Interactive Carbon IQ Test, and real climate change solutions

Interactive Carbon IQ Test, and real climate change solutions

The above 'Carbon IQ test' is an excellent way of exploring how much you know about the carbon cycle, and what that means for viable solutions to our climate challenge. Have a go at it before checking out the information below. The below diagram, by Peter Donovan of the Soil Carbon Coalition, shows the amount of carbon stored in each stage of the terrestrial carbon cycle, in which carbon moves from the atmosphere, to vegetation via photosynthesis in the form of complex carbon compounds (plain 'C' in the animation), to litter and soil when the plants or leaves die, and back to the atmosphere as carbon dioxide via decay, oxidation, or burning. The facts that soil is by far the biggest carbon reservoir over which we have any direct control, and that it has proved possible to double the carbon content of soils in a decade, are why I believe that agriculture and land use may be the key frontier if we are to maintain a hospitable climate. (Figures taken from Sequestration of atmospheric CO2 in global carbon pools, Energy and Environmental Science, 1:86-100 (2008). Also note that there is about 15 times more CO2 in the oceans than in the land biosphere and atmosphere combined) In earlier posts I have looked into the climate science and shown that it is now not only necessary to reduce emissions of CO2, but to actually draw down CO2 from our atmosphere and reduce the amount that is already up there. Soil carbon can truly claim, without a hint of greenwash, to be one of nature's own solutions. The Woods Hole Research Centre has found that around 25% of carbon build-up in the atmosphere over the past 150 years has come from land use change, mainly deforestation and farming. Ohio University and others put the figure at around 50%. Organic farming techniques like avoiding nitrogen fertiliser and building up the soil's carbon content can slow this trend.
Organic and non-organic soil carbon
But where it gets really exciting is when we realise that design systems like permaculture and keyline mean that this trend can be reversed, sucking carbon out of our atmosphere while also improving the quality of our soils to enhance food and water security, flood resilience and local community self-sufficiency. I have always been a little sceptical of 'win-win' solutions, but when they simply emerge from ending our present 'lose-lose' processes, I'm a big fan. At a European Commission conference in June last year Prof. Rattan Lal of Ohio University presented findings that, with changes to agriculture and land use, terrestrial ecosystems could naturally reabsorb sufficient CO2 to reduce atmospheric concentrations by at least 50ppm from current levels (thus taking us back under the campaigners' favourite, 350ppm). There is not yet an abundance of research in this area, but it is a tantalising possibility, and if there is one resource I recommend casting your eyes over, it's this slideshow, produced by the Soil Carbon Coalition. Edit (08/01/10) - I was sent a link to the below video by the LifeWorks Foundation. More similar videos can be seen here.
Carbon Offsetting, what’s it really about?

Carbon Offsetting, what’s it really about?

Off the back of taking part in CheatNeutral's spoof chat show 'Going Neutral' at the Science Museum, this feels like the perfect time to take a look at the concept of carbon offsetting, the most recognised example of which is the planting of trees to 'soak up' our carbon emissions, thus supposedly making our net impact 'carbon neutral'... Now there is no denying that the right trees, growing in the right place, are a truly wondrous thing, with myriad benefits for local people and wildlife, and for the global climate. Indeed, I am a long-term supporter of organisations like Tree Aid and Trees for Cities, which have long been carefully planting trees where they are most appropriate. Yet neither these charities nor I claim that my donations give me any kind of right to emit more carbon (or to make fewer efforts to emit less). I donate for the traditional reason - simply because I believe it contributes to creating the kind of world we all want to live in. I might donate to Amnesty for the same reason, but would any of us claim that in doing so I earn the right to perform a small amount of torture? This comparison lays bare the true nature of 'carbon offsetting'. The claim is that we are doing some good to compensate for the unfortunate damage caused by our lifestyles, but the truth is that the damage caused by our emissions is (more than) offsetting the good we might hope to do with our donations to these offsetting companies. And why would we choose to send our money to them ($705m last year, worldwide), rather than to the charities mentioned above? Because we have a reason to believe that they will do more good with our money? Or because we believe that they have some kind of moral sanction to cleanse our consciences, with their websites full of soothing words? Carbon offsetting Not to mention the fundamental physical problem with planting trees to offset emissions. Carbon in nature moves through what is known as the active carbon cycle, cycling between the atmosphere, oceans and biosphere as air and water meet, and as life on Earth breathes, lives and dies. There is also inactive carbon (technically part of a much, much slower cycle), laid down in long-term deposits to which we grant names such as "fossil fuels" or "the white cliffs of Dover". These are, if you like, Earth's natural form of carbon sequestration. So when we extract fossil fuels and burn them, we are moving the inactive carbon they contain into the active carbon cycle. If we then lock it back up in forests or any other aspect of the biosphere, we are not removing it from the active carbon cycle - we are not offsetting the deed done. Carbon sealed in coal or oil would have remained there for many millennia, but trees are not nearly so long-lived, especially in a rapidly-changing climate, and when they die and decay the carbon is released into the atmosphere once more. The difference in timescale is striking - the lifetime of a tree is orders of magnitude shorter than the 'lifetime' of a coal or oil field... trying to stabilise our climate with tree planting is like trying to keep sea levels down by drinking more water. So by all means plant some trees - or, failing that, financially support others in doing so - but give not a moment's credence to the notion that these actions give you some moral right to ignore your own contribution to the world's most pressing challenge. Of course, despite the public perception, proponents of carbon offsetting argue that they have moved on from tree planting, and now concentrate on schemes to build renewable energy infrastructure, fund energy efficiency projects, reduce industrial greenhouse gas emissions etc, thus preventing emissions and avoiding the inconvenient truth about carbon cycles. But the more insidious problem with all carbon offsetting is that it is the inevitable 'perfect consumerist solution' to climate change - "just pay us some money and you can forget about it all and get on with your life". Inconveniently enough, peak energy and climate change together represent probably the greatest challenge in the history of humanity, and paying $12 here and there just is not going to cut it. Hypocrisy - carbon offsetting If we are serious about retaining a hospitable climate, we need a fundamental re-evaluation of our entire way of life, and the only way that will come about is through changes in the fundamental stories we tell ourselves about life and what it means. The notion of carbon offsetting is an offshoot of our deep cultural story that money equals value, and that the key way to contribute to something is to give money to it. Until this mindset changes, we will not find our way out of the mess into which we are hurtling head first. Douglas Adams put it well, "This planet has, or had, a problem, which was this. Most of the people living on it were unhappy for pretty much all of the time. Many solutions were suggested for this problem, but most of these were largely concerned with the movements of small, green pieces of paper, which is odd because on the whole it wasn't the small, green pieces of paper which were unhappy..." And yet, for many it is becoming hard to even conceive of any way of measuring the value of life other than small, green pieces of paper, or computerised digits in a bank account. One good friend (and Philosophy graduate) memorably described money as the only way he knew to 'keep score' on his life. And in a world overwhelmingly dominated by money, it is all too easy to feel alone and lose resolve when trying to live by unpopular alternative beliefs. Yet it is interesting to note that, as in so many cases, our intuitions and instincts do not seem to match with the beliefs we are conditioned to. One example would be the musicians who outright refuse to sell their songs to advertisers, despite that this is by far the most lucrative market for their art. I have heard it argued that "if they are so holy, why don't they take the million dollars and give it to charity? After all, someone else will surely sell the advertisers a catchy song, and probably keep all the money for themselves". Nonetheless, we instinctively feel a respect and admiration for their decision to turn down the easy buck. But why? My theory is this. Even without studying the detail, we recognise that the whole financial system is designed in such a way that money flows inexorably to the top. That the bankers and financiers who to all intents and purposes run the system are essentially able to magic more money out of thin air than we could earn through a lifetime of hard graft. And that if this is so, then any decisions in the world that will be determined by money will be determined by them - despite all the lists of what could be done with the money, in reality a musician's million dollars would barely make a dent. Shell - carbon offsetting All of which means that the only things which we do not cede to their control - the only things, if you will, that remain sacred - are those things on which we simply and absolutely refuse to put a price, whether that be a work of art, an entire natural environment, or the carbon cycle that maintains a benign climate. Oscar Wilde wrote over a century ago that, "Nowadays people know the price of everything and the value of nothing". This still rings true, but if we can avoid actually giving a price to everything, perhaps we will leave open the path back to real value. -- Edit - 27 March 2012 - A noteworthy event today, Prof. Kevin Anderson of the Tyndall Centre for Climate Change Research - a man for whom I have great personal respect - has withdrawn from the Planet Under Pressure 2012 Conference due to being forced by the organisers to participate in carbon offsetting. He has explained his reasons, carefully justifying his belief that "offsetting is worse than doing nothing, it is without scientific legitimacy, is dangerously misleading and leads to a net increase in emissions".
All Party Parliamentary TEQs report – rationing, not carbon trading

All Party Parliamentary TEQs report – rationing, not carbon trading

As the evidence for the utter inapplicability of free market carbon trading to our climate emergency continues to pile up, interest continues to grow in the less PR-friendly alternative - the rationing of carbon-rated energy. Yesterday, the UK Government's All Party Parliamentary Group on Peak Oil and Gas previewed a draft report commissioned from The Lean Economy Connection. The report, which I co-authored with Dr. David Fleming, emphasises the necessity of considering our pressing energy challenges alongside climate change, and argues that national energy rationing systems on the model of TEQs (Tradable Energy Quotas) will be essential to the fair distribution of fuel as shortages unfold, with implementation now an urgent priority for the UK. John Hemming MP, Chairman of the All Party group, stated that the UK government remains unprepared for peak oil: "The evidence is now strong that peak oil is either upon us or just over the horizon. Even the International Energy Agency accepts that an oil supply crunch seems to be on its way. The UK government should urgently consider the TEQs system, as I believe it's the only comprehensive and fair way to tackle climate change and the coming oil crisis." "The alternative to rationing by tradable quotas is to hold back consumption through massive price increases. This gives economic instability, unemployment and fuel poverty. We need to plan for a system to give some stability in what will soon be a sellers market for fossil fuels rather than a buyers market." Alternative route TEQs were also the subject of a Parliamentary Westminster Hall debate on the 18th June, called by the Chairman of the House of Commons Environmental Audit Committee, after the EAC came out firmly in favour of what they term 'Personal Carbon Trading' (PCT) following DEFRA's pre-feasibility study in May 2008. Despite their welcome enthusiasm, I do find this 're-branding' of the debate somewhat pernicious. Of course it is to some extent understandable - politicians deal in public consent, and words like "quotas" and "rationing" bring with them the distinctly unwelcome connotations of shortage and war. Indeed, perhaps only truly horrific words like "taxation" would rank lower in a popularity contest. Yet a moment's thought shows us that this bad name is undeserved - rationing is a response to hard times, not the cause of them, and in times of shortage we cry out for fair shares. We need only imagine wartime Britain without a rationing system. The difficulty today is perhaps that the electorate do not yet recognise the scale or urgency of the energy/climate problem we face, and so are more than happy to do without the inconvenience a solution might bring. WWII travel poster Still, politics is politics, we might think, and in a democracy ideas must be 'sold' to the electorate (here H.L. Mencken comes to mind: "Democracy is the system where everybody gets what the majority deserve"). Yet despite the names "PCT" and "TEQs" often being used interchangeably, the distinction between the two is not merely a matter of marketing, it is the distinction between two discrete schemes, and between two very different cultural approaches. It is the distinction between a system that maximises economic growth and hopes to reduce emissions, and one that guarantees emissions reductions and lets the market (and citizens, businesses, communities...) figure out the best solutions within that context. It is the distinction between a 'market-based framework' (a la the ineffectual EU ETS) and a framework within which the market is constrained. When it comes down to it, there is no getting away from the fact that it is not PCT - an extension of the discredited carbon trading model to the level of the individual - that we need, but TEQs - energy rationing - with the size of our rations determined by energy availability and the latest science on retaining a hospitable climate. It is true that trading is a necessary part of such a scheme (both since prohibiting the exchange of rations in the past has always led to substantial black market activity, and since certain vocations intrinsically require more energy, meaning that a non-tradable equal entitlement would simply destroy many professions) but it is not the essence of the scheme. The heart of the scheme is a non-negotiable respect for the limits set by physical reality, and a desire to harness the collective genius of the populace in thriving within those limits. Sadly, the slightly subtle distinction between the necessity of utilising trading in an energy rationing scheme, and the insanity of 'trading as replacement for solution', leaves plenty of ground for the professional spin doctors to confuse those who don't have time to unpick the differences, leading us ever closer to the non-solution of a scheme designed to pander to the popular pretence that we can simply ignore the realities of our time. Indifference --- The Dutch edition of David Fleming's seminal description of TEQs - Energy and the Common Purpose - has also recently been published.
Despairing of Ed Miliband, Becoming a Filmstar, and Other Adventures

Despairing of Ed Miliband, Becoming a Filmstar, and Other Adventures

It has been another crazy whirlwind of a month, with this weekend set to be the first in five which I get to spend in Transition Town Home, having spoken recently in Bungay, Glastonbury, Belsize Park and the Forest of Dean, as well at the Transition Conference (I hate that name, can't we call it a 'Gathering' or something?) in Battersea, and at the Sunrise Celebration Festival. One highlight for me was watching the world première of the movie "In Transition" and being surprised and delighted to find that I was in it (having completely forgotten the quick interview they grabbed with me at my book launch!). Another was meeting an A-Level teacher who is already using my book as a teaching aid for his Environmental Design students. But perhaps of wider interest was the fact that Ed Miliband, Secretary of State for Energy and Climate Change, turned up at the Transition Conference as a 'keynote listener', but still managed to drop a few bombshells. Ed Miliband at the Transition Conference When we buttonholed him for a bit of a chat (audio here, courtesy of Traydio.com), I was pleased to hear that he understood the need for Government to remain a step removed from the Transition movement in order to avoid "strangling" it. However, I must confess I had to refrain from gasping as he declared that: "If you think about the history of the debate on peak oil as I understand it, climate change makes debate about peak oil a bit of a second-order debate, because we have to start making the transition to low carbon forms of energy in any case. Whether you think that peak oil's in 2020, 2030 or 2040... I don't need to have the debate about peak oil... to know that we have to start making the transition as quickly as possible." Where to begin? Clearly Ed's understanding of the history of the peak oil debate differs a little from mine. Let's start with the obvious - with many experts agreeing that we likely saw peak oil last year, for our Minister for Energy to be pondering how many decades in the future it might lie is, frankly, terrifying. But what I personally find even more worrying is that he (and thus presumably his department) has not yet grasped that climate change and peak oil often pull in opposite directions. Perhaps Ed should cast his eyes across the Atlantic to the US Congress, where the advocates of Climate Change Bills (to implement strict carbon budgets) are doing battle with the champions of Energy Independence Bills (to subsidise carbon-intensive tar sands and coal-to-liquids projects). Ed Miliband at the Transition Conference As I wrote here last year, and more recently in The Transition Timeline, there is a very real tension between addressing climate change and addressing peak oil, and policy based purely on one side of this equation could be very destructive indeed. Unfortunately, our government is still caught on the horns of this 'supply side dilemma', and is desperately casting around for more rapidly-deployable low-carbon energy supplies. It is only slowly dawning on them that renewable supply cannot increase as fast as oil and gas are declining, that nuclear only makes the problem worse, and that coal is not an option if we want a habitable planet. The inescapable conclusion is that if we are to treat climate change with the seriousness which it undoubtedly deserves, then we may well have already entered our years of energy descent. The only reasonable response is to find ways to thrive in this context - to reduce energy demand in line with the reducing supply - but as yet Ed still believes that only Denial sells to the voting public: "In a way I'm less optimistic than you are... you're optimistic that you can persuade people to adopt a sort of "no growth" model of society - I'm pretty convinced that you couldn't persuade people of that... Even if you were right about your model of society, I just don't believe that you're going to convince people of that" Actually, I do agree with Ed that we need to think long and hard about what "economic growth" actually means before we debate whether we want it, though I'm not sure we'll see eye-to-eye when that debate reaches its head. Of course it doesn't come as an overwhelming surprise to see my perspective deemed darker yet more optimistic than the Government view, but since the Transition Vision of the future seems about the only desirable outcome out there to shoot for, I think I'll just keep right on shooting, whether Ed rates our chances or not. Having said that, with Rob's recent post on 'burn out' in mind, it's definitely time for a day off for me. Tomorrow is my birthday, and I will be taking a hard-earned breather at Kew Gardens with my beautiful and inspirational girlfriend. Back soon!
Kew Gardens
The climate science translation guide

The climate science translation guide

We are all familiar with the concept of climate change, and the need for reduced carbon emissions, but really getting a handle on the scale of the problem can be difficult, thanks to all the confusing terminology. I looked all over the web for a straightforward comprehensive explanation of terms like Global Warming Potential (GWP) and the different meanings of CO2equivalent but I couldn't find it, so eventually I decided to spend some of my time (and the time of many helpful friends and colleagues) on creating one. I didn't count on quite how intricate the underlying science is (it became ever clearer to me why there is so much confusion in this area), so the process took some considerable time, but I believe that this post is now something that many will find useful. It has been checked for accuracy by qualified experts. In order to fully understand the relationship between greenhouse gas emissions and global temperature increase then, we first need to consider the concept of radiative forcing. Radiative forcing illustrated - Climate Science Translation Guide The Earth is continually receiving energy from the Sun, and continually losing energy into space (as space is much cooler than the Earth). Radiative forcing is simply the difference (measured in watts per square metre) between the amount of energy received and the amount of energy re-radiated back into space. In other words it is the rate at which the planet’s surface is either warming or cooling. [1] If the planet were losing energy at the same rate it was gaining it then the radiative forcing would be zero and the temperature would remain stable at its current level – this state is called thermal equilibrium. Since a hotter planet loses more energy into space, the natural system tends to move towards thermal equilibrium. However, rising greenhouse gas concentrations (measured in parts per million – ppm [2]) in the atmosphere act like an insulating blanket, reducing the rate at which energy can escape into space, and so affecting radiative forcing, which in turn affects the temperature. The rough illustrative graphs below give an idea of these relationships and show the time delay between changes in emissions rates (up or down) and temperature changes. [3] Climate - Business As Usual - Climate Science Translation Guide The graph below shows that if we can bring anthropogenic (human-caused) emissions back down we can stabilise greenhouse gas concentrations and bring radiative forcing back towards equilibrium, but at a higher temperature. [4] Climate with emissions reductions - Climate Science Translation Guide So, emissions contribute to greenhouse gas concentrations which in turn contribute to radiative forcing, but it is radiative forcing that determines the rate of change in temperature. Armed with this understanding, the terms below become clearer: Global warming potential (GWP) is an estimate of how much a given greenhouse gas contributes to Earth’s radiative forcing. Carbon dioxide (CO2) has a GWP of 1, by definition, so a gas with a GWP of 50 would increase radiative forcing by 50 times as much as the same amount (mass) of CO2. A GWP value is defined over a specific time interval, so the length of this time interval must be stated to make the value meaningful (most researchers and regulators use 100 years). For example, methane has a GWP of 72 over 20 years, but a lower GWP of 25 over 100 years. This is because it is very potent in the short-term but then breaks down to CO2 and water in the atmosphere, meaning that the longer the period you consider it over, the more similar its effect is to that of CO2 alone. [5] Equivalent carbon dioxide (CO2e) is an estimate of the concentration of CO2 (in ppm) that would cause a given level of radiative forcing. [6] For example, the IPCC’s[7] latest report in 2007 considered the effects of the main greenhouse gases currently present in our atmosphere and calculated a CO2e for these of around 455ppm (and rising). This means that (over a defined period) the radiative forcing effect of these gases at current concentrations is roughly equal to the effect a 455ppm concentration of CO2 alone would cause. This particular CO2e calculation takes into account the six major greenhouse gases considered under the Kyoto Protocol, and so may be labelled CO2e(Kyoto). [8] However, the orange line in the graphs above represents the total radiative forcing of the planet. This is the important figure – the one that determines the rate of change in Earth’s temperature – and as well as the Kyoto gases it is also affected by other factors such as the effects of sulphate aerosols, ozone and cloud formations. The chart below quantifies the effect of each of these factors, and we can see that a number of them (those coloured blue) are actually negative forcings, which act to reduce the total radiative forcing. Because of these, the equivalent CO2 for all forcings combined - CO2e(Total) - is, thankfully, lower than CO2e(Kyoto). The IPCC’s latest figures give CO2e(Total) as roughly 375ppm. [9] When we hear scientific debates between stabilisation scenarios of, say, 350ppm, 450ppm or 550ppm it is CO2e(Total) which is under discussion. So this 375ppm is the key number, but it has a far wider margin of error than the others. This is because it is relatively easy to measure the atmospheric concentrations of greenhouse gases, and the GWP of those gases, but considerably more difficult to account for all the effects that contribute to the ultimate CO2e(Total) radiative forcing over a given period. The column in the below chart labelled LOSU stands for the “Level Of Scientific Understanding” of the various forcings, and as we can see it is not universally high. [10] IPCC table of components of radiative forcing - Climate Science Translation Guide Radiative forcing is the fundamental issue, but it is easy to see why most discussions revolve only around emissions – not only are CO2 emissions much the largest way in which humanity is changing the planet’s radiative forcing, but they are also easier to understand conceptually and easier to quantify than radiative forcing. According to the IPCC atmospheric CO2 concentrations were 379ppm in 2005, which coincidentally happens to be close to our best estimate of 375ppm CO2e(Total). Unfortunately this coincidence also creates a good deal of confusion, as it is not always clear which measure an author is referring to – scientists often assume that this is obvious to their audience, and many others do not themselves fully understand the distinctions between CO2, CO2e(Kyoto) and CO2e(Total). [11] The other source of confusion is that all of the numbers we have discussed are based on evolving science, and many can only be given approximately. For example, these are the IPCC’s given figures for the GWP of methane over 100 years, taken from their last three reports: 1995 - 2nd Assessment Report (SAR): Methane 100 year GWP = 21 2001 - 3rd Assessment Report (TAR): Methane 100 year GWP = 23 2007 - 4th Assessment Report (AR4): Methane 100 year GWP = 25 These changes are entirely appropriate – the values should become more accurate over time as new measurement methods or changes in scientific understanding develop – but it makes it important to check where any figures are sourced from. [12] Where we are today So let’s take stock. Below are the latest IPCC figures, which define the situation as it was in 2005: CO2 = 379ppm (error range: minimal) CO2e(Kyoto) = 455ppm (error range: 433-477ppm) CO2e(Total) = 375ppm (error range: 311-435 ppm) [13] Emissions are still increasing year-on-year (faster than projected in any of the IPCC's scenarios) and atmospheric CO2 concentrations are currently rising by between 1.5 and 3 ppm each year. They are at roughly 385ppm in mid-2008 (for the very latest updated CO2 figure click here). It is worth noting that the pre-industrial concentration of CO2 in our atmosphere was 278ppm and did not vary by more than 7ppm between the years 1000 and 1800 C.E. [14] Global average (mean) temperature has already risen by around 0.8°C since pre-industrial times, and a minimum additional 0.6°C of warming is still due from emissions to date - the delay in warming being a consequence of the time-lags in the system discussed above. [15] Ok, that's it! If you followed everything here you should be well-equipped to consider the scientific discussion of climate change. Indeed, you may find you understand it better than some of those who write and speak about it! Hopefully this post will provide a resource to aid wider understanding of the changes we are causing to our global climate system and the climate emergency we are facing. Should any inaccuracies come to light I will of course amend them. This work forms part of my forthcoming book The Transition Timeline, produced in partnership with the Transition Network, and set for publication in March 2009 and available now, published by Green Books. It uses the understanding outlined here to examine the wider context of climate change and peak oil, discuss the options facing our communities and consider the cultural stories which underlie our choices. Climate change with scientific realism - Climate Science Translation Guide Footnotes 1. There is also a warming effect from the geothermal energy at the Earth’s core, but this is sufficiently small and stable that for our purposes we can ignore it. 2. Parts per million is the ratio of the number of greenhouse gas molecules to the total number of molecules of dry air. For example, 300ppm means 300 molecules of a greenhouse gas per million molecules of dry air. Strictly speaking concentrations are measured in parts per million by volume (ppmv), but this is widely abbreviated to ppm. Don’t be confused if some papers refer to ppmv. 3. Emissions are not the sole determinant of atmospheric greenhouse gas concentrations due to the Earth’s natural ‘carbon sinks’ which soak up some of our emissions. Concentrations are not the sole determinants of radiative forcing due to other forcings which will be discussed shortly. The time delay between radiative forcing and temperature increase is caused by the thermal inertia of the planet – it has great mass (with much of the heat initially being used to warm the deep oceans) and therefore takes some time to warm or cool. Of the (equilibrium) temperature increase ultimately produced by a given increase in radiative forcing, only about half manifests within 25 years, the next quarter takes 150 years to manifest, and the last quarter many centuries. 4. These illustrative graphs do not include the effects of climate feedbacks such as carbon sink degradation. Also see the MIT Climate Online 'Greenhouse Gas Emissions Simulator' 5. Figures from: IPCC AR4 Working Group I Report, Chapter 2 , Table 2.14, p. 212. More detail on GWP available at: http://en.wikipedia.org/wiki/Global_warming_potential - note that the GWP for a mixture of gases cannot be determined from the GWP of the constituent gases by any form of simple linear addition. 6. There is also a separate but related concept called Carbon Dioxide equivalent. This gives the amount of CO2 that would have the same GWP as a given amount of a given gas (or mixture of gases). It is simply calculated by multiplying the GWP of the gas by the given amount (mass) of gas. For example, over a 100 year period methane has a GWP of 25, so 1 gram of methane has a Carbon Dioxide equivalent value of 25 grams. In practice, since Carbon Dioxide equivalent is expressed as a mass (grams, tonnes etc.), and Equivalent Carbon Dioxide (CO2e) is expressed as a concentration (usually in parts per million), they are not easily confused, despite the similar names. You may also encounter references to the "carbon equivalent", especially when discussing carbon that is not in gaseous form (e.g. carbon in coal deposits). A carbon equivalent figure can be converted to carbon dioxide equivalent by multiplying by 3.644 to account for the different molecular weights (3.644 tonnes of CO2 contains 1 tonne of carbon). 7. The IPCC is the Intergovernmental Panel on Climate Change - the body established jointly by the United Nations and the World Meteorological Organisation in 1988 to assess the available scientific evidence. 8. The IPCC considered the so-called ‘Kyoto basket’ of greenhouse gases (GHGs). Under the Kyoto Protocol, signatories committed to control emissions of a ‘basket’ of six GHGs - carbon dioxide, methane, nitrous oxide, HFCs, PFCs and SF6. 455ppm figure from e.g.: IPCC AR4 Working Group III Report, Chapter 1 , p.102 The IPCC estimate of CO2e(Kyoto) is detailed by Gavin Schmidt of NASA in a post at Real Climate 9. These negative forcings include the so-called ‘global dimming’ effect. For more on this crucial consideration see: “On avoiding dangerous anthropogenic interference with the climate system: Formidable challenges ahead”, V. Ramanathan and Y. Feng, Proceedings of the National Academy of Sciences, vol. 105, 23 September 2008, pp. 14245-14250 IPCC CO2e(Total) figure: IPCC AR4 Synthesis Report, notes to Table 5.1, p.67 10. Table source: IPCC AR4 Working Group I Report, Summary for Policymakers, Figure SPM.2, p.4 11. IPCC 2005 CO2 levels: IPCC AR4 Synthesis Report, Summary for Policymakers, p. 5 12. IPCC 2001 figures: IPCC TAR Working Group I Report, Chapter 6, Table 6.7 1995/2007: IPCC AR4 Working Group I Report, Chapter 2 , Table 2.14, p. 212 13. Error ranges: IPCC AR4 Working Group III Report, Chapter 1 , p.102 14. Up-to-date measurements of atmospheric CO2 concentrations are always subject to revisions, pending recalibrations of reference gases and other quality control checks. Trends and 2008 figure taken from: NOAA Earth System Research Laboratory - Global Monitoring Division (site accessed August 2008) Pre-industrial CO2 levels from: NOAA (US National Oceanic and Atmospheric Administration) 15. See footnote [3] above for details on climate time-lags. Figure for warming from emissions to date taken from the Climate Code Red report by Carbon Equity, p.22. Also see IPCC AR4 Working Group III Report, Summary for Policymakers, Table SPM.5, p.15 for ultimate (equilibrium) warming from current atmospheric concentrations. Finally, note that a 2008 paper in the Proceedings of the National Academy of Sciences examined the impacts of air pollution (which blocks sunlight and thus reduces temperatures – the effect known as ‘global dimming’) and found that this is masking the full extent of the warming effect from greenhouse gas concentrations. Building on the IPCC’s work, the paper finds that if air pollution reduces – as it is expected to do – then 2005 atmospheric concentrations could commit us to around 2.4 degrees of warming above pre-industrial temperatures, with about 90% of this warming taking place this century. Images 1. Climate-o-meter used (in edited form) with permission from http://www.ageofstupid.net/ 2. Radiative forcing illustration used with permission from David Wasdell 3. Indicative climate graph created by author in partnership with David Wasdell, and with assistance gratefully acknowledged from Ben Brangwyn. 4. Indicative climate graph created by author in partnership with David Wasdell, and with assistance gratefully acknowledged from Ben Brangwyn. 5. Radiative forcings table from: IPCC AR4 Working Group I Report, Summary for Policymakers, Figure SPM.2, p.4 6. Indicative climate graph created by author in partnership with David Wasdell, and with assistance gratefully acknowledged from Ben Brangwyn.