odd subject for the London theatre scene, but nevertheless there it was. Chris Rapley, former head of the British Antarctic Survey, more recently the head of the Science Museum and now Professor of Climate Science at University College London, staged an engaging one man show to talk about the climate. This wasn’t the Inconvenient Truth with its high profile narrator and 200 odd PowerPoint slides, but more a fireside chat about paleo-history, the atmosphere, trace gases and the global heat balance. Here was a man who had spent the majority of his life studying this issue, from field measurements in Antarctica to computer analysis of satellite observations and his message was very clear; we are in trouble. There was no alarm, no hysteria and no predictions of an apocalypse, but just a softly spoken physicist explaining his job and describing with great clarity what he had learned over the course of some forty years of hard work. The audience was engrossed by the monologue and the gently changing backdrop of graphs and charts that seemed to envelop the speaker.

Chris Rapley 2071

This production is a unique approach to communicating the climate change issue to a new audience. It is small in scale, but it will get people thinking about the subject and hopefully discussing it in less partisan terms. The show, 2071, has now completed a second short run in London but may be destined for some other venues. I would highly recommend it.

The global energy system works on timescales of decades rather years. When considering the changes required in managing the climate issue, the short to medium term takes us to 2050 and the long term is 2100! As such, drawing long term conclusions based on a 2050 outlook raises validity issues.

A new Letter published in Nature (and reported on here) discusses the long term use of fossil fuels, further exploring the notion that certain reserves of oil, gas and coal should not be extracted and used due to concerns about rising levels of CO2 in the atmosphere. But the analysis only looks to 2050 in its attempt to quantify which reserves might be more penalised than others, assuming we are in a world that is actually delivering on the goal of limiting warming to 2°C. The authors drew on available data to establish global reserves at 1,294 billion barrels of oil, 192 trillion cubic metres of gas, 728 Gt of hard coal and 276 Gt of lignite. These reserves would result in ~2,900 Gt of CO2 if combusted unabated, with approximately two thirds of this coming from the hard coal alone.

The Letter draws on the original work of Malte Meinshausen, Myles R. Allen et. al. which determined that peak CO2 induced warming was largely linked to the cumulative release of fossil carbon to the atmosphere over time, rather than emission levels at any particular point in time. They determined that surpassing the 2°C global goal could be quantified as equivalent to the release of more than 1 trillion tonnes of carbon (3.7 trillion tonnes CO2), with their timeframe being 1750 (i.e. the start of the modern use of coal) to some distant point in the future, in their case 2500. Precisely when CO2 is released within this timeframe is largely irrelevant to the outcome, but very relevant to the problem in that the continued release of carbon over time, even at much lower levels than today, eventually leads to an accumulation with the same 2°C or higher outcome (the slow running tap into the bathtub problem). Hence, the original work gives rise to the sobering conclusion that net-zero emissions must be a long term societal goal, irrespective of whether the whole issue can be limited to 2°C. “Net-zero” language has now appeared as an optional paragraph in early drafting text for the anticipated global climate deal currently under negotiation.

As a point of reference, the associated Trillionth Tonne website shows the cumulative release to date (January 2015) as 587 billion tonnes of carbon, which leaves 413 billion tonnes (~1.5 trillion tonnes CO2) if the 2°C is not to be breached (on the basis of their midrange climate sensitivity). The chart below is extracted from the original Meinshausen / Allen paper and illustrates the relationship, together with the inherent uncertainty from various climate models.

Peak warming vs cumulative carbon
Further work was done on this by Meinshausen et. al. They attempted to quantify what the results mean in terms of shorter term greenhouse gas emission targets, which after all is what the UNFCCC negotiators might be interested in. While the overarching trillion tonne relationship remains, it was found;

. . . .that a range of 2,050–2,100 Gt CO2 emissions from year 2000 onwards cause a most likely CO2-induced warming of 2°C: in the idealized scenarios they consider that meet this criterion, between 1,550 and 1,950 Gt CO2 are emitted over the years 2000 to 2049.

This focus on a cumulative emissions limit for the period from 2000 to 2049 (which is arguably a period of interest for negotiators) has been picked up by the most recent Letter and it is the starting point for the analysis they present, although slightly refined to 2011 to 2050. The Letter has concluded that;

It has been estimated that to have at least a 50 per cent chance of keeping warming below 2°C throughout the twenty-first century, the cumulative carbon emissions between 2011 and 2050 need to be limited to around 1,100 gigatonnes of carbon dioxide (Gt CO2). However, the greenhouse gas emissions contained in present estimates of global fossil fuel reserves are around three times higher than this and so the unabated use of all current fossil fuel reserves is incompatible with a warming limit of 2°C. . . . . Our results suggest that, globally, a third of oil reserves, half of gas reserves and over 80 per cent of current coal reserves should remain unused from 2010 to 2050 in order to meet the target of 2°C.

Further to this, the Letter also deals with the application of carbon capture and storage (CCS) for mitigation and finds that;

Because of the expense of CCS, its relatively late date of introduction (2025), and the assumed maximum rate at which it can be built, CCS has a relatively modest effect on the overall levels of fossil fuel that can be produced before 2050 in a 2°C scenario.

The choice of 2050 is somewhat arbitrary, in that while it may be important for the negotiating process, it is largely irrelevant for the atmosphere. But running a line through the middle of the century and drawing long term conclusions on that basis does change the nature of the issue and potentially leads to high level findings that are linked to the selection of the line, rather than the science itself. Most notable of these is the finding regarding the use of oil, coal, and gas reserves up to 2050 rather than their use over the century as a whole.

The study notes that current global reserves of coal, oil and gas equate to the release of nearly 3 trillion tonnes of CO2 when used and based on this draws the conclusion that two thirds of this cannot be consumed if a global budget were in place that limits emissions to 1.1 trillion tonnes of CO2 for the period 2011 to 2050. The problem here is that the current reserves are unlikely to be consumed before 2050 anyway. The Shell New lens Scenarios contrast a high natural gas future with a high renewable energy future, but in both cases the unabated CO2 (i.e. before the application of CCS) released from energy use over the period 2011-2050 is about 1.6 trillion tonnes. Using this as a baseline reference point for the period to 2050 rather than total global reserves, would then lead to a different conclusion and a much lower fraction that cannot be used. In the case of the Shell Mountains scenario which has both lower unabated CO2 (high natural gas use) and high CCS deployment, the net release of CO2 from energy use over the period 2011-2050 is about 1.5 trillion tonnes. Of course we should add the other sources of CO2 (i.e. cement and land use change) to this for a complete analysis and also recognise that neither of the New Lens scenarios can resolve the climate issue within the 2°C goal (discussed in an earlier post here), but both are close to net-zero emissions by the end of the century.

Looking out to the end of the century also changes the findings with regards the application of CCS. Any energy technology, be it solar PV or CCS, will take several decades to reach a scale where it substantively impacts the energy system. During that build up period, its impact will therefore be modest and this is the observation made in the Nature Letter. But by 2050 CCS deployment could be substantial and in the Mountains scenario CCS reaches its peak by the end of the 2050s decade. Therefore, it is the use of CCS after 2050 that really impacts the total use of fossil fuels this century. From 2050 to 2100 net fossil fuel emissions in Mountains are ~560 billion tonnes CO2, far less than the period 2011-2050 and similar in scale to a post 2050 “budget” that would be remaining in a world that limited itself to 1 trillion tonnes CO2 over the period 2011-2050 (i.e. for a total of 1.5 trillion tonnes as noted above).

With such CCS infrastructure in place and given the size of the remaining ultimately recoverable resources (which the Letter puts at ~4,000 Gt for coal alone), fossil fuel use could continue into the 22nd Century hardly impacting the level of CO2 in the atmosphere, assuming it remains competitive with the alternatives available at that time. CCS in combination with biomass use, also offers the future possibility of drawdown on atmospheric CO2.

The big challenge is the near term, when fossil fuel use is meeting the majority of energy demand, alternatives are not in place to fill the gap and CCS is not sufficiently at scale to make a truly material difference. Of course if CCS scale up doesn’t start soon, then the long term becomes the near term and the problem just gets worse.

Two views on mitigation economics

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The annual Forum held by the MIT Joint Program on the Science and Policy of Global Change is always an interesting event, with excellent presentations and lively debate ensuing. The recent Forum held in Boston in early October was no exception thanks to a discussion on two very different approaches to triggering the necessary mitigation of carbon dioxide emissions.

The debate started with a presentation on cumulative emissions and the clear link to atmospheric warming. This comes back to the “stock” vs. “flow” nature of carbon dioxide into the atmosphere which I have written about here and is the foundation of my recent book. The key to the issue is that as CO2 is a stock addition to the atmosphere, it doesn’t matter when or where the CO2 is emitted for the same net accumulation. As a result, the eventual accumulation will tend towards the full release of known fossil fuel reserves simply because the infrastructure exists to extract them and as such they will get used somewhere or at some time.  This also implies only one remaining path forward (given that non-use is unlikely) for stabilizing atmospheric concentrations of CO2; capturing and storing the CO2 when the fuels are used (i.e. Carbon Capture and Storage or CCS)

The above line of reasoning led one participant to propose that the simplest solution to the climate issue was to mandate sequestration, starting with a small amount for each tonne of CO2 emitted, say 1-2%, but progressively increasing this throughout the century until 100% is reached. Tradable CCS certificates (where one certificate represents one tonne of CO2 stored) could be used to distribute the benefits of individual large projects amongst many, particularly in the early years when the sequestration requirement from an individual emitter would still be small. Further, it was argued that this was economically more attractive than the widespread use of a carbon price, which would have to get to higher levels (probably more than $50/tonne) than current systems are offering to trigger even the first CCS project.

In the case of CCS certificate trading, which might trade in the range $50-$100 per tonne of stored CO2 early on, the cost for an individual emitter would nevertheless be initially small. If this was started in 2020 at 1% and reached 15% sequestration by 2030 (i.e. 100% by mid 2080s), the average cost over the period 2020-2030 to an emitter would be $8.50 per tonne of CO2, even with CCS certificates trading at $100 each. This is about the current level of the EU ETS which of course is unlikely to see any CCS projects at such prices.

For a carbon pricing approach, the CO2 price would have to be somewhat higher than the current level in the EU ETS to trigger CCS activity, which would likely delay its implementation and in any case probably cause grief within the system simply because of the higher price and its claimed impact on industry, competitiveness and consumers. It was argued in the MIT debate that this latter effect could well mean that it becomes politically unacceptable to ever let direct pricing mechanisms get to the level required for CCS.

The carbon pricing economists in the room responded to this, arguing that the direct pricing approach was more efficient in that it would allow a range of other mitigation options to play out in the interim before CCS was actually needed. This brought the response that only under the circumstances of uniform carbon pricing with full global reach might this be true; although with the caveat that in the context of an accumulation problem, there were no other mitigation options other than CCS and not using the fuels in the first instance. Partial reach (e.g. the EU ETS and China ETS) of carbon pricing, while significant, might simply introduce a trade distortion, rerouting fossil fuels to other parts of the world and eventually resulting in the same accumulation in the atmosphere. The claim was that carbon pricing tended to address the problem on a flow basis rather than stock basis and measured success as reduced emssions in the location where it operated, rather than reduced accumulation in the atmosphere over the long term. By contrast, it was argued that any application of CCS, even on a local basis, dealt directly with accumulation.

There wasn’t a resolution to the issues discussed above, but the discussion was a great example of the early development of policy thinking. Carbon pricing has dominated the debate for many years and rightly so, but as the science shifts in its emphasis and focuses more specifically on the root causes, policy will eventually have to adjust as well.

The release of the IPCC 5th Assessment Report Synthesis document on Sunday was a useful reminder of the wealth of measurements, observations and science behind the reality of the anthropocene era and the impact it is having on global ecosystems. While some may embrace this material as proof of society’s “wicked ways” and others may contest it on the grounds of conspiracy or hoax, the real job at hand is to find a way of dealing with the challenge that is posed. Within the 100+ pages of text of the longer report, two parts in particular highlight the scope of what needs to be done.

Within 1.2.2:

Despite a growing number of climate change mitigation policies, annual GHG emissions grew on average by 1.0 GtCO2eq (2.2%) per year, from 2000 to 2010, compared to 0.4 GtCO2eq (1.3%) per year, from 1970 to 2000. Total anthropogenic GHG emissions from 2000 to 2010 were the highest in human history and reached 49 (±4.5) GtCO2eq yr-1 in 2010.

Within 3.2 and 3.4:

Global mean surface warming is largely determined by cumulative emissions, which are, in turn, linked to emissions over different timescales. Limiting risks across reasons for concern would imply a limit for cumulative emissions of CO2. Such a limit would require that global net emissions of CO2 eventually decrease to zero.

There are multiple mitigation pathways that are likely to limit warming to below 2 °C relative to pre- industrial levels. Limiting warming to 2.5 °C or 3 °C involves similar challenges, but less quickly. These pathways would require substantial emissions reductions over the next few decades, and near zero emissions of CO2 and other long-lived GHGs over by the end of the century.

The IPCC have now fully embraced the cumulative emissions concept and taken it to its logical conclusion; near zero emissions within this century. This wasn’t explicitly mentioned in the 2007 4th Assessment Report, but was only really there by inference in the mitigation scenario charts that extend beyond 2050. Anyway, the reference is very clear this time around.

This represents a formidable task given the other half of the problem statement also shown above; that emissions are rising faster than ever. There is a second uncomfortable truth buried within this paragraph, which is the implication that current mitigation policies aren’t working.

So there we have it in a nutshell;

Emissions are rising faster than ever, current policies to stop this aren’t working, but we need to be at zero in 85 years.

Eighty five years is the lifetime of an individual. It means that someone born today will need to see a radical change in energy production within the course of their life, to the extent that it is constantly changing for all 85 years, not just locally but everywhere in the world. Arguably someone born in England around 1820 saw this as the industrial revolution unfolded and the Victorian era took hold. But someone born in 1930 hasn’t actually seen a fundamental change in the energy system, rather an enormous scaling up of what was starting to become commonplace at the time of their birth.

This is the issue that I explore in my new book and which is tackled in the Shell New Lens Scenarios released last year. Both the scenarios show that this puzzle is solvable, albeit in very different ways and with different policy approaches but with different levels of success. A critical factor in both scenarios is the timing and deployment rates of carbon capture and storage (CCS). The earlier this starts and the faster it scales up, the higher the chance of limiting warming to around  2°C. This is also highlighted in the IPCC Synthesis Report which says in Section 3.4;

Many models could not limit likely warming to below 2 °C over the 21st century relative to pre-industrial levels, if additional mitigation is considerably delayed, or if availability of key technologies, such as bioenergy, CCS, and their combination (BECCS) are limited (high confidence).

CCS is of course dependent on a price for carbon dioxide or in its absence a standard of some description to implement capture and storage. These policies are largely absent today, despite over two decades of effort since the creation of the UNFCCC. There are certainly some major carbon pricing systems in place, but most are delivering only a very weak carbon price signal and none are leading to large scale rollout of CCS or show any signs of doing so in the near future. Rather, the emphasis has been on promoting the use of renewable energy and increasing the efficiency of energy use. Both of these policies will bring about change in the energy system and efficiency measures will almost certainly add value to most, if not all economies, but it is entirely possible that large scale adoption of these measures doesn’t actually cause global CO2 emissions to fall.

The IPCC have also put a cost on this policy failure in Table 3.2, which shows mitigation costs nearly one and a half times greater in a world which does not deploy CCS. This high cost comes about because the only way to resolve the scenario models is to limit economic activity as means of mitigation; CCS rollout prevents that from happening.

Another way of looking at this is to imagine the actual climate change consequences of delaying CCS rollout, since the likelihood of limiting economic activity is very low. A back calculation from the Shell scenarios implies that every year large scale rollout of CCS is delayed, 1 ppm of atmospheric CO2 is added to eventual stabilisation. This comes about from the cumulative nature of the problem. As such, a 30 year delay means accepting an eventual concentration of CO2 that is some 30 ppm higher than it need be which in turn has consequences for impacts such as sea level rise.

The negotiators now preparing to head to Lima for COP20 and then to Paris a year later may well be poring over the pages of data and dozens of graphs in the 5th Assessment Report, but the message is nevertheless a simple one, although requiring some bold steps.

My new book, Putting the Genie Back, goes to some length picking apart the climate issue and then explaining why carbon capture and storage (CCS) is such a critical part of the solution set. It eventually becomes clear when you really think it about and consider three things;

  • The huge scale of the fossil fuel based energy system;
  • The way carbon dioxide accumulates in the atmosphere and;
  • The extraction economics of fossil fuels.

But few of us have the time to really think about an issue such as climate change, let alone read books on the subject or attend seminars, lectures and climate conferences (although quite a few of these don’t mention CCS at all and some barely acknowledge the need for a carbon price). Rather, in this word of social media, 140 character tweets and 24/7 News Channels, we often get just a few minutes to come to terms with a concept and form an opinion. As such, is it possible to explain the role of CCS in such a short amount of time?

With an eye on the UN Climate Summit and then the opportunities in the lead-up to COP21 in Paris, the World Business Council for Sustainable Development (WBCSD) has given it a try. The media they have used is video, working with an exciting graphics company called Carbon Visuals. The challenge was to help the audience understand why CCS is important in just a few minutes, not just by being told so, but by being convinced.

Carbon Visuals focussed on two key aspects of the climate issue, that being the huge scale of fossil fuel use and the way in which CO2 from this use accumulates in the ocean / atmosphere system, with further accumulation likely due to the global fossil resource base still to be extracted to meet energy needs.

The visuals depicting scale are very attention grabbing, to help the viewer recognise that fossil fuel use is highly unlikely to diminish in the near term or even vanish in the longer term. For example, daily global coal use alone buries Midtown East Manhattan.

Coal mountain

This is then contrasted with renewable energy, which while growing very rapidly, isn’t even outpacing the growth in fossil fuel use, let alone forcing it down.

The animation steps up a notch when it comes to depicting CO2, which bursts out of Central Park and literally buries New York as it accumulates. These spheres are something of a Carbon Visuals “trademark”, first appearing in an excellent video they made about New York City emissions.

CO2 pile in NYC

Finally, the animation puts this into perspective in terms of global accumulation and the likelihood of exceeding the trillion tonnes of carbon threshold (and therefore 2°C), unless of course large scale deployment of CCS takes place to mitigate such an outcome. Of course a great deal has to happen for this scale of CCS to be built, starting with more widespread application of carbon pricing.

CCS Animation

You can watch the animation here and look in more detail at the images and thinking behind it here.

Betting everything on one colour

In my last post I provided a short review of the IPCC 5th AR, WGIII on Mitigation, with the emphasis on one table which showed how much more expensive mitigation will be over this century without carbon capture and storage. Unfortunately, this pearl from the IPCC didn’t get much coverage. Looking another layer down into the WGIII Technical Report, Chapter 6, the CCS case is very clear;

As noted above, the lack of availability of CCS is most frequently associated with the most significant cost increase (Edenhofer et al., 2010; Tavoni et al., 2012; Krey et al., 2014; Kriegler et al., 2014a; Riahi et al., 2014), particularly for concentration goals approaching 450 ppm CO2eq, which are characterized by often substantial overshoot. One fundamental reason for this is that the combination of biomass with CCS can serve as a CDR technology in the form of BECCS (Azar et al., 2006; van Vliet et al., 2009; Krey and Riahi, 2009; Edmonds et al., 2013; Kriegler et al., 2013a; van Vuuren et al., 2013) (see Sections 6.3.2    and 6.9  ). In addition to the ability to produce negative emissions when coupled with bioenergy, CCS is a versatile technology that can be combined with electricity, synthetic fuel, and hydrogen production from several feedstocks and in energy‐intensive industries such as cement and steel. The CCS can also act as bridge technology that is compatible with existing fossil‐fuel dominated supply structures (see Sections 7.5.5, 7.9, and 6.9   for a discussion of challenges and risks of CCS and CDR). Bioenergy shares some of these characteristics with CCS. It is also an essential ingredient for BECCS, and it can be applied in various sectors of the energy system, including for the provision of liquid low‐carbon fuels for transportation (see Chapter 11, Bioenergy Annex for a discussion of related challenges and risks). In contrast, those options that are largely confined to the electricity sector (e.g., wind, solar, and nuclear energy) and heat generation tend to show a lower value, both because they cannot be used to generate negative emissions and because there are a number of low‐carbon electricity supply options available that can generally substitute each other (Krey et al., 2014).

Importantly, this isn’t just about the cost of mitigation, but about the feasibility of meeting the global 2°C goal. As such, you would expect that CCS should figure at the top of the agenda at a climate conference, but this is rarely the case – in fact, in my experience it is only the case when the conference is actually about CCS.

On May 4-5th, the global climate fraternity will meet in Abu Dhabi for the Abu Dhabi Ascent, the first and only preparatory conference for the UN Secretary General’s Climate Summit on September 23rd in New York. The objectives of the meeting are as follows;

The objective of the Abu Dhabi Ascent is to provide an opportunity for all Governments to be fully informed about the Climate Summit, including how they can bring bold announcements and actions to the Summit, as requested by the Secretary-General. The Ascent will be the only meeting before the Summit in which Governments, the private sector and civil society will come together to explore international and multi-stakeholder efforts that have high potential for catalysing ambitious action on the ground. The Secretary-General set two objectives for the Summit: to catalyse ambitious action on the ground to reduce emissions and strengthen climate resilience, and to mobilize political momentum for an ambitious, global, legal agreement in 2015.

That certainly sounds like a conference where CCS would get some air time, but no, the agenda only includes the following;

  • Energy Efficiency
  • Renewable Energy
  • Short-Lived Climate Pollutants (SLCPs)
  • Transportation
  • Cities
  • Agriculture
  • Forests
  • Climate Finance
  • Adaptation, Resilience and Disaster Risk Reduction (DRR)
  • Economic Drivers

Top of the list is my “old favourite”, energy efficiency, a great way to spur economies and stimulate economic growth, but almost certainly a red herring in the drive to contain cumulative emissions over the course of this century. My real favourite, carbon pricing, is there but well hidden under the obscure heading of “Economic Drivers”. As noted, CCS isn’t there at all.

We might imagine a world of clean, efficient renewable energy and we will need that, but it isn’t obtainable today and possibly not even by the end of this century. It will take time to evolve as the current energy system has evolved over the last 200 years. But the CO2 issue presents us with a pressing problem today that somehow needs a solution. The concern is that in the casino we live in, we seem to be betting all our chips on one colour, green, which might be a gamble too far. The even money bet on CCS and alternatives (renewables, nuclear) is what is needed.

The learning from IPCC WGIII and their scenario analysis seems to be lost on those who are leading the challenging process to bring nations together to solve the climate issue. There is something almost comical about this situation – perhaps an echo from Dr. Strangelove would be “You can’t talk about CCS here, this is a climate conference!”.

The last of the three IPCC 5th Assessment Reports has now been published, but with a final Synthesis Report to come towards the end of the year. The “Mitigation of Climate Change” details the various emission pathways that are open to us, the technologies required to move along them and most importantly, some feeling for the relative costs of doing so.

As had been the case with the Science and Impacts reports, a flurry of media reporting followed the release, but with little sustained discussion. Hyperbole and histrionics also filled the airwaves. For example, the Guardian newspaper reported:

The cheapest and least risky route to dealing with global warming is to abandon all dirty fossil fuels in coming decades, the report found. Gas – including that from the global fracking boom – could be important during the transition, but only if it replaced coal burning.

This is representative of the general tone of the reporting, with numerous outlets taking a similar line. The BBC stated under the heading “World must end ‘dirty’ fuel use – UN”:

A long-awaited UN report on how to curb climate change says the world must rapidly move away from carbon-intensive fuels. There must be a “massive shift” to renewable energy, says the study released in Berlin.

While it is a given that emissions must fall and for resolution of the climate issue at some level, anthropogenic emissions should be returned to the near net zero state that has prevailed for all of human history barring the last 300 or so years, nowhere in the Summary Report do words such as “abandon” and “dirty” actually appear. Rather, a carefully constructed economic and risk based argument is presented and it isn’t even until page 18 of 33 that the tradeoff between various technologies is actually explored. Up until that point there is quite a deep discussion on pathways, emission levels, scenarios and temperature ranges.

Then comes the economic crux of the report on page 18 in Table SPM.2. For scenarios ranging from 450ppm CO2eq up to 650 ppm CO2eq, consumption losses and mitigation costs are given through to 2100, with variations in the availability of technologies and the timing (i.e. delay) of mitigation actions. The centre section of this table is given below;

 IPCC WGIII Table SPM2

Particularly for the lower concentration scenario (430-480 ppm) the table highlights the importance of carbon capture and storage. For the “No CCS” mitigation pathway, i.e. a pathway in which CCS isn’t available as a mitigation option, the costs are significantly higher than the base case which has a full range of technologies available. This is still true for higher end concentrations, but not to the same extent. This underpins the argument that the energy system will take decades to see significant change and that therefore, in the interim at least, CCS becomes a key technology for delivering something that approaches the 2°C goal. For the higher concentration outcomes, immediate mitigation action is not so pressing and therefore the energy system has more time to evolve to much lower emissions without CCS – but of course with the consequence of elevated global temperatures. A similar story is seen in the Shell New Lens Scenarios.

Subtleties such as this were lost in the short media frenzy following the publication of the report and only appear later as people actually sit down and read the document. By then it is difficult for these stories to surface and the initial sound bites make their way into the long list of urban myths we must then deal with on the issue of climate change.

With much anticipation but little more than 24 hours of media coverage, the Intergovernmental Panel on Climate Change (IPCC) released the next part of the 5th Assessment Report, with Working Group II reporting on Impacts, Adaptation and Vulnerability. The report started with the very definitive statement;

Human interference with the climate system is occurring . . . 

But this was immediately followed by a statement that set the scene for the entire assessment;

. . . . and climate change poses risks for human and natural systems.

The key word here is “risk”. This report attempted to explain the risks associated with rising levels of CO2 in the atmosphere and demonstrate how the impact risk profile shifts depending on the eventual change in surface temperature and the response to this through adaptation measures. Unfortunately, the subtlety of this was largely lost in the media reporting.

For example, although the Guardian did use the “risk” word, it chose to open one of its many stories on the new report with the statement;

Australia is set to suffer a loss of native species, significant damage to coastal infrastructure and a profoundly altered Great Barrier Reef due to climate change . . . .

This was under the headline “Climate change will damage Australia’s coastal infrastructure“.

The IPCC report didn’t actually say this, rather it presented a risk assessment for coral reef change around the coast of Australia under different emission and temperature scenarios. This was summarised, along with a wide variety of other impact risks, in a useful chart form with the Australian coral extract shown below.

Coral reef risk

Of course it is the job of the media to translate a rather arcane and technical report into something that a much larger number of people can understand, but it is nevertheless important to retain the key elements of the original work. In this case, it is the risk aspect. With very few exceptions, there is no “will” in this subject, only “could”. Some of those “could” events have a very high level of probability (the IPCC use the term “virtually certain” for 99% probability), but this still doesn’t mean it is certain.

There has been an increasing tendency to talk about climate change in absolutes, such as “stronger hurricanes”, “more violent storms” and “a profoundly altered Great Barrier Reef”, when in fact this isn’t how the science describes the issue. Rather, it is how the media and others have chosen to describe it. This isn’t to say that these risks should be dismissed or ignored, they are real and very troubling, but the outcomes are not a given. Hopefully as others have time to digest the latest IPCC work, this aspect of the story becomes more prominent.

Taking this a step further though, it would appear that even the IPCC have chosen to present the risks with a slight skew. Although they are completely transparent about all the material they have used to build their case, the final presentation in the risk charts doesn’t tell the full story. They have chosen to present only two scenarios in the summary document, the 2 ºC case and the 4 ºC case. There is much to say between these and arguably, the space between 2 and 4 is where the real risk management story lies.

This was analysed in 2009 by the MIT Joint Program, in their report Analysis of Climate Policy Targets under Uncertainty. The authors demonstrated that even a modest attempt to mitigate emissions could profoundly affect the risk profile for equilibrium surface temperature. In the chart below five mitigation scenarios are shown, from a “do nothing” approach to a very stringent climate regime (Level 1, akin to the IPCC 2 ºC case). They note in the report that:

An important feature of the results is that the reduction in the tails of the temperature change distributions is greater than in the median. For example, the Level 4 stabilization scenario reduces the median temperature change by the last decade of this century by 1.7 ºC (from 5.1 to 3.4 ºC), but reduces the upper 95% bound by 3.2oC (from 8.2 to 5.0 ºC). In addition to being a larger magnitude reduction, there are reasons to believe that the relationship between temperature increase and damages is non-linear, creating increasing marginal damages with increasing temperature (e.g., Schneider et al., 2007). While many estimates of the benefits of greenhouse gas control focus on reductions in temperature for a reference case that is similar to our median, these results illustrate that even relatively loose constraints on emissions reduce greatly the chance of an extreme temperature increase, which is associated with the greatest damage.

 Temperature uncertainty

There is a certain orthodoxy in only looking at 2 and 4 ºC scenarios. It plays into the unhelpful discussion that seems to prevail in climate politics that “it must be 2 ºC or it’s a catastrophe.” I posted a story on this late last year. As it becomes increasingly clear that the extreme mitigation scenario required for 2 ºC simply isn’t going to happen, society will need to explore the area between these two outcomes with a view to establishing what can actually be achieved in terms of mitigation and to what extent that effort will shift the impact risk. Maybe this is something for the 6th Assessment Report.

As politicians from all parties don Wellington boots and wade through flooded fields and streets in southern England, the subject of climate change is rising up the agenda. While all but a very few have stayed away from direct attribution of the England floods to climate change, it is also clear that nobody has a good set of words that describe the current situation and the link, or otherwise, to the climate issue. Rather, politicians seem to be stumbling through the discussion, grappling for the correct language to talk about linkage but not to drift into attribution.

The starting point is somewhat loaded, in that the issue itself is now referred to more widely as climate change, rather than global warming. Although both have been part of the lexicon since the 1970’s, the climate reference has certainly won the day (Google Ngram Viewer, see below). It brings with it an expectation that change is underway, whether it is or isn’t for a particular location. Global warming more accurately describes the core issue, i.e. that the atmosphere / ocean system is warming in response to increasing levels of carbon dioxide, but it’s arguably less emotive and exciting. It also doesn’t fully describe the full scope of the CO2 issue. Ngram - Climate vs Warming

Exactly how and by how much the climate will change as a result of ocean and atmosphere warming remains to be seen, although a wealth of science, analysis, and computer modeling certainly doesn’t point to a static situation. Some locations may see very distinct and obvious changes over time, others may see very little. The problem is that we are all very impatient, whereas warming and its consequences will be a long, slow drawn out affair with mixed impacts on specific locations. As a result, the temptation to jump to conclusions is almost overwhelming.

The MIT Joint Program on the Science and Policy of Global Change has been actively exploring how best to talk about uncertainty. Perhaps their most successful tool is the Greenhouse Gas Gamble “wheel of fortune”, which tries to put the uncertainty around warming into terms that people can understand. The Joint Program website offers a nice tool where the reader can “spin” the wheel and see the distribution of results through to 2100, both under a business as usual scenario and with a robust set of policy measure applied throughout the world.

 Greenhouse Gas Gamble

 

As the wheel is spun more and more times, a distribution emerges, which then gives some sense of the changes that may be in store for us. Most importantly, one feature of the “With Policy” case that is highlighted is the complete disappearance of the tail of the distribution, which in the “No Policy” case shows that very high temperature rises are possible. By contrast, even in the world where we take no action on climate at all, there is still some chance, albeit vanishingly small, that the temperature rise will be modest.

 Greenhouse Gas Gamble with spins

 

Tools similar to this could be developed for regional issues, such as precipitation in the UK, drought in Texas and heatwaves in Australia. They won’t be perfect, but may help in better understanding and more importantly, explaining what is going on. For example, even a historical distribution of precipitation for the winter period in southern England with the current winter shown would do a far better job in contextualizing the deluge we are aving, than vaguely saying it was a record and arguing that it might be climate change. A single point sitting several standard deviations away from an otherwise normal distribution would put it in the same category as the 2003 European heatwave, whereas a marginal outlier in a tight distribution might be viewed with less concern.

It may well be the case that the flooding in England is a result of enhanced warming from higher levels of CO2 in the atmosphere. Equally, it may just be part of the chaotic system we call “the weather”. Either way, a more informed discussion needs to take place, supported by data and helpful tools to unravel the messages contained within it.