Long range forecasting is accurate and CO2 does cause global warming

Scientists have been responding to claims that if they were unable to predict the bad weather how can they predict climate change over the next century?

Scientists have been responding to claims that if they were unable, a few weeks ago, to accurately predict the severe weather that has hit Britain over the past few days, how are they able to accurately predict climate change over the course of the next century?

Speaking on last night’s Newsnight, Dr Patrick McSharry, research scientist at the Smith School at Oxford University, explained that there is a “big difference” between short-term weather forecasts and long range climate forecasting.

He said:

“It is very much in the scientists’ position to actually show that there’s a big difference between forecasting weather and then forecasting climate change, totally different model, totally different timescales, totally different areas of the globe.


“If you look at the actual scientific details of what’s been attempted to be calculated there is a huge difference. Before someone generates a forecast they have to validate the model, they have to make sure it adds up to being able to predict the historical events that have gone beforehand and if it’s able to do that then you have some confidence that it will actually work into the future.”

Keith Groves, Director of Operations at the Met Office, added that global warming can only have come from carbon dioxide:

“We do validate our climate models. To actually reproduce the change in temperature that we’ve seen in the last 100 years, the only way you can do that is by adding carbon dioxide into the model, so we have real confidence in the skill of our climate model to replicate the global climate as we move forward.

“That’s completely different to trying to forecast the variability on one month or two month or a season ahead. It’s a completely different application of the science.

30 Responses to “Long range forecasting is accurate and CO2 does cause global warming”

  1. Guido Fawkes

    Bet you £100 you can’t tell me if we are we going to have an above average or below average summer for both temperature and rainfall?

    That should be easy.

  2. hmmm

    Not that I doubt you, but what evidence is there that long-term forecasting is accurate? What predictions did they made 20 years ago about the climate, and were they right?

    I find it increasingly plausible that these scientists just aren’t very good at their jobs. The very best scientists seem to go into theoretical physics or nanotechnology, because that is where the forefront of human knowledge is. I’m sure the meteorologists are moderately competent but they aren’t going to be the finest minds of our generation, really.

  3. Shamik Das

    Gentlemen, many thanks for your comments. Guido, what do you think will happen?

    “hmmm”, the models they’re using to predict the next 100 years accurately predicted the previous century, when applied to the data that would have been available to them in 1900. They are extremely talented individuals.

  4. harry

    “We do validate our climate models. To actually reproduce the change in temperature that we’ve seen in the last 100 years, the only way you can do that is by adding carbon dioxide into the model, so we have real confidence in the skill of our climate model to replicate the global climate as we move forward.”

    or the last 100 years warming could be due to something else. like natural cycles, ocean currents etc.

    the problem with these models is that they have 1000 variables and only 1 dataset to check against. i could make a climate model show the last 100 years temperatures as a silhouette of the taj mahal if i could be bothered.

    “Give me four parameters and I can fit an elephant.
    Give me five and I can wag its tail” — (The source? Variants have been attributed to C.F. Gauss, Niels Bohr, Lord Kelvin, Enrico Fermi.)

  5. hmmm

    Shamik Das, I think the credit crunch showed what good computer models are. Exotic derivatives were basically priced using computer models. They made a bad assumption and it all fell down.

    Accurately modelling the past is useless – it misses any changes since. Having accurately modelled the current before it happened is much more credible, though it can still miss the black swan. And yes, I reckon there can be black swans in climate as well as weather.

    I want to know what they DID, not what they are DOING.

    For what it’s worth, I believe wholeheartedly in tackling climate change, especially when doing so will have ancillary benefits like energy security. Though I don’t think the Copenhagen summit was the right way to do it at all. That was just a circus, more for politicians than politics.

  6. Oxford Kevin

    hmmmm are you are talking about meteorologists who do weather measurements and weather forecasting or climatologists who study the climate?

  7. hmmm

    Shamik, what evidence do you have that they are extremely talented individuals?

    I just don’t believe it.

    Who is the Edward Witten of climate science?

    I just don’t see climate science as being more intellectually stimulating for the best minds in the world as other scientific vocations. Evidence, please.

  8. Oxford Kevin

    hmmm, since you made the claim, I believe the onus is on you to provide the evidence. So far it just seems to be your belief.

  9. hmmm

    Oxford Kevin,

    Firstly, the onus, speaking sociologically, isn’t on me – scientists have to prove their credentials all the time.

    Secondly, the onus, statistically, isn’t on me. I assume that you have taken statistics courses at A-Level or above. If so, you should have a basic understanding of how to choose H_0 – and if you think about it, you will see why you made the wrong choice.

    Secondly I can’t. My evidence is anecdotal, though I spent many years in a scientific role in academia, including at top universities, and I know who I rated amongst the faculty.

    I have no question that they are doing is reasonable science, but in general, it is fairly mediocre. That’s my opinion, not fact. It can’t be any other way.

    That’s not to say it shouldn’t be done, or funded. All I’m saying is that it isn’t the most intellectually demanding science (in my opinion) and therefore the best graduate students will go elsewhere, because above all, they crave intellectual stimulation.

  10. Oxford Kevin

    Thanks for clarifying that it is just your opinion.

  11. hmmm

    Incidentally, there is “evidence” of sorts if you look at the composition of the Fellowship of the Royal Society, for example.

    It is easy to attack this as a purely sociological phenomenon, of course, given the way the FRS chooses new fellows – and I don’t make any great claim that it has a great deal of value – but it is nevertheless instructive to compare the proportion of climatologists amongst the FRS fellowship to the proportion of climatalogists amongst all those scientists receiving money from research councils.

  12. hmmm

    It’s a similar picture if you look at the composition of the National Academy of Sciences in the US, by the way.

    Still, that evidence is fairly weak, I admit. Any evidence is likely to be weak because it is not possible to provide an objective measurement.

  13. hmmm

    Sorry, I forgot. Evidence isn’t valid without a link these days, it seems.

    As an illustrative subsample, here are the new fellows of the Royal Society for 2009. These are scientists who other scientists rate highly.


    I count 1 climate scientist (Professor Shine) amongst the 44 new Commonwealth members. I count at least 5 theoretical physicists – more if you count those working in condensed matter physics etc.

  14. Anthony Zacharzewski

    Scientists with years of training and access to highly advanced modelling software, combined with the resources of hundreds of universities and government research institutions, as well as mind-boggling amounts of data sourced by millions of hours of labour in the harshest and most inhospitable parts of the globe – what do they know?

    I laughed out loud at the line about “the credit crunch shows that computer models aren’t up to much”. I think there might be a bit more to the credit crunch than computer modelling. We could start with misaligned personal incentives, herd instinct and greed.

    What’s more – what does financial modelling have to do with climate modelling, other than that they both use computers? My toaster and my kettle both plug into the same electric socket, but for some reason the toast I make in my kettle always disappoints.

  15. Oxford Kevin

    Are these two of the societies that have put out statements in support of the climate scientists? Or are we talking about meteorologists?

  16. hmmm

    Anthony Zacharzewski, yes, my comment was flippant and simplistic. Apologies. I think you will find, though, that much of the failure of risk management was down to poor understanding of the assumptions, implications, global topology, and numerical stability of models. Of course, there may well have been underlying regulatory and policy failures, but I would venture to suggest that a significant fraction of the practical failure originated this way.

    Don’t put scientists on a pedestal, though, unless they really deserve it. Go ahead and sing effusive songs about Debakey, if you like. Praise Dirac to the skies. Which climate scientist will you put in the same league?

    “Highly advanced modelling software” in practice tends to be MATLAB. It’s pretty good but it is off-the-shelf, and definitely doesn’t take a genius to operate it. Of course, programming supercomputers efficiently is still a fairly rare skill, but the most widespread use tends to be cluster applications, and most scientists these days know at least the rudimentary philosophy of multithreaded code. I doubt climate scientists have a huge demand for packages to deal with arbitrary precision arithmetic, but you can use any number of free libraries to do so. I personally have a preference for BigNum but YMMV. Almost everyone doing numerical work knows how to do Monte Carlo simulations. Most know basic speedup algorithms, though they generally aren’t necessary as surprisingly little science is actually computationally intensive.

    I think you will find the basic techniques used for climate modelling, financial modelling, or any kind of numerical modelling are fairly standard. It is very legitimate to compare them. PDEs don’t care what their purpose is; just whether they are elliptic, hyperbolic or parabolic. A Hessenberg matrix doesn’t care whether it’s being used to price CDOs or to calculate currents.

    Collecting data? Well, it is hard for me to judge experimental scientists, as I am have never been one. Speaking generally, measurement requires patience and dedication rather than innovation and genius though. I am glad there are people willing to do this work in dangerous conditions, though.

    I am categorically NOT saying the climate science models are bad, just idly wondering on a day off from work what they said 20 years ago. I’m sure it was perfectly valid and they spelt out their assumptions very clearly. I could just go ahead and look up the journal articles, but I figure, seeing as this is an evidence-based blog, someone will know the references offhand.

    Oxford Kevin, yes, both the RS and NAS wholeheartedly support research in climate change, and as an issue of important public policy, take an active role in trying to disseminate the science, as you would fully expect them to. I have respect for climate scientists – I have respect for all scientists. My main point was that I just don’t see any true genius working in the field though.

  17. Oxford Kevin

    Do those societies just support climate research or have they come out with statements backing the climate scientists position on AGW?
    Does the Royal Society feel so strongly about this issue that they have put out a guide on climate change controversies?

  18. hmmm

    Oxford Kevin, please stop being so paranoid. I am not a climate change sceptic, in the conventional sense. I just think that “evidence” should mean “evidence”, not things which sound like “evidence”. I support the work of the Royal Society in promoting scientific literacy, and scientific outreach programmes, in all their forms, including the excellent public dissemination work on climate science. I have often done outreach work in my own field, and it is refreshing to do so.

    Are you really saying it is unacceptable to think that physics professors are more intelligent, on average, than climate science professors?

  19. Oxford Kevin

    Economic modelling has for too long been dominated by the theories of the Chicago School of economics which posits that we all behave as rational actors when making financial decisions. When in fact human behaviour has lots of elements of herd like behaviour, we put too much weight on recent data, and discount things that happened long ago. This has not just had impacts in the modelling but also in the stripping of regulations relating to the financial sector which were introduced in the thirties. Making comparisons between economic models and ones based on the physics and chemistry as best as we understand them is not really valid.

  20. Oxford Kevin

    Could you please answer my question in relation to the two societies you mentioned about whether they support the climate scientists position on AGW or not and not give a politicians response as you did?

  21. Oxford Kevin

    Could you also answer the questions relating to the royal society?

  22. Oxford Kevin

    I did a physic degree, including radiation transfer, one of the fundamental subjects for climatologists doing atmospheric modelling. Of my fellow students who were good enough to get into research fields in the first place the ones who went into climatology and astrophysics I wouldn’t have felt were better or worse than the ones who went into solid state physics or theoretical physics.

  23. Oxford Kevin

    I’m just saying that we have no or so little evidence to justify the case either way that the discussion is almost pointless. The reason I started to refer to societies that you mentioned was that competent people who have managed to become fellows of those societies seem to be more than comfortable with the results of the research done by the climatologists to back the research fully.

  24. hmmm

    I don’t understand the source of confusion. Let me try again.

    I believe climate change is a severe threat to our way of life. Our earth is warming; there is overwhelming evidence that the cause is man-made. I have my doubts, personally, as to the extent, and this is where I am most sceptical of the historical approach to modelling.

    I fully support the Royal Society trying to dispel climate change myths and am always glad to support scientists in the promulgation of science.

    That said, I still know of no out and out geniuses currently working in the field of climate science – people whose sheer perspicacity will be remembered in spellbound awe in 200 years time. I know of people in other fields of science who fit that description. You are very welcome to disprove my hypothesis by naming a counterexample, of course.

  25. Oxford Kevin

    Thanks for being clear.

    I completed my Physics degree 20 years ago. At that time climatology was an area where there was fierce competition to get into. Perhaps it was for me and some of my classmates that Hansen had just released his famous paper on climate change that provided the interest in climatology as a career choice.

    And there you have someone who I think will be remembered. His later career like most who work in fields of research that rely on highly complex maths was not up to his early work, and it is clear also that his late career motivation was to get something done about climate change, moving away from purely scientific activities. But his early work modelling of aerosols and then working on some of the earliest global climate models and his publication record I would have thought proved him to be a scientist of global standing.

  26. Joss Garman

    Guido – Odds on 2010 will be the hottest year on record.


    This also continues the trend from this decade. The eight warmest years in the 150 global temperature record are, according to the Hadley Center, in order, 1998, 2005, 2003, 2002, 2004, 2006, and 2007. It’s a fact that this is the hottest decade in recorded history.

    All of this said, NASA’s Gavin Schmidt has explained:

    “The first point to make is that the climate system has enormous amounts of variability on day-to-day, month-to-month, year-to-year and decade-to-decade periods. Much of this variability (once you account for the diurnal cycle and the seasons) is apparently chaotic and unrelated to any external factor – it is the weather.”

    Yes, there is a difference between weather and climate. Shocking isn’t it.

  27. Daniel

    OK, some points on climate science, CO2 and computer modelling.

    The biggest greenhouse gas, by volume, is water vapour. Quite hard to sell it as a poison though, and more importantly it is almost impossible to model (water vapour in the atmosphere is non-uniform – clouds). CO2 however is pretty evenly distributed in the atmosphere, with known measurable concentrations – so its fairly easy to model.

    It is important to note, that to this day, the DIRECT link between CO2 production and rising global temperatures has simply not been proven. There is no definate casual relationship. At best, people have managed to show rising temperatures (and then only just) and rising CO2 levels, but no mechanism of causailty.

    Which, to my mind, is hardly surprising, given C02 is a fairly inert gas, vital to life on earth (its plant food ffs) and is in the atmosphere in tiny amounts (around 350ppm). Its not even a very good “greenhouse” gas – water is much better, and HFCs are 10,000 times more effective.

    Lastly, a couple of my friends work in the climate science industry (and yes, it is an industry. One of them described to me the £300m of funding Wales alone spends on climate research). Whilst both are bright, being Cambridge grads, neither did a related subject for their degree, and both are idealogically motivated. They really believe in climate change. As such, I worry about both the quality and he impartiality of their research.

  28. BenM

    No Daniel, that is not it at all.

    You say that water vapour is a more abundant greenhouse gas than CO2 and you are right. However water vapour is a feedback – as the atmosphere heats, so does its capacity to retain moisture. Besides, most weather systems cycle this water within a few days, the excess being precipitated (and the larger the quantity of water in the atmosphere the heavier and more prolonged the downpours, hence the predictions of more flooding events).

    We know that absorption of infra red radiation is a key property of CO2, so we know that the accumulation of CO2 in the atmosphere is likely to lead to increased absorption of infra red radiation as the sun’s rays bounce back off the earth in an attempt to reach space. We know that this will cause the immediate environment of the atmosphere to warm up, and we can see this happening by tracking CO2 levels in the atmosphere alongside the temperature record (as found in ice cores and other proxy sources of data like tree rings etc).

    There is little doubt that increased levels of CO2 in the atmosphere causes a similar rise in global temperatures. And there are all kinds of feedback mechanisms (the water vapour issue being one of them) which magnifies this effect and makes the issue so dangerous. We have the shrinking of ice caps which at the North Pole exposes more ocean which in turn absorbs more heat which melts more ice and so on. We have the potential exposure of millions of tonnes of more the potent greenhouse gas methane as permafrost melts in arctic latitudes.

    You say that some scientists you know get some funding. Well, whoopee-do! What do you expect researchers to do? Live off rations and set up research just for the fun of it?! There are lots of AGW deniers who receive funding too, and much of that is from elements with a direct interest in muddying the waters and casting doubt on the research and integrity of climate scientists. To me, that is bordering on the immoral. Yet you’re more concerned with your hare-brained pet conspiracy. Bizarre.

  29. Oxford Kevin

    Can Daniel show evidence for the Welsh funding of £300 million?

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