(2) Degrees of existence

According to a UN Environment Programme report released yesterday, The Emissions Gap Report – Are the Copenhagen Accord Pledges Sufficient to Limit Global Warming to 2° C or 1.5° C? (summary PDF), if the planet is to have a reasonable (defined as 66%) chance of limiting warming to 2ºC, global emissions will have to peak before 2020, with emissions in 2020 of around 44 GtCO2e and reducing sharply thereafter. The report assesses the Copenhagen Accord pledges as likely to deliver best case 2020 emissions of about 49 GtCO2e. — leaving a “gap” of at least 5 GtCO2e between commitments and ambition. A “lenient” interpretation of the Accord could result in emissions little different to business as usual.

In order to close that gap, the report suggests that countries could adopt higher conditional targets, avoid the use of surplus emissions units (so-called “hot air”), and ensure strict rules for land use change and forestry carbon accounting. The good news is that the report suggests this might be possible. The bad news is that to have a reasonable chance of hitting a 1.5ºC target emissions will have to reduce by 4 – 5% per year after 2020, and move into negative (removing carbon from the atmosphere) territory after 2050. The report suggests this could be done by huge afforestation projects and using biomass energy generation with carbon capture and storage.

The UNEP report is part of the stage setting for the COP16 conference in Cancun beginning next week. More coverage at the BBC, Independent, and Guardian. Richard Black at the Beeb puts the worst case in the lead:

The promises countries have made to control carbon emissions will see temperatures rise by up to 4ºC during this century, a UN report concludes.

Ban Ki-moon was a bit more up-beat (that’s his job):

“I encourage all Parties to make good on their national mitigation pledges, and to further progress within the negotiations as well as through strengthened efforts on the ground to curb emissions. There is no time to waste. By closing the gap between the science and current ambition levels, we can seize the opportunity to usher in a new era of low-carbon prosperity and sustainable development for all.”

Sounds good. Sounds implausible. The gap between commitment and ambition is big and getting bigger by the day. Even a global recession could only trim last year’s emissions by 1.3% compared with the year before, as emissions growth in China and India more than made up for falls in the US, EU and Japan. The UNEP report suggests that there’s still a way to avoid the most damaging warming, but a look at ambitions for Cancun indicates the political will is lacking.

[Update: Barry Brook has a guest post from Tom Wigley looking at the likely climate system response to achieving zero emissions by 2050.]


38 thoughts on “(2) Degrees of existence”

    1. You are, Nick. But the emissions pathways which go negative don’t do so until after 2050, so presumably it’s thought large scale CCS will be working by then (or perhaps cost will be no object).

    2. The problem with coal is that it is a cheap but dirty fuel. For every ton of of coal you get two tons of CO2. To capture and dispose of that amount of CO2 is very expensive, consequently unpopular.

  1. Dear Gareth

    I tried to send this to you vai the website’s contact function but it didn’t seem to work anyhow.

    Dear Gareth

    I attach a notification of a test screening of a movie on climate change called Thin Ice. The test screening is in San Francisco but the film will be completed by end of February, 2011, and screened in Wellington in March in the lead up to the Climate Change Research Institute Forum – Climate Futures-Pathways for Society 31 March-1 April, Te Papa.

    Sunday, 12 December 2010, 6:30pm – 8:00pm
    Location: San Franciso – Moscone Center South – Esplanade Level Room 300
    Admission free – but e-mail thin-ice@vuw.ac.nz with name/address for the limited seats available

    Today it seems as if climate science has come under sustained attack, recently approaching flashpoint. Simon Lamb, geologist and filmmaker, decided to take his camera and find out what was really going on from his climate science colleagues, with support from both Oxford University, UK, and Victoria University of Wellington.

    Over three years Simon filmed stunning footage in the Arctic, Antarctic, Southern Ocean, New Zealand, Europe and the USA with scientists from a wide range of disciplines. They talk about their work, their hopes and fears with a rare candour and directness. This creates an intimate portrait of the global community of researchers racing to understand our planet’s changing climate, and provides a compelling case for rising CO2 as the main cause.

    The film is being edited with the help of David Sington of DOX Productions, who was honored by the AGU in 1999 with the Walter Sullivan Award for Excellence in Science Journalism; his previous feature documentary “In the Shadow of the Moon” was a world-wide hit.

    This is a test screening of work in progress. We will ask the audience for a brief written response before leaving.

    regards Doug

    1. Thanks Doug. I’ll see if I can get in touch with Simon. I’ll be posting more about the CCRI forum you mention — not least because I’ve been invited to take part… 😉

  2. Can i ask a question?

    I read somewhere that a quarter of all human emissions have occurred in the past 10 years and yet the temp has barely moved. What evidence is there to support statements that suggest the temp will go up by X if emissions continue to rise?

    1. Oceans take a long time to heat up — roughly 30 – 40 years for the top layer to reach thermal equilibrium. So current temps (which have more than “barely moved” in the last ten years) could be said to result from GHG levels in the 70s and 80s. The full warming we’ll get from 389 ppm CO2 won’t be apparent until 2040/50. This is not comforting news.

      1. Sorry Gareth but your response does not answer my question.

        Are you now saying there is a 40 to 50 year lag between CO2 increases and temperature increases?

        Lets leave personal opinions behind here and look at the facts.

        RSS shows the temp has risen by 0.1C per decade since 2000 and UAH show it has risen by 0.6C the mean of both is 0.3C per decade therefore i think it is safe to say the temps have barely moved.

        Josh Willis said in March 2008: “There has been a very slight cooling, but not anything really

        These two events led Kevin Trenberth to describe the missing heat as a travesty, he was then forced to change his theory about heat distribution in the atmosphere and oceans and now claims all the heat has dived down to the bottom of the Mariana trench. Unfortunately for us the ARGO bouys did not measure this heat as it traversed from the atmosphere to the deepest oceans.

        So we know our theory dictates there must be more heat but we have no idea where it is, is it possible our theory is wrong and the missing heat does not in fact exist?

        Which leads me back to my original question, what evidence do we have that supports statements like “if we reduce CO2 by X then we can control the temp to X or words to that effect?

        1. Are you now saying there is a 40 to 50 year lag between CO2 increases and temperature increases?

          No. Read what I wrote. It takes 30-40 years for the top layers of the ocean to reach thermal equilibrium for any given level of atmospheric GHGs. It takes that long for the system to “catch up”, because it takes a lot of heat to warm the ocean, and there’s a lot of ocean to warm. In other words, if we were somehow able to freeze atmospheric GHGs at today’s levels, warming would continue for at least another 30-40 years. Read the BNC post in my update above to get an idea of the various time constants in the climate system.

          So: you can’t look at temps over the last ten years and draw any conclusions about GHG forcing, except to note (as sailrick points out) warming continues.

          Looks like you need to read up on what Trenberth’s “travesty” quote was about.

          1. I am well aware of the context in which trenberth made the statement but in the end he has now idea where the missing heat is so he blames inadequate measuring.

            So if we go back to my original question, if we are pumping out more and more CO2 and the air temps have barely risen like Trenberth says and the oceans (top 900 meters) have cooled slightly like Willis says and our only explanation for the missing heat is based on an assumption that it is at the bottom of the Mariana trench where we cannot measure it then “how do we know that if we reduce CO2 by X then we will reduce the temp by X”.

            I am not interested in hearing guesses or opinions or hunches i want to know what evidence there is that shows if we reduce CO2 by X the temp will reduce by X in response. When you consider the science is settled I do not believe i am asking too much here.

            1. What’s settled is that if we add GHGs to the atmosphere, the planet will warm. How much, and by when are legitimate questions. Therefore reducing atmospheric GHGs will cool the planet (eventually). Read the reference I provided to the BNC post by Tom Wigley. You’ll see there that even if we manage to get to zero emissions by 2050, global average temperatures will not fall to current levels until the next century (and sea level will carry on rising well beyond that).

              Ocean cooling? Only if you confuse the short term with the long.

              Now, if you want argue about climate sensitivity, that’s something else again — and the last ten years does not provide any useful information about that.

            2. “What’s settled is that if we add GHGs to the atmosphere, the planet will warm”

              The only bit which is settled is that CO2 as a ghg only adds 1.2 degrees (according to James Hansen anyway) but the other 2-6 degrees PREDICTED AND NOT YET OBSERVED is supposedly to come from positive feed back causing radiative forcing and therefore more energy/heat.
              That part has yet to be proved by observation. But of course this “extra” warming is the part which is supposedly going to melt our Ice.

            3. Warmer atmosphere holds more water – has been observed. Read up on Clausius-Clapeyron. Expected, observed, contributing to current warming.

              Detailed discussion of climate sensitivity here — see especially the summary graph from Knutti and Hegerl 2008.

    2. The temp rise is related to CO2 concentrations. And that relationship is logarithmic.

      Emissions tend to go half and half into ocean and atmosphere so only half (very approx) has gone into the atmosphere. Concentration is rising at 2+ ppmv per annum, and that rate _is_ rising a bit. And nothing happens quickly, days, months, years, in such a large system. Which also has its own rhythms ENSO etc on which this effect is superimposed.

      Temperatures are rising and the 10 year trends are not very pretty. Neither are the 30 year trends. The 100 year trend is pretty unequivocal.

      Seeing as we’re nearing the end of the hottest decade ever recorded, I’m not sure what you’re referring to when you say “the temp has barely moved”. We’re now at 308 consecutive months above the 20th century temperature average – the last month below this average was in 1985.

      1. Adelaidy,

        The 30 year trend 1970-2000 was 1.5C/century

        The 30 year trend from 1860-1880 was 1.6C/century

        The 30 year trend from 1910-1940 was 1.5C/century

        And FYI the 30 year trend from 1980-2010 is 1.5C/century

        So IF the co2 concentration in the atmosphere is constantly rising then why are the trends remaining constant? So far both Gareth and yourself have responded with opinions, what i am after is evidence based reasoning which shows if co2 continues to rise the temp will go up by X, if we reduce co2 temp will go down by X.

        1. “… if co2 continues to rise the temp will go up by X, if we reduce co2 temp will go down by X.” But not next week, next year or next decade.

          Reducing CO2 emissions will reduce the rate of temperature increases. Ceasing all emissions will slow the increase even more. Maintaining nil or near nil emissions from geological carbon will, eventually, see temperatures actually fall, probably at much the same rate as they rose. The hard truth is that it’s not like turning off a burner on a stove. We have to reduce emissions now in order to prevent our grandchildren and their grandchildren from the worst harmful effects.

          I will be dead before 2050, I don’t expect to see significant benefit in terms of temperature, drought, flood, ice melt or SLR before I go. I do hope to see good numbers showing that the matter is under control by then.

          In fact, my personal fantasy is that modern society will have moved towards something a bit like The Jetsons (minus the flying cars). A society with invisible, silent, unlimited power for all manner of technological whizz-bang activities I couldn’t have dreamt of when I was a child.

          1. Adelaidy,

            You may aswell have quoted the front cover of the latest WWF brouchure, what you have just said is based on your opinion. I want you to produce empirical evidence that shows you to be correct.

            So once again, if CO2 is reduced by X how much will the temp be reduced? I dont want opinions i want facts. Am i asking too much?

            1. Why the aggressive tone, when you could have done the searching work yourself instead of demanding others to it?

              Your question is a long shot from being novel. For instance, go to the IPCC website and look for emission scenarios, their outcomes and discussions in the AR4 WG1 report.

            2. But too understand the facts you must understand the physics of the situation. Adelady and Gareth have pointed out some points which might help you in this regard and to help you avoid jumping to a wrong conclusion. What you are asking could be found in any climate textbook. Frankly, you don’t seem that interested in understanding the matter – more likely you are just a Denier Troll copying the tactic seen in the likes of Plimer’s book, where at the start of very chapter he lists “facts” , which on the face of it are “true” , but always these have some very big “buts” or are irrelevant to the case for AGW.

            3. Crakar is a hardened contrarian on other blogs. He’s not trying to find out anything, he’s trolling and looking to score the usual debating points.

            4. This may be true, John, but I’ll give him the benefit of the doubt — at least for the time being.

            5. Craker24, earlier in your questions you mentioned the old litany that somehow in the past 10 years the climate is said to have cooled.
              The 11 year solar cycle – we are just coming out of what has been a rather deep minimum – is varying the solar output by about the same amount as the climate forcing of 7 years worth of CO2 increases. In other words a reasonable amount of the climate forcing due to CO2 over the last years has been masked by the low in the solar cycle.
              Despite this though the last decade was the warmest on record and 2010 ties with 2005 as the warmest on record.
              So it is fair to say that we will likely see the opposite effect in the next 5 years where the rising solar output on the up side of the solar cycle coincides with the rising CO2 forcing.
              If you look at many other trends such as the arctic ice volume decline you can see many other areas where heat energy has gone which perhaps has not yet been accounted properly too.
              And once we have a summer ice free arctic this alone will cause a significant further warming due the albedo effect.

            6. cynicus,

              I have looked at the IPCC reports and am still left wondering i was hoping someone here could explain it but alas it is not to be.

              Richard T,

              Chimes in with name calling (troll) what i am asking for is not found in “just any climate text book”. If i increase CO2 then in theory the temp will rise but the rise from CO2 is very, very small the predicted rise of 6 to over 8C by 2100 will be mostly provided by the increase in water vapour.

              But it is not that simple first of all WV has to increase at the predicted rate and secondly the sensitivity the climate shows to this increase has to be correct also.

              The IPCC claim this sensitivity to be very high however they do not provide empirical evidence to support this claim but instead supply computer simulations.

              Many scientists put a double of CO2 at less than one degree now i am not suggesting they are correct but there is a big difference between 0.5C and 8C especially when you consider the lack of real world empirical evidence to support. So now the answers i seek are not found in text books as they are not found in the IPCC.


              This would be about my tenth post here and you now claim i am a contrarian troll and a hardened one at that (sorry no prizes for second). The fact that you would respond in such away instead of progressing the debate speaks volumes. By the way i am flattered that you claim i troll the internet inferring that i am famous in some way. I would like to return the compliment but….sorry i have never seen nor heard of you.


              Let me stop you at your first sentence, go back and re read what i have said. I have never at anytime made the claim that the temps have dropped in the past ten years.

              RE solar output i must dissagree the sun was burning at its most brightest for the past 11,000 years in the late 90’s but yet the IPCC claimed the total solar insolation (TSI) had barely changed thus TSI changes had very little effect on climate. The solar min we are having/had now may have been longer than usual but the TSI has once again barely changed. All other outputs from the sun are considered not worthy of discussion according to the IPCC.

              I dont want to get side tracked from my original question but i suspect my welcome here is well and truly worn out so here goes.

              Arctic ice, once we get a summer free arctic? Are you making a prediction? Please deal with facts not your reality based on opinions.

              The albeado from the Arctic is quite small as it is in darkness for 6 months and the other 6 the angle of approach by light is quite low so it does not have the effect you beleive it has. Whilst on the subject of ice the total amount of ice on the Planet has not moved (greenland,Arctic,Antarctic) for decades but yet you calims all the heat is melting the ice. Next thing you are going to tell me is that AGW only works in the Arctic because of some comvoluted ad hoc theory about the antarctic.

              So let me just say it is a sad day when people need to look at local events for signs of AGW.

              In summary i came here to ask a question of where is the evidence the planet will experience climate disruption etc. I got toask my question several times but no one here could answer, sure i got anecdotes and opinions but not answers so in the end some people here were forced to resort to the tired but true method of name calling.

              Thanks Gareth its been fun all the best to you all.

            7. Well, if you’re not coming back, I won’t bother explaining why you’re wrong in just about everything you say.

              Looks like JohnMM was on the money…

            8. Never mind that craker is gone but for those who would like to test his proclamations about the TSI being higher in the 90ies than in the past 11,000 years… well lets go to the source then, in particular the reconstruction back to 1880 on the bottom of the NASA page linked to below. Not sure where craker gets his 11,000 year data from as he omitted references…

  3. “I read somewhere that a quarter of all human emissions have occurred in the past 10 years and yet the temp has barely moved. What evidence is there to support statements that suggest the temp will go up by X if emissions continue to rise?”

    A lot of things are said “somewhere”. Especially pertaining to climate change.

    Here are some articles on supposed cooling in the last decade




    There are many others, some more up to date. See Skeptical science on this also.
    Every year since 2001 has been warmer than any year in the instrument records.

    Preliminary Oct 2010 Global temps – NOAA State of the Climate

    “For January-October 2010, the global combined land and ocean surface temperature was 0.63°C (1.13°F) above the 20th century average of 14.1°C (57.4°F) and
    Tied With 1998 as the Warmest January-October Period on Record.

    The global average land surface temperature for the period January-October was the second warmest on record, behind 2007.

    The global average ocean surface temperature for the period January-October tied with 2003 as the second warmest on record, behind 1998. ”

    1998 was the biggest El Nino in a century, making it an outlier, or large anomaly. That’s why skeptics like to cherry pick it as a starting point for comparison with 2008 for instance, which was the opposite, a La Nina year.
    There was an El Nino this year, but nothing like 1998, or 1982-83 for that matter.

  4. Good background reading
    How do human CO2 emissions compare to natural CO2 emissions?

    Skeptical Science is, in my opinion, the best place for laymen to become better informed about climate change.
    on supposed cooling –

    As for your question about how predictions of temp increase from CO2 emissions are made:
    A detailed look at climate sensitivity
    Debunking the dangerous anti-science fantasy of the ‘lukewarmers’
    September 19, 2010 posted from Skeptical Science


  5. My first comment has a typo.
    “Every year since 2001 has been warmer than any year in the instrument records.”

    Should read:
    Every year since 2001 has been warmer than any year in the instrument records, prior to 1998.

  6. Tom Wigley has a piece here http://bravenewclimate.com/2010/11/24/effect-zero-co2-2050/ which concludes that an emissions scenario of a linear reduction of GHG emissions to zero from 2020 to 2050 would lead to a most likely global temperature increase of 1.7C above pre-industrial levels. There are also some interesting projections of long term climate response in such a scenario.

    Of course the probability of achieving zero emissions by 2050 currently looks very small, so this is a limit case and unfortunately has little connection with what looks most likely to happen.

  7. Gareth: What coverage of Cancun do you have planned? Are you doing a preview and updates as the summit goes? What can we expect from the UNFCCC to set the scene for next years ETS review?

    1. I’m planning to carry some of Barry Coates’ (Oxfam NZ) on the spot reports, and I hope we’ll be able to interview him in Mexico for the next Climate Show. Plus I’ll probably do a little scene-setting post early next week.

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