Archive for the ‘Climate Science’ Category

Assessing the INDCs

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It is now just 100 days until COP21 in Paris.

The summer months have seen many Intended Nationally Determined Contributions (INDCs) submitted to the UNFCCC prior to the assessment deadline of October 1st. This is the date when the UNFCCC secretariat will start work on a synthesis report on the aggregate effect of the INDCs as communicated by Parties. Many organisations are already offering assessments of progress, with most basing this on reductions through to 2030 against a notional 2°C pathway.

However, the climate system doesn’t care about 2030 nor does it respond to changes in annual emissions. The real metric is cumulative emissions over time, with each trillion tonnes of carbon released into the atmosphere equivalent to about 2°C rise in temperature rise (this isn’t precisely linear, but it is a reasonable rule of thumb to use). This means that any assessment must look well beyond 2030 and make some bold assumptions as to where the emissions pathways then go. It also means that the wide variety of pledges using metrics such as the share of renewable energy in the power generation mix, installed solar capacity or emissions per GDP, whilst important in the context of energy system development, offer limited insight into the trend for cumulative emissions.

A good example of this comes from looking at the INDC from China. They have pledged the following;

  • To achieve the peaking of carbon dioxide emissions around 2030 and making best efforts to peak early;
  • To lower carbon dioxide emissions per unit of GDP by 60% to 65% from the 2005 level;
  • To increase the share of non-fossil fuels in primary energy consumption to around 20%; and
  • To increase the forest stock volume by around 4.5 billion cubic meters on the 2005 level.

From an energy emissions context, only the first part of this pledge is really important, but little information is given allowing an assessment of its real impact on the climate system. Some big assumnptions will have to be made.

According to the Oxford Martin School carbon emissions counter, global cumulative emissions now stand at nearly 600 billion tonnes of carbon (2.2 trillion tonnes CO2). Back in November 2014 when China and the USA announced their climate deal, I speculated that the Chinese side of the Sino-US deal could see their emissions rising to as much as 14.5 billion tonnes CO2 per annum by 2030 based on the following assumption;

The USA and China appear to have adopted a “Contraction and Convergence” approach, with a goal of around 10 tonnes CO2 per capita for 2030, at least for energy related emissions. For China this means emissions of some 14.5 billion tpa in 2030, compared with the latest IEA number for 2012 of 8.3 billion tonnes, so a 75% increase over 2012 or 166% increase over 2005. It also has China peaking at a level of per capita CO2 emissions similar to Europe when it was more industrial, rather than ramping up to the current level of say, the USA or Australia (both ~16 tonnes). By comparison, Korea currently has energy CO2/capita emissions of ~12 tonnes, so China peaking at 10 is some 17% below that.

Of course China could still peak at lower levels than this and the economic downturn they currently seem to be facing may ensure this. Nevertheless, two reduction pathways following 2030 give a very different cumulative outlook for the period 2015-2100. It is this cumulative outcome that matters, not where China might happen to find itself in 2030. While the period up to 2030 is important, it only tells a fraction of the story. Chinese emissions over that period will likely add some 50 billion tonnes of carbon to the global cumulative total, but this is small compared to their potential remaining cumulative contribution (i.e, before they are at net-zero emissions). The two pathways below illustrate the difference;

  1. A plateau for about a decade, followed by a long slow reduction through to near zero by 2100 means cumulative emissions from 2015 are around 800 billion tonnes of CO2, or 220 billion tonnes of carbon. In this scenario, Chinese emissions alone take the global carbon emissions total to 820 billion tonnes.
  2. A sharp decline from 2030 to zero before 2080 gives cumulative emissions of 550 billion tonnes, or 150 billion tonnes carbon. In this case the global total rises to 750 billion tonnes carbon based on Chinese emissions alone.

Either way, China will have a profound impact on global cumulative emissions. But this fairly simple analysis illustrates that the period from 2030 onwards is where the real story lies, which to date isn’t covered by any of the INDC submissions. For a 2°C outcome, even the lower of the two scenarios above leaves little carbon space for the remaining 7+ billion people living on the planet throughout the 21st century.

Impact of Chinese Cumulative Emissions

Who knew what and when?

A recent article in the Guardian, which was also carried through a number of other media outlets, implied some prior knowledge within the oil and gas industry of climate change and the impact of carbon dioxide emissions from fossil fuel use long before others had recognised its impact. The assertion was based on unearthed correspondence within Exxon where carbon dioxide emissions were discussed as early as 1981. The article goes on to say that “Climate change was largely confined to the realm of science until 1988, when the climate scientist James Hansen told Congress that global warming was caused by the buildup of greenhouse gases in the atmosphere, due to the burning of fossil fuels.”

In fact, information about the role of carbon dioxide as a greenhouse gas in the atmosphere has been widely available for over a century and has its foundation as far back as the early 19th Century, nearly 200 years ago. At that time, physicists were coming to terms with radiation physics and were attempting to understand why the Earth had a stable temperature. Knowing the energy falling on the planet from the Sun and after building an understanding of the radiation outwards from the Earth itself, the expected temperature of the planet could be derived. Unfortunately the calculation resulted in a number of somewhere around -15°C, which was clearly some 30°C lower than the observed temperature (about +15°C). Something else was in play, but at the time this was unclear. By 1862, an understanding of the role of certain gases in the atmosphere had been established, now more widely known as the “greenhouse effect”.

In 1896, Swedish chemist Svante Arrhenius used this information for a paper on the role of carbon dioxide that remains the foundation of 120 years of analysis of the Earth’s temperature and resulting climate (On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground).


In this paper Arrhenius established a methodology for linking the change in surface temperature with the change in the level of carbon dioxide (carbonic acid as he referred to it as) in the atmosphere. Table VII of the paper showed the results of his calculation for different levels of carbon dioxide in the atmosphere ranging from K=0.67 (where K=1 for the level at the time) to K=3.0. For the latitude of the equator he derived the following results;

Carbonic acid = 0.67 Carbonic acid = 1.5 Carbonic acid = 2.0 Carbonic acid = 2.5 Carbonic acid = 3.0
Temperature change at Latitude 0° -3.02°C 3.15°C 4.95°C 6.42°C 7.3°C

The Arrhenius paper discusses the work of a Professor Högblom, another Swedish scientist of the day, who had even calculated how much the burning of coal at that time (500 million tonnes per annum) might change the surface temperature of the planet. The number was very small, but today annual fossil carbon extraction is some twenty to thirty times greater than this and more importantly the cumulative extraction (which we now know is what actually matters) since the late 19th century is hundreds of time this level.

By the late 1950s, thanks to the work of Charles Keeling of Scipps Institution of Oceanography in California, accurate measurements of atmospheric carbon dioxide were being made. In 1961, Keeling produced data showing that carbon dioxide levels were rising steadily in what became known as the “Keeling Curve”. In 1965, the first truly public warning as to the impact of rising levels of carbon dioxide in the atmosphere came from the President’s Science Advisory Committee (President Lyndon B. Johnson), with the words “Through his worldwide industrial civilization, Man is unwittingly conducting a vast geophysical experiment. . . . . This may be sufficient to produce measurable and perhaps marked changes in climate, and will almost certainly cause significant changes in the temperature and other properties of the stratosphere.

There have been many other such references and warnings, ranging from the 1988 testimony to Congress by NASA scientist James Hansen to Al Gore’s film Inconvenient Truth in 2006. Through all of these the story hasn’t really changed from the original calculations of Arrhenius in 1894, rather the understanding and methodology has been increasingly refined and improved.

The above timeline isn’t new and can be found in much more detail in many books, blogs and periodicals. Nor is it even close to comprehensive, with dozens of other scientists and institutions making important contributions to the early analysis, particularly in the 1950s. Nevertheless, it seems to need repeating. Although atmospheric warming may not have been a dinner table conversation in the 1980s, it wasn’t a secret either. A look at the use of the phrases “greenhouse effect”, “global warming” and “climate change” shows that they appeared in books in the 1970s.


Nor was it largely confined to the realm of science. Hollywood had even picked up on the issue in the 1973 film Soylent Green, where the greenhouse effect is specifically mentioned and is to some extent a core issue in the dystopian future that is postulated.

Soylent Green

Rather, what is unusual about the climate issue is the present day questioning of the background science that has come some 100-200 years after the scientific basis was first formulated and largely established, rather than at the time. In my forthcoming book, “Carbon Pricing Matters”, I touch on this issue as follows;

The need to manage global emissions and put a halt to the relentless build-up of carbon dioxide in the atmosphere requires the intervention of governments and cooperation between them to ensure their success; particularly when implemented through a cost on carbon dioxide emissions. There is an ongoing debate around the role of government and the degree to which it should be allowed to address the issue of global warming. There are many who believe that government should have only a modest role in society; others accept a much wider role, including one to solve broad-based issues that affect society at large, for example, the build-up of carbon dioxide in the atmosphere. For the latter group, a carbon price may not go far enough; it is a tool designed to tease out the solution over a generation or more. In the case of those who seek to limit the role of government, the imposition of a pricing mechanism across the entire economy can be seen as a step too far and may even raise questions about the foundation upon which the mechanism is based; the science of climate change.

I have just returned from a personal vacation expedition to the European high Arctic, starting in Longyearbyen, Svalbard and ending in Iceland via the East Coast of Greenland. The trip was on the National Geographic Explorer, a 148-passenger expedition class vessel with ice strengthening.

It was an extraordinary trip and many aspects of it offered opportunities to reflect on the big issues of energy transition and climate change. This started in Longyearbyen itself, where it turns out that in the country of hydro electricity (Norway) this small town runs on coal, mined locally. Svalbard even exports coal, although some of the original mines have long been abandoned. Perhaps in this land of vast glaciers and freezing temperatures hydro isn’t practical, but there wasn’t a wind turbine to be seen either. Wind seems like an obvious contender here but even in the Arctic days of dead calm are possible; we experienced this for nearly two full days in the middle of the Greenland Sea. Of course solar is a non-starter with months of darkness. Powering such a location with dependable 24/7 electricity seems to come down to coal. Equally surprising was that some remote northern towns we visited in Iceland were powered by diesel generator, not geothermal.


Svalbard Coal Mine

It doesn’t require much travel in Svalbard to come across magnificent glaciers, but even here there were signs of change. Most of the glaciers we saw appeared stable, but one in particular was retreating rapidly and the early summer was already revealing large melt water streams on its surface. The retreat was clearly visible, with the slow moving foliage line marking the original and fairly recent (in glacial terms) position of the glacier.

Retreating Glacier

Glacier Meltwater

Similarly in Iceland, all but one of that nation’s glaciers are reportedly in retreat. Observable rapid change in one Svalbard glacier isn’t sufficient evidence to reach a conclusion on the state of the Arctic, but it was interesting to see nevertheless. There was also an indication of change in the permafrost, although once again this was limited to a specific observation in one of the handful of locations we visited. Close to a site where we had come face to face with several curious walruses, the soft thawing ground had collapsed into the sea as a river of mud. This might well be a regular event, but if that were the case it was hard to see how the landscape had survived for such a long period.


Permafrost mud

Climate change was a constant topic of conversation on the ship, in part because there was a talk on the subject, further due to the link with National Geographic but also because of where we were. Being a relatively small ship it didn’t take long for most people to know of my link with the issue, so my vacation was filled with dinner discussions about carbon pricing (given the significant number of Australians on the passenger list), renewable energy and climate science. This wasn’t always easy, with a few of the American travellers arguing from the standpoint of information they heard on certain talk radio shows. But it was always interesting and I enjoyed the sparring on the issue. It was also very apparent that National Geographic travellers are deeply interested in the subject and for the most part, very well informed.

The wildlife was a highlight, but here again there was an interesting sign of change. We had two excellent encounters with wandering polar bears, scouring the ice edge for their next meal, and one sobering encounter with the remains of such a meal. This would normally be the carcass of a seal, but in this instance it was the remnants of a white beaked dolphin, a new phenomenon that has only very recently been observed in the high latitudes. These dolphins aren’t normally found in this area in spring when the pack ice is still widespread and therefore may have become trapped in shifting ice.  They then become prey to the region’s most effective predator, the polar bear. The current view on this is that warmer waters may be encouraging the creatures to move north earlier in the year, therefore exposing them to this new and more dangerous environment.

Polar Bear in Arctic Landscape

Polar Bear Food

But there is one constant in this part of the world and that is ice. Lots of ice. Although there is clear satellite evidence of ice loss from Greenland and declining sea ice in the Arctic Ocean, the ice nevertheless got the best of us. The trip included a passage through the Greenland Sea with one or more stops in Greenland itself, but the latter wasn’t to be. Thick multi-year sea ice kept us some 80 miles from the Greenland coast and no landing was possible. Although the ship is ice strengthened it is not an icebreaker, so we were defeated in a year when the ice cover was tracking below the 2012 minimum, at least until mid-June for the Arctic as a whole.

Midnight Ice

Arctic Sea Ice Extent July 2015

The ice provided a wealth of photographic opportunities, including one of the ship taken far out at sea from a zodiac, but in dead calm conditions.

Ship and Ice

We did get a consolation prize for missing out on Greenland, a visit to Jan Mayan. This is a tiny volcanic island in the middle of the Greenland Sea, but rising rapidly to over 2 kms the volcano itself was anything but small. Needless to say, it was spectacular.

Jan Mayen

You can see a complete set of my pictures of this trip here.

The past few weeks, highlighted by the Business & Climate Summit in Paris and Carbon Expo in Barcelona, has seen many CEOs, senior political figures and institutional leaders call for increased use of carbon pricing. This is certainly the right thing to be saying, but it begs the question, “What next?”. Many countries are already considering or in the process of implementing a carbon pricing system, but still the call rings out. While uptake of carbon pricing at national level certainly needs to accelerate, one critical piece that is missing is some form of global commonality of approach, at least to the extent that prices begin to converge along national lines.

On Monday June 1st six oil and gas companies come together and effectively called for such a step in a letter from their CEOs to Christiana Figueres, Executive Secretary of the UNFCCC and Laurent Fabius, Foreign Minister of France and President of COP 21. Rather than simply echo the call for carbon pricing, the CEOs went a step further and specifically asked;

Therefore, we call on governments, including at the UNFCCC negotiations in Paris and beyond – to:

  • introduce carbon pricing systems where they do not yet exist at the national or regional levels
  • create an international framework that could eventually connect national systems.

To support progress towards these outcomes, our companies would like to open direct dialogue with the UN and willing governments.

The request is very clear – this isn’t just a call for more, but a call to sit down and work on implementation. The CEOs noted that their companies were already members of, amongst other bodies, the International Emissions Trading Association (IETA). IETA has been working on connection of (linking) national systems for well over a year (although the history of this effort dates back to the days of the UNFCCC Long Term Cooperative Action – LCA – workstream under the Bali Roadmap) and I am co-chair, along with Jonathan Grant of PWC, of the team that is leading this effort.

Late last year IETA published a strawman proposal for the Paris COP, suggesting some text to set in place a longer term initiative to develop an international linking arrangement. I spoke about this at length to RTCC at Carbon Expo in Barcelona.

DCH Interview

The strawman is what it implies, an idea. It could be built on to develop a placemarker in the Paris agreement to ensure that the framework mentioned by the six CEOs actually gets implemented in the follow-up from Paris – as the CDM was implemented in the follow-up from Kyoto.

From my perspective, this week wasn’t just about carbon pricing, but also about climate science. On the same day that the FT published its story on the letter from the oil and gas industry CEOs, The Guardian chose to run a front page story implying that I had tried to detrimentally influence (apparently being a former oil trader!!) the content of the London Science Museum’s Atmosphere Gallery, a display on climate science that Shell agreed to sponsor some years ago. The reporter had based his story on exchanges between Shell and the Science Museum staff when the gallery was looking to do a recent refresh.

I did engage in such a discussion and I did make some suggestions as to content which I thought was new and interesting since the Atmosphere Gallery was first established. Unfortunately The Guardian wasn’t able to publish my proposals as they were put forward during a meeting between me and two staff members from The Science Museum, so to complete the story I will publish them here. Although this particular piece of science dates back to a 2009 Nature article by Oxford University’s Professor Myles Allen and his team, it didn’t feature in the Gallery when it was first put together (the Advisory Panel met during 2009 as part of the design phase of the Gallery). But today, it is the foundation work behind the concept of a global carbon budget which has become a mainstream topic of discussion. My angle on this was to illustrate the importance of carbon capture and storage in the context of this science, but with an emphasis on the science itself. My discussion with The Science Museum staff members took place on 23rd June 2014 and I asked them to consider the following for the refresh of the gallery:

1. As background, three papers that have come from Oxford University:

  • Warming caused by cumulative carbon emissions towards the trillionth tonne

Myles R. Allen, David J. Frame, Chris Huntingford, Chris D. Jones, Jason A. Lowe, Malte Meinshausen & Nicolai Meinshausen

  • Greenhouse-gas emission targets for limiting global warming to 2°C

Malte Meinshausen, Nicolai Meinshausen, William Hare, Sarah C. B. Raper, Katja Frieler, Reto Knutti, David J. Frame & Myles R. Allen

  • The case for mandatory sequestration

Myles R. Allen, David J. Frame and Charles F. Mason

2. Consider using (or adapting) a trillion tonne video made by Shell where Myles Allen talks about CCS in the context of the cumulative emissions issue:

3. Consider putting the Oxford University fossil carbon emissions counter in the Atmosphere Gallery as this would help people understand the vast scale of the current energy system and the rate at which we are collectively approaching the 2°C threshold;

Trillionth Tonne

4. Reference the Trillion Tonne Communique from Cambridge:

5. Offer the use of the Shell “CCS Lift” (an audio-visual CCS experience) to help explain this technology to the gallery visitors.

My pitch to The Science Museum was that this approach offered a real opportunity to feature the Science Museum and the Atmosphere Gallery in the very public discussion on carbon budgets, get some good media attention in the run-up to Paris 2015 (e.g. through the very visible counter), tell the CCS story in context (the Myles Allen video and the CCS audio-visual display) and raise awareness of the cumulative nature of the problem (i.e. the science). In the end they decided not to use this material, but I stand by the proposal.

For Earth Day

All the air in the atmospere but at surface conditions:


All the CO2 emitted in one day:


Courtesy Carbon Visuals

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.