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Possible unease over climate model stretching

Susan Watts | 11:24 UK time, Thursday, 18 June 2009

There is a big government launch on Thursday of research showing the possible impacts of climate change here in the UK, looking out towards the end of the century.

It is Environment Secretary Hilary Benn's day. His aim is to show us all what might lay ahead for our children, depending on how successful we are at cutting back greenhouse gas emissions.

Some might say to "worry" us into changing our behaviour.

This is an update on similar research from seven years ago, both spearheaded by the Hadley Centre's climate change team.

This time round there will be an interactive website for consumers, so we can all find out about the likely warmer, wetter winters or hotter, drier summers where we live.

The scientists have apparently divided up the UK into a grid of 25km (16 mile) squares.

The only trouble is that by offering up such a fine grid as this, instead of the region-by-region break down of 2002, there is necessarily less certainty about the changes that might be felt in each square.

The head of climate change at the Hadley Centre, Vicky Pope, tells me this larger uncertainty is "reflected" in the results.

She may find she struggles to get this across later on Thursday.

She told me the grid is designed to help satisfy "users", such as insurers who deal in say the risk of extra flooding, or local planners deciding where to build schools and hospitals.

But she also concedes that using climate models in this way necessarily stretches them as far as they can: "so there will be some unease", she says.

There may be even more unease tomorrow, when the Environment Agency publishes its strategy on current flood risks, and what it is going to cost to cope with climate change.


  • Comment number 1.


    Relax - I shall tire of trying to present science as open minded enquiry long before The Science Establishment (on whom media rely) ever sheds dogma and the Peer Review 'outer defences'.

    Climate 'science' is not good science. Add the enduring (but false) notion that weather is Earth-generated, with no input from inner space (let alone outer), and you have bad science with a cherry on top.

    Read all there is on lightning (an acknowledged weather phenomenon) and it will lead you into space (riding a 'Sprite') - electrically active space. Then read all you can on the Sun (a lot will be contentious, but you will find electricity and magnetism plentiful. Put the Earth 'near' the sun and wonder about electrical flows and their effect on electric weather AND OTHER POSSIBILITIES. How am I doing? Oh - did I forget to mention searching 'Electric Universe'? Ponder - but believe nothing; now you are doing good science.

  • Comment number 2.

    The sad thing is it will take a major catastrophe clearly resulting from man made pollution for any real moves to be made, by which time of course it will be too late. The recession will have a lasting effect on capitalism but maybe more on the climate change.
    As is shown on website the worlds problems were created by engineered objects and can only be improved by being re-engineered to vastly higher standards incorporating all of the latest technology. With the US having a total energy budget of 70 trillion the sums required would make the bank bailouts pale in insignificance.
    The increase in demand far outweighs the reduction so we really need to accept the inevitable.

  • Comment number 3.

    All very tricky. And one I don't envy the various 'powers that be', what with the massive authority, moral, trust and every other-wise that they currently enjoy with the (growing, but let's not worry about that) population.

    I am just not sure that trying to unease the public into things slowly is quite working on past and present evidence, and when every flurry of climate foreboding is often followed by loooong fallow periods where navels get gazed at and economies get weighed (especially in terms of getting re-elected), if can often come across as tokenistic at best, half... um.. considered or, worse, when taxes heave into view, a tad opportunistic.

    I must say that following what has doubtless been a very thorough briefing, that even as supportive a medium as the state broadcaster is littering its latest report with a preponderance of qualifying "quote" marks on every claim is hardly encouraging. Especially on top of the "might's" and "depending's". The only certainties seem to be that as the grids get smaller, the derriere-covering gets greater. And, IMHO, that negates the whole exercise.

    And if eyebrows are cranking here, I can only imagine what they will be like in some media, and how that will in turn be absorbed by some a wee bit preoccupied paying their Mum's annual care bills with less than certain leaders by example reckon is needed annually to sort out swirly ceilings, house ducks or faux timber their 50" TV rooms. Or certain quango senior execs still seem to score mega-bonuses for when what they are supposed to be doing fails and they try and blame the consequences of blocked drains or concreting over greenfields on a bit of weather.

    At least Mr. Benn can hold his head high in this regard, but whether a disenchanted, distracted public will notice the distinction is doubtful.

    ps: When it says 'on Thursday' on a blog dated Thursday, can I presume we are talking a weeks' time for the launch of this "research"?

  • Comment number 4.

    Electric Universe...? As in Magnoflux tunnels within an electric universe? :D That brings back memories. :) The original website got rated ILLUCID when I submitted it to after its author posted something about it in the old BBC S&N message boards. That was an age of innocence for me: good science discussions, the weekly moan about Horizon, James Avey's Jules Vernesque patented FTL spaceship and various other mostly entertaining and harmless bits of crackpottery. Few if any of those vile parasitical medical cranks and quacks and their lawyers, IIRC.

    Anyway, that's really why I'm nosing around in here this morning - I just came to see if the BBC had noticed yet that there is a war on. Apparently not. ;-)

  • Comment number 5.

    There are two things we need to do to keep our planet a place where we can live.
    1. limit the world population
    2. set a carbon budget per person; not the same in each country but we must get away from the current principal that the rich can pollute as much as they want while everone else can polute only what they can afford. The rich will have the house on the hill and the poor will be on the flood plain. No prizes for guessing who is going to lose everything including their life as the temperature and seas rise.

  • Comment number 6.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • Comment number 7.

    Hadley predictions: CO2 parts per million.
    The UK government (Hadley Centre) has announced temperature predictions for 2010-2060 based on 12 different climate models. They state that their central estimate for temperature increase over 50 years (2010-2060) is 2 deg.cent. The figure applies to the entire UK area and is essentially a global estimate or at least a northern hemisphere effect. The Hadley centre states that the land carbon cycle is expected to become less efficient at absorbing CO2 as the climate warms and that this area of science has substantial uncertainty. Here is an e-mail from the centre in which they accept that it is not so much increasing industrial emissions of CO2 but the ability of the biosphere to absorb CO2 that will account for increased C02 ppm in future:
    The rate of growth in atmospheric CO2 concentration depends on future fossil fuel usage, and on the ability of the biosphere to absorb CO2. The IPCC SRES scenarios used for UKCP09 all predict emissions of CO2 to increase during the first half of the 21st century, while the land carbon cycle is expected to become less efficient at absorbing CO2 as the climate warms. Consequently, the rate of CO2 build up in the atmosphere over the next 50 years is projected to be higher than in the recent past. There is still substantial uncertainty in the strength of feedbacks between climate and the carbon cycle that determine CO2 uptake, so the UKCP09 projections sample a range of land carbon cycles consistent with current understanding. For the SRES A1B scenario the projected median value for mean atmospheric CO2 concentration for the period 2050-2070 is 600 ppmV. The projected 10-90% range for this period is 520-650 ppmV with A1B forcing. More detailed analysis will be presented in future publications from the Met Office Hadley Centre.

    Enquiries Officer
    UK Climate Impacts Programme
    School of Geography and Environment.

    When one takes a closer look at the predictions, one sees that it is difficult to account for an increase of this magnitude in terms of CO2 emissions alone. The Hadley estimates for 2010-2060 appear to be based on uncertain theoretical models and computer predictions about secondary greenhouse effects other than CO2 such as methane, aerosol pollutants and water vapour etc. Society is being asked to make reductions in carbon usage, even though fossil fuel itself is not necessarily the actual culprit. It is important to keep the public well informed about all the alleged causes of global warming.
    The following graphic shows an increase in atmospheric CO2 parts per million for 1960-2000 of 50. It is a simple linear function and one can therefore use simple extrapolation to estimate a figure for the increase in atmospheric CO2 parts per million of 125 per 100 years. Taking a current value of 390 CO2 ppm for 2010 and taking 1760 as the base year for the pre-industrial initial state of CO2 ppm =280, one might thus estimate cumulative atmospheric CO2 as follows:

    1760 280 ppm approx.
    1960 340 ppm approx.
    2010 390 ppm approx.
    2060 450 ppm approx.
    2110 515 ppm approx.
    2145 560 ppm approx.

    (These atmospheric CO2 figures will be used later to estimate temperature increases (see below. N.B. There is not complete consistency in these numbers due to different estimating rules).
    These estimates of future cumulative CO2 emissions for the period 2010-2145 are essentially calculations about the path of future economic growth, particularly in China and India, that would have been provided to the Hadley Centre (Met.Office) by an outside source.
    By contrast, the Hadley centre predicts that CO2 ppm increase for 2010- 2060 will be up from the current level of 390 ppm to 600 CO2 ppm in 2060, far more than suggested above. Can CO2 ppm really grow more than 210 in 50 years? This is only possible if non-fossil fuel feedbacks, such as methane and falls in aerosol pollution, deforestation etc. account for 2/3 of the increase in CO2 ppm. According to the centre most of the increase in CO2 ppm is thus due to changes in the ability of the biosphere to absorb CO2 as the climate warms (i.e. feedbacks).
    Although the Hadley Centre claims that future CO2 ppm increase is not simply linear, reality shows that carbon intensivity per unit of GDP is falling naturally in USA and EU. Russia, an example par excellence of an old smoke-stack economy, is the country with the highest carbon intensivity per unit of GDP in the world.
    It is doubly difficult to see how atmospheric CO2 alone could account for a 2c. increase over the next 50 years in view of the following fact:
    "...This means that a doubling of CO2 from a different value (say, from the present value or from 560 ppm) gives the same forcing as a doubling from 280 ppm. But the response of the climate system, of course, could differ somewhat for different initial states, which is why doubling from 280 ppm should be included in any exact definition..." Stefan Ramhstorf, member of IPCC.
    In other words, the marginal rate of CO2 temperature effect is falling. Increased quantities of CO2 emission have a diminishing greenhouse effect. Therefore, future economic growth is less polluting than past economic growth. Increased levels of atmospheric CO2 will have a very diminished temperature effect beyond 560 p.p.m. So one must establish the saturation level of atmospheric CO2 p.p.m. at which the temperature effect becomes negligible. This is the level at which carbon use is pollution-free. And specifically, in the range where we are today, a doubling of CO2 from the current level of 390 ppm to 780 ppm would have temperature effect of 3c.+/-1.
    Hadley predictions: Temperature Increases.
    The basic historical model of the CO2 greenhouse effect is that, starting from the initial pre-industrial level of 280 p.p.m. of atmospheric CO2, a doubling from 280 ppm to 560 ppm has a temperature effect of 3c +/- 1. Leaving aside other factors such as the methane effect, aerosols and claims about water vapour and applying this greenhouse effect for CO2 to the above estimates of future levels of atmospheric CO2, one can make the following alternative estimates of future temperature increase, based on CO2 emissions alone:

    For: the period 2010-2060 (390 ppm to 450 ppm) = 60 increase in CO2 ppm
    At 3c (per doubling of CO2):= 0.64 deg.cent increase.
    At 4c (per doubling of CO2):= 0.857 deg.cent increase.

    These values are below the range of the Hadley estimates. If CO2 were the major cause of global warming, the 2c temperature increase that is proposed by the Hadley Centre would require a CO2 ppm increase in the order of 140 ppm over 50 years. This is scarcely a probable estimate on the basis of likely future economic development.


    from 2010 to 2145 (390 ppm to 560 ppm) = 170 increase in CO2 ppm.
    At 3c (per doubling of CO2):= 1.82 deg.cent increase.
    At 4c (per doubling of CO2):= 2.428 deg.cent increase.

    For convenience one may use 1760 as a base year for the start of industrial activity and subsequent human influence on the atmosphere. My understanding is that human activity caused 1c. temperature increase over 1760-1960 and a further 0.5c. increase over 1960-2010. The rate of temperature increase in the period 1960-2010 was thus already 2 times greater than the rate for 1760-1960. The Hadley centre now predicts a further 2c. temperature increase making a total increase of 3.5c. for the period 1760-2060. The UK government is suggesting that CO2 ppm increase for 2010- 2060 will be up from the current level of 390 ppm to well in excess of 600 CO2 ppm. Can CO2 ppm really grow more than 210 in 50 years? This is only possible if non-fossil fuel effects and feedbacks account for 2/3 of the increase in CO2 ppm.

  • Comment number 8.


    The government has a policy of switching to a low carbon economy. However, the advice it gets from its own advisers is:
    1.The direct effect of burning fossil fuel on atmospheric CO2 is quite small, about 25%-35%.
    2.There are many causes of increased atmospheric CO2 that have nothing to do with burning fossil fuel. An increase in solar activity or cutting down a large amount of rain forest could cause increase atmospheric CO2. The science is highly uncertain.
    3. There are also causes of temperature increase, other than atmospheric CO2, such as methane, water vapour etc. The science is highly uncertain.
    4. Increasing quantities of atmospheric CO2 have a diminishing temperature/greenhouse effect. Therefore, future economic growth is less polluting than past economic growth. So one can establish the saturation level of atmospheric CO2 p.p.m. at which carbon use is pollution-free.

    The government is in a position to question its own policy, if it chooses to do so.

  • Comment number 9.

    Land-based Climate and Temperature: A Risk Assessment.
    There is little doubt that human activity is having a perceptible effect on the atmosphere. Atmospheric CO2 is today at 390 parts per million. In the 500,000 years prior to modern industrialisation atmospheric CO2 fluctuated in a stable range between 200 and 280 ppm. A continuous increase has occurred since 1750. However, there is legitimate doubt whether the planet is warming; this depends on what time-frame and what section of the graph one looks at. Temperatures have been increasing during the industrial period but this may be part of an underlying natural fluctuation. Temperatures have also been rising continuously since the last Ice Age. It is therefore difficult to reach firm conclusions about man-made effects on the basis of relatively small temperature increases in the last 250 years. There has been rather firmer evidence of climate change in recent years, namely in the form of the diminution of glaciers in the northern hemisphere. Glaciers are a sensitive indicator of climate change- the canaries in the coal mine. Overall the changes so far have been very minor. On balance it is probable that human activity affects the global climate in a minor fashion. Climate change is not a significant threat for most areas of the world. When the economic and agricultural effects are properly assessed, climate change may be beneficial for some countries. In the U.K. climatic change is benign across all temperatures under consideration.

    Sea level: Greenland.
    Catastrophic danger could only come from melting of land based ice cap because melting sea ice does not significantly raise sea levels. The Greenland Ice cap is less stable than the Ice cap in the southern hemisphere. It is known that Vikings farmed in Greenland 1000 years ago. The preponderance of landmass in the northern hemisphere makes climate and temperature in the northern hemisphere relatively volatile. If the Greenland ice cap melted completely, it could raise sea levels by 7 metres. A possible time-frame for such an event might be 500 and 2000 years. This is a worst-case scenario. Sea levels have been rising at a rate of 20 cm per 100 years since 1600 AD, with no discernable increase in the industrial period 1775-1975 AD. During this time there has been a large amount of coastal land reclamation in countries such as Holland. Data based on the last 30 years, since 1975, suggest that sea level is now rising at 35 cm per 100 years. More than half the worlds large cities could be flooded if sea levels rose 7 metres. However, 2000 years gives the world a long time for preparation. Technology will improve more than we expect. Venice is sinking into the sea because it was built using 12th century technology, not because of any rise in sea levels.

    Sea level: Antarctica.
    The Southern hemisphere is cooler and more stable than the northern hemisphere. If Antarctica were towed into the middle of the Pacific, it would certainly melt; but it is fortunate for humans that a continent sits directly over one of the poles. Ice is held in a stable environment where it receives a minimum of solar energy. Ocean currents cannot transfer energy to land based ice and thereby cause melting. If one drills 40 kilometers below the Antarctic, there is and always has been hot earth mantle at a temperature of 400 degrees cent. The ice has been stable on this continental land mass for millennia. There is 15 million cubic kilometres or more of ice on Antarctica. Common sense tells us that a change of 5 degrees in air temperature could not cause such a large melt-down. If the Antarctic ice cap melted completely, it could raise sea levels by 60 metres. This will not happen.
    The arbitrary distribution of landmass has a large effect on climate. When the Isthmus of Panama formed 5 million years ago, it divided the circulation of a single large tropical ocean and the Atlantic Ocean formed. The entire planet has cooled as a result of these events. The situation of Antarctica directly above the pole also has a large cooling effect that outweighs any effects of increased atmospheric CO2.
    Finally, the Ice cap is dynamic. It is constantly being added to by snow fall and glacier formation. It lies on a terrain of valleys and mountains that give rise to large stresses. The curvature of the earth is compressed several kilometres by the weight of ice in Antarctica. At the periphery of such a system bits of ice cap will break off and form icebergs as part of a release of energy. This is known as calving The dynamics of continental ice caps are far from understood. Increases in the rate of iceberg formation or changes in stability do not necessarily represent structural changes resulting from temperature increases. Nor do they signify an imminent rise in sea levels. The current interest in Antarctica amongst climatologists is largely fuelled by self-interest and ideology. They make a living from exaggerating the dangers and pandering to the wishes of their political masters.

  • Comment number 10.

    Here, for those not blind to read anything that doesn't kill their prejudice, is an example of how denialists refuse to change and how the self-proclamation of "skeptic" is not justified.

    On being asked what would convince two self-proclaimed skeptics (and I see we have a few here...) to agree AGW is real, they said a decade of warming.

    After this was shown (see below), nothing happened.

    Apparently that was not enough to convince them, despite the decade being one that some here have claimed is a cooling period.

    "What would convince me in AGW is a rise in global temperatures over the next decade."


    From the hadley data that Jack used to "prove" it was cooling, the anomaly average for the last 10 years is:


    The anomaly average for the 10 years previous to that is


    Therefore this decade is warmer than the previous decade.

    I take it you both will now be convinced of AGW.

    You can check the data here:

  • Comment number 11.

    This comment was removed because the moderators found it broke the house rules. Explain.



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