CO2 and temperature don’t correlate


The whole theory of man-made climate change depends on the idea that CO2 drives climate.  And if you look at just the last hundred years, say, there does seem to be a loose correlation.  Not a very precise correlation: atmospheric CO2 goes up steadily (though with an annual wobble reflecting the seasons – CO2absorbed in spring and summer), while mean global temperatures are much messier.  But fair enough – you could argue that other random or cyclical factors may be superimposed on the inexorable rise associated with CO2.

If you take the last 600,000 years, as Al Gore did in his film “An Inconvenient Truth”, there is a more conspicuous correlation.  But the really inconvenient truth for Al Gore is that a finer-scale analysis of the data shows that the temperature curve leads the COcurve, suggesting that temperature drives CO2 rather thanvice versa.  There is also a credible mechanism to account for this phenomenon.  As the oceans warm, CO2previously dissolved in them is released into the atmosphere, but is re-absorbed when they cool.

The longer-term geo-historical perspective illustrated in the graph covers the last 600 million years – virtually the whole period of multi-cellular life on earth.  And throughout that period we see a long-term decline in atmospheric CO2, from a maximum of 7000 parts per million (ppm) down to around 250 in the early 20thcentury.  Note that 250 ppm is an all-time record low.  Indeed it is a dangerous low.  Biologists tell us that if the level fell much below 200 ppm, photosynthesis and plant growth would cease, and all animal life would die in consequence.  A very low CO2 level would be an existential crisis for life on earth.  It perhaps illustrates the absurdity of the warmist paranoia about the current level of 400 ppm to reflect that in geo-historical terms it remains very low indeed – and that the level has been as much as seventeen times higher.

Also worth noting that at those very high levels of CO2, there was no excessive temperature rise, no tipping point, no runaway global warming.  Indeed there is almost no correlation between CO2 and temperature.  There are sharp changes in both graphs, but no correspondence between the two.

The sharp changes in the temperature graph can be interpreted as ice ages caused by astronomical cycles and factors, even though these effects are not very well understood.  Also worth noting that there seem to be two “natural” levels for mean global temperatures – either around 22oC, or down to 12oC.  While most of the last 600 million years has been at the higher level, the world now is unusually cool (we are of course in an Ice Age, though fortunately for us we are enjoying one of the Interglacials that occur every 120,000 years or so – but may end soon).

So far as CO2 goes, we can see a long-term decline over the period, interrupted by a low-CO2 anomaly in the carboniferous.  The long-term decline over the period can be interpreted as the effect of calcifying species, and especially hard-shelled sea creatures, which have progressively sequestered CO2 as calcium carbonate – chalk – ending up in geological strata.  The Carboniferous dip is the result of the evolution of trees and woody plants.  When these first evolved, there were no organisms that could mediate the decomposition of wood, so very large amounts of CO2 were sequestered in layers of dead wood which became coal.  But eventually fungi and other organisms evolved which could live off, and decompose, dead wood, which is why the CO2 level recovered around 280 million years ago and resumed its previous downward trajectory.

This long decline was only reversed when the industrial revolution started to return some of the CO2sequestered in coal and oil back into the atmosphere.  Far from creating an exceptional and dangerous situation, we are merely taking a tiny step to redress a long-term decline and move atmospheric CO2 levels slightly towards the geo-historical norm.


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35 Responses to CO2 and temperature don’t correlate

  1. ian wragg says:

    As you say Roger, below 200 ppm it is likely that animal life would start to decline and it is difficult to see where the figure of 400ppm makes any sense.
    The temperature graph indicates that we could be in for another mini ice age so perhaps we should be encouraging the burning of fossil fuels.
    As it is a religion you are dealing with, I think you are wasting your time. Nothing will sway the zealots particularly the BBC from their mission to have us all living in caves.

  2. Jane Davies says:

    Never mind any of that Roger, you are missing the real threat. We should all be worrying about being overrun with cute little kittens, never mind Planet of the Apes cats could take over the earth and it’s all down to man made global warming, you have been warned!

  3. Ex-expat Colin says:

    No worry…the jet stream is fast reversing. I used it from JFK to LHR once before and lost out on a free beer.

    Its all about evidence. Trouble is, all if it is way too short term, but needs to be fixed up, and up. Anyway, I want to know why Greenpish did not obstruct the Shetland Gas drilling…and the SNP?

    Paul Homewood has got a good piece on wood pellets.:(and much other stuff)

  4. brent lyon says:

    Their is truth in what you say, but moving to a lower carbon world also helps in other ways such as improving air quality. It would be best overall to make a gradual shift to producing lower carbon energy particularly as the lead times are so long.

    • Roger Helmer MEP says:

      Sorry Brent, but I think you may be conflating two separate issues. CO2 is not pollution — it’s merely a trace gas essential to life on earth. It’s true that combustion of fossil fuels also results in the emission of real pollutants, SOx, NOx and particulates, and we are quite right to take action to minimise those pollutants. Modern coal-fired plants are hugely cleaner than those decades ago. But the greens are too keen to attack CO2 as “a pollutant” when it is no such thing.

    • Brin Jenkins says:

      I will go with the cleaner burn produces less CO2 but thats not the criteria used in our taxation of cars. My old Merc at 55 MPG paid £225 road tax for some political reason when it was a very clean burn. With such muddled thinking is the any wonder over the polution testing muck up with VW? They met the test standards as laid down.

  5. catweazle666 says:

    brent lyon says:
    February 10, 2016 at 7:40 pm
    “Their is truth in what you say, but moving to a lower carbon world also helps in other ways such as improving air quality”

    Since when has a few ppm of extra CO2 damaged air quality? CO2 IS NOT a pollutant.

    Certainly plants don’t think it is:

    Increased levels of carbon dioxide (CO2) have helped boost green foliage across the world’s arid regions over the past 30 years through a process called CO2 fertilisation, according to CSIRO research.

    In findings based on satellite observations, CSIRO, in collaboration with the Australian National University (ANU), found that this CO2 fertilisation correlated with an 11 per cent increase in foliage cover from 1982-2010 across parts of the arid areas studied in Australia, North America, the Middle East and Africa, according to CSIRO research scientist, Dr Randall Donohue.

    Nor do coccolithophores:

    Coccolithophores — tiny calcifying plants that are part of the foundation of the marine food web — have been increasing in relative abundance in the North Atlantic over the last 45 years, as carbon input into ocean waters has increased. Their relative abundance has increased 10 times, or by an order of magnitude, during this sampling period. This finding was diametrically opposed to what scientists had expected since coccolithophores make their plates out of calcium carbonate, which is becoming more difficult as the ocean becomes more acidic and pH is reduced.

    The latter paper casts considerable doubt on much of the alarmism over “ocean acidification” too, incidentally.

    So all in all, it seems that at the present levels of increase of atmospheric CO2, it is a practically unmitigated benefit.

    • Brin Jenkins says:

      This ties in with my experience in Sicily where Mnt Etna is in a constantly active state. The increase in CO2 has raised the fertility far above places close by without the volcanic blessing.

      Perhaps if we had 5-600 CO2 parts per million the climate might improve a little but we would all eat better with less artificial fertiliser leaving the oil in the ground!

  6. Nivek Ecyoj says:

    cheap energy = prosperity so keep burning the carbon, our children deserve it.

    • Brin Jenkins says:

      Umm, a bit too simple! If we had cleaner burns without as much residue it would be better conservation of resources. I’m all for that without the semi religious fervor of the greenies..

  7. Ex-expat Colin says:

    Info… not on the repetitive and stale BBC news yesterday or today:

    4 parties share a platform to make the case to leave the EU. John Redwoods blog”

    “Some readers of this site will be pleased to know that Conservative, Labour and Democratic Unionist party MPs joined with UKIP MEPs to make common cause this afternoon for leave. BBC cameras and various journalists were present. The conference was entitled “The Good life after Brexit”. The common platform included Liam Fox, David Davis, Bernard Jenkin, Nigel Farage, Graham Stringer, Ian Paisley and myself.

    I am grateful to David Campbell Bannerman MEP for organising the event and giving us such a good introduction to the case for leaving.”

  8. tapestory says:

    The climate is controlled by CO2 to this extent. The ice establishes and is hard to shift once it does, during ice ages. The ice reflects 95% of the warmth of the sun back out to space. The earth dries as a result of the ice capturing all the H2O and plants die off deprived of CO2. The resulting dust begins to storm for thousands of years depositing increasing layers of material on top of the ice. This material then starts to recapture the warmth of the sun. The ice starts to melt and an interglacial period results. The interglacial period ends when the earth tilts the northern hemisphere further away from the sun during the earth’s 25,000 year cycle which Stonehenge was designed to measure, built 14,000 years ago by the same team that designed and built the pyramids at Giza, and when CO2 falls below 100 ppm.

    The climatic history of earth going back tens of thousands of years can be detected from multiple ice samples taken from all around the globe.

    In the interglacial period, accessible H2O and CO2 reestablish and plants regrow until the amount of CO2 starts to decline once more. Before that happens, the dust storms end, and the earth is warm once more. For a lot more and better explained, go to Ralph Ellis’ website and read his papers on climate.

  9. Chris Newton says:

    I never hear any reference to the amount of water produced from burning fuel. Water vapour is the biggest green house gas eg a clear night is cold and a cloudy night is warm. This is because clouds are keeping the heat in and not allowing it to reflect back into space. For every litre of petrol burnt a litre of water is produce ( a litre of water makes 1.6 cubic metres of steam) You cannot get rid of water it just evaporates and condenses as rain hence, more clouds. Water is also produced from burning gas just look at the steam coming out of you central heating flue on a cold morning. The same amount is coming out when it’s a bit warmer (you just can’t see it) It must be staggering the amount coming from a gas fired power station. Don’t be confused by the stem coming from cooling towers that’s ok as its coming from water already here.
    Heat from engines, an internal combustion engine is at best 20% efficient so the other 80% of the heat produced is blown out from the radiator. The amount of heat and water being added to the natural cycle of these two processes must have a huge effect on the global climate.

    • ian wragg says:

      The water from combustion is not produced, it is vapour in the air which is compressed and then cooled causing it to condense out.
      If you check our power station chimney on cold damp days you get a large steam plume from the chimney, on warm dry (low humidity ) days the chimney is clear. We have to keep the flue gas higher than the dew point to avoid corrosion.

      • Derek says:

        It is not correct to say the water from combustion is not produced. As all chemistry students will know, coal, gas and oil all contain hydrocarbons. The carbon combines with oxygen to produce CO2 and the hydrogen produces H2O. However this water vapour is insignificant when compared with the water vapour already present in the atmosphere via evaporation from the vast oceans.

    • Brin Jenkins says:

      I dispute the greenhouse effect in the open atmosphere? The effect of the CO2 molecule is over estimated considerably and gravity possibly has a similar effect.

  10. Chris Newton says:

    Ian, that’s not true. The water is manufactured during the combustion process eg natural gas is CH4 (4 parts hydrogen and 4 parts carbon) to burn the fuel we must add oxygen. When the hydrogen and oxygen combine they make water. In the combustion process the water is turned to steam (robbing the fuel of some of its gross calorific value) the steam produced is emitted in the flue gasses. The same occurs with most fossilised fuels including petrol and diesel. NB The water coming out of your exhaust pipe on a very cold day. You only see it when its cold because the steam produced condenses in the cold exhaust pipe. When the engine and the exhaust system heats up the water and steam disappear. They’re still there but you can’t see them steam is an invisible gas you only see it when it has condensed.
    Your point about dew point corrosion is correct that’s why we have to keep the exhaust temp above the ‘acid’ dew point which is 58 degrees C for natural gas ( the main reason for this is that nitrogen being roughly 75% of air mixes during the combustion process and the resultant ‘water’ is in fact nitric acid)
    Even on warm humid days the steam is still coming from your chimney its just by the time it condenses it’s so far away from the chimney and dispersed it’s no longer visible.

  11. Jim Hunt says:

    Have you read this by any chance Roger?

    “What exactly is the greenhouse effect? And what does it look like if we view it from a new angle? Of course, we know the answer, and Raymond Pierrehumbert has written an excellent paper about it”

    • catweazle666 says:

      Ah, realclimate…Home of arch-Mannipulator Gavin Schmitt and his rapid reaction ‘Crusher Crew’.

      Personally, I prefer the ‘Beano’ myself.

      More scientific credibility, you see.

    • Jim Hunt says:

      Thank you Roger’s webmaster. That didn’t take long did it? It was posted at “February 12, 2016 at 2:49 pm” but my comment’s only just appeared.

      Re: catweazle666 says: February 13, 2016 at 7:16 pm:

      Do you have anything to offer apart from ad homs? Something with “scientific credibility” on the topic of “CO2 and temperature” for example?

      • catweazle666 says:

        I would have more success converting the Pope to Satanism than having a sensible scientific debate with a fully indoctrinated evangelist like you who sources all his “science” from crackpot alarmist blogs, sunshine. If you live that long you’ll still be wittering about Catastrophic Anthropogenic Global Warming and that we’re all doomed to boil or fry when the glaciers return and roll over your bridge.

        I’ve come across you before remember, and you’re a fine one to accuse anyone of ad homs.

      • Jim Hunt says:

        Roger assures me that “I’ll debate any time Jim. But not in 140 characters”.

        I’m here to debate with him, not listen to an incessant stream of ad homs with zero “scientific credibility” from you, or anybody else for that matter.

        Is there any chance Roger’s webmaster can call this house to some sort of order? Alternatively we could always pop on over to my place?

  12. Jim Hunt says:

    Roger is still conspicuous by his absence from the “debate”, but at least it’s quieter in here this morning!

    Let’s see if I can get the ball rolling with this quote from the academic journal paper I linked to, which is authored by Rasmus Benestad, not Gavin Schmidt:

    It is usually an advantage knowing why your explanation makes sense when you try to make an impressions on others. The same can be said for explaining climate change to the general public and informing them about how the greenhouse effect (GHE) is altered by the burning of fossil
    fuels. Despite a strong consensus on climate change within the climate research community, the efforts to explain climate change to the society so far can be summed up as having had limited success.

    • Roger Helmer MEP says:

      And your point is? You think your explanation makes sense when the IPCC itself suggests an extraordinarily wide range of estimates for CO2 climate sensitivity? And when some scientists suggest that the figure may even be negative, as a result of negative feed-backs (e.g. cloud cover and albedo)? I am amused to hear that I am “absent from the debate” when I am, in fact, engaged in it on a daily basis.

      • Jim Hunt says:

        My apologies Roger – Whilst you were replying here I was typing in a comment on your latest article. That comment is still “awaiting moderation”. Feel free to ignore item 0!

        I haven’t made a point and/or explanation yet, beyond enquiring whether you had read an interesting (to me at least) new paper on “explaining climate change to the general public”. See item 2 in my new comment, once it emerges from purgatory.

        I did of course mean “absent from any debate with yours truly in these hallowed halls, since 8:46 AM yesterday.”

    • catweazle666 says:

      “Despite a strong consensus on climate change within the climate research community, the efforts to explain climate change to the society so far can be summed up as having had limited success.”

      You could say that, Jimbo. And guess what – it’s getting worse for you lot every day.

      It seems the public at large is nowhere near as credulous as you believe it should be.

      Out in the real world, the CAGW hoax is losing credibility fast.

      Public support for a strong global deal on climate change has declined, according to a poll carried out in 20 countries.

      Only four now have majorities in favour of their governments setting ambitious targets at a global conference in Paris.

      In a similar poll before the Copenhagen meeting in 2009, eight countries had majorities favouring tough action.

      The poll has been provided to the BBC by research group GlobeScan.

      Just under half of all those surveyed viewed climate change as a “very serious” problem this year, compared with 63% in 2009.

      The findings will make sober reading for global political leaders, who will gather in Paris next week for the start of the United Nations climate conference, known as COP21.

      The 2015 United Nations ‘My World’ global survey of causes for concern currently covering 9,719,726 respondents shows ‘action on climate change’ flat last, 16th of 16 categories.

      You see, you can fool some of the people some of the time, and some of the people all of the time, but you can’t fool all of the people all of the time.

      Oh, and don’t come the old soldier about only climate “scientists” (which you aren’t, not evan a scientist at all as far as I can tell) are qualified to judge on such matters, that’s like saying only a chef is qualified to comment on the quality of a meal.

      You see, you don’t need to be a cowboy to recognise the smell of bullshit when it’s been stuffed under your nose for three decades, with no evidence whatsoever that is cherry pie or whatever.

      Crying “WOLF!” can only work for so long, and as not a single one of the catastrophic predictions of the Warmist religion over the last 3 decades has actually come to pass – in fact in the majority of cases such as hurricane landfall frequency, tornado energy and polar ice disappearance to name but three of many they have been diametrically wrong – their credibility is rapidly approaching zero. And don’t mention the ‘pause’…

      The real problem is that these scammers and the credulous bedwetters that unquestioningly support them are destroying the credibility of real science – and not just in the field of climate either, and just as in the fable, when a real wolf does come – and it will, sooner or later, nobody will believe them.

      And then we will really be in trouble, and the likes of you and your crackpot alarmist bloggers will be responsible for it.

      Think on that (but I know you won’t).

  13. Pingback: Climate deniers? Science deniers? | Roger Helmer MEP

  14. Jim Hunt says:

    The sun has risen once again over Soggy South-West England. I have still received no reply to my enquiry on Twitter, so I’ll try restate it here where there is plenty of space for a reply containing far more than 140 characters!

    Please can you provide a link to some peer reviewed research that supports your “97% of scientists believe in AGW” assertion on Twitter?

    Thanks in anticipation.

  15. Phil says:

    You would only expect CO2 and temperature to correlate if Solar output remained constant over the graphed period, which it hasn’t (It was lower in the distant past – see

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