June 03, 2013 | Graham

Another explanation of the temperature plateau?



A new paper, lead authored by Australian Randall Donohue of CSIRO, could provide a new clue as to why global temperatures have stood still for almost a decade and a half.

The paper finds that there was a more or less straight line relationship between the 14% increase in CO2 in the atmosphere between 1982 and 2010 and the increase in foliage of 11% due to the CO2 fertilisation effect.

This ought to surprise no-one, but it does give an insight into negative feedbacks to CO2 induced warming.

Most of the really hot weather that we experience is driven by desert and grasslands. On the east coast of Australia that means that the summer winds that come west over the inland plains can produce temperatures in the 40s, while the easterlies and south-easterlies from the ocean don’t produce anything much over 30.

Now, if the area of desert is shrinking, then the heating effect has to be modified, and the paper does note that woody weeds (aka trees) are tending to invade and supplant the grasslands.

That means more shade, and more uptake of energy to build and maintain trees, leading to less energy being released back into the atmosphere for warming.

And there could be another negative effect on temperature. A paper by Sheil and Murdayarso¬†hypothesises that forests create rain by effecting atmospheric circulation. While I’m not endorsing this claim, if it is true, then greater forestation equals higher rainfall, which also equals lower temperature, and faster vegetation growth.

This is all pretty significant stuff, and it makes you wonder why, when I search Google News using Randall Donohue’s name, not one result was from an Australian media organisation.

Indeed, there seems to be more excitement in Tehran than Canberra.



Posted by Graham at 1:02 pm | Comments (12) |
Filed under: Uncategorized

12 Comments

  1. It’s difficult to understand how would deserts affect so much sea surface temperature. Which has a longer plateau than land temps.

    http://plazamoyua.files.wordpress.com/2013/04/temperatura-global-mar-abril-2013.png

    Comment by plazaeme — June 3, 2013 @ 3:59 pm

  2. In all truth Graham the CSIRO don’t really know themselves. The Sun is the greatest influence by far on climate and H2O is most influential warming gas.

    Good article I enjoyed the content.

    Comment by Ross — June 3, 2013 @ 8:27 pm

  3. Very interesting. Most interesting that it comes apparently with the blessing of the CSIRO. This would have been a definite impossibility just a few years back. Could they be running for cover, before the full force of the stuff hitting the fan catches them?

    It appears that they are preparing to acknowledge that there are natural feed back processes that totally counter any effect from CO2. This I expect they hope will allow them to slip out from doing Julia’s bidding, & perhaps even give some genuine research some air, without admitting they were wrong.

    We do live in interesting times, but perhaps, right now, that is no longer a Chinese curse.

    Comment by Hasbeen — June 4, 2013 @ 10:08 am

  4. If one collects a number of air samples, all around a cubic metre, and measure before and after temps.
    Then one will observe that the removal of the Co2 component, equates to a temperature reduction of just 0.03 degrees C every time.
    Whereas, removing the moisture content equates to a temperature reduction of 30C every time.
    Repeatable science is the very bedrock of good science!
    This means that it is water vapour rather than Co2, that is the real climate change gas!
    Co2 is only implicated, as Graham points out, inasmuch as it acts like a super fertilizer, that encourages woody growth in particular, with evergreen rain forest species the most advantaged, which in turn increase the moisture released into the atmosphere. (The greenhouse effect.)
    Trees evaporate 2.5 times the moisture of open water.
    More trapped heat also equates to increased global convection, and more mixing between upper and lower atmospheric layers.
    Meaning, more tornadoes and extreme weather events, including colder winters, as more of the upper atmosphere mixes downwards.
    Interestingly, the stratosphere above the equator is around seventy below, whereas that above the Antarctic regions is only around 40 below.
    This is principally the product of global convection, with the greater tropical heat, pushing the lower and upper atmosphere’s envelope higher, where the absolute zero of outer space begins to impose a greater effect.
    An equal opposite applies in Arctic climes, hence the temperature variations.
    Alan B. Goulding.

    Comment by Alan B. Goulding — June 4, 2013 @ 12:20 pm

  5. You missed a few things Alan.

    CO2 is displacing water vapor in the upper atmosphere. Haven’t you heard about the reducing humidity up there as CO2 increases.

    Then we all know that higher levels of CO2 reduce a plants requirement for water. Makes them more drought tolerant don’t you know. Thus those trees are going to be expiring less water vapor than they did with less CO2.

    Of course any extra growth will of course be expiring water vapor too, so just where do we end up. Could be more or less expired water, but probably similar to previously.

    Gets very complicated doesn’t it?

    The fact is we know stuff all about the effects of CO2, except that it cools the upper atmosphere. From what we are seeing it is a fair bet that more is merrier, & natural feedback effects will keep things in a reasonable range, as it has through many catastrophes in the past.

    Comment by Hasbeen — June 4, 2013 @ 2:12 pm

  6. Has anybody read the latest scientific papers re the effects of the hole in the ozone layer?

    Comment by keith kennelly — June 4, 2013 @ 4:39 pm

  7. Hasbeen, if my aged memory serves, Co2 is a heavy than air gas and tends to collect in folds and hollows.
    This is why it is sometimes referred to as marsh gas.
    Methane sometimes thought of as marsh gas, is a lighter than air gas, and tends to collect at considerable altitude.
    And no, it’s not complicated at all, but particularly when woody growth replaces grassland.
    Which may well be a natural response by nature as she tries to create a new equilibrium?
    Trees aspirate moisture at rates that reflect the heat they are subject to, just as you and I do, with rainforest species in sufficient numbers, creating their own micro climate and localised rain.
    And given Co2 promotes growth, that very growth, may make even larger demands on available water supplies.
    Bigger trees equate to larger thirsts!
    Some plants may seem to become more drought tolerant, but this may be caused by Co2 promoted, more robust root growth and an ability to tap into soil moisture at deeper levels, that would have been previously unattainable?
    I’m surprised you believe that Co2 cools the upper atmosphere? I would have thought the opposite would be true, given the reduced atmospheric pressure.
    Dry ice, “very cold” solid Co2, is made by massively increasing pressure, and a thing called fractional distillation.
    Which as fact, seems to fly in the face of your assertion, of it cooling the upper atmosphere?
    It’s possible it could cool in the upper atmosphere, along with everything else?
    Alan B. Goulding

    Comment by Alan B. Goulding — June 4, 2013 @ 5:43 pm

  8. Alan B Goulding is a good example of the deception used by these green ideologues. In one instant he gives us an example of how rainforest species create their own micro climates causing localised rain.

    Here is the deceptive part. Alan ” And given that CO2 promotes growth, that very growth, may make even greater demands on available water supplies.” Alan is trying to imply that CO2 causes another evil ie plant growth which taxes our water supplies. Plants Alan cannot make dangerous demands on water supplies because they stop growing with less water and CO2 does not harm the environment by creating more plant growth. The over riding factor is the availability of water and not the availability of CO2 in plant growth.

    This statement also contradicts your observation that plants moderate climate by keeping moisture in the air rather than being trapped in underground storage such as artesian basins. Without the extra plant growth we’d have more Sahara Deserts. Surely extra plant growth within the parameters of available water supply is a good thing for soils, climate, animal populations and humans.

    Comment by Ross — June 6, 2013 @ 6:33 pm

  9. My understanding is that absorption of CO2 by the oceans, along with increased soot particles from China and India, have moderated the temperature.

    However, the increase in water vapor has also led to increases in extreme weather events:
    http://www.extremeweatherheroes.org/science-of-extreme-weather/global-evidence.aspx

    Comment by Ronda Jambe — June 8, 2013 @ 2:49 pm

  10. Ross, you completely misrepresent me and my views!
    If you had sufficient intelligence to actually understand the science, you would have understood, (reread comment no 4) that moisture rather than Co2 is the real heat trapping gas in the atmosphere!
    And rainforests do create their own micro climate, hence the name, rain forests.
    That information is just factual, rather than the spin/misrepresentation you seem to excel in?
    The only Ideologue deliberately misrepresenting the facts here, and my views, to support a purely POLITICAL view point here, seems to be only you Ross?
    You have a nice day now.
    Alan.

    Comment by Alan B. Goulding — June 11, 2013 @ 11:10 am

  11. Ronda you’ve got to stop reading those propaganda sheets, just like some other bad habits, they can make you go blind. Well at least to the truth.

    Alan now you have agreed that water vapor is the main green house gas, [in your terminology], you will have to agree that anything that reduces the water vapor in the atmosphere will reduce temperature.

    The fact that humidity is diminishing, as CO2 increases in the upper atmosphere does indicate that cO2 is a cooling agent.

    Please no garbage about CO2 being heavy & only near the ground. Balloons have long shown the fact of mixing.

    Comment by Hasbeen — June 11, 2013 @ 11:56 am

  12. Hasbeen; I did not say there was no mixing. Point to any post where I made that assertion! [Arguably you are just putting your words in my mouth, then arguing against that same assumption, or quite gross misrepresentation! Well, it’s your time!] :-(
    Just that as a heavier gas, Co2 tends to find its way down to folds and hollows.
    I have not conceded anything, just reported repeatable science, as I have done on many other occasions, for over two decades!
    You like balloons then?
    Perhaps if you filled a balloon with Co2, and then left it to find its own level in a closed room.
    You can prove for yourself, that it tends to float downward and hug the floor!
    This tends to happen in the atmosphere as well, unless affected by other factors, like say thermals and wind that has to force its way over mountains.
    If you can agree that our oceans seem to be undergoing some temperature increases, in places as much as a reported 2C, then you will also have to agree, that will invariably lead to more evaporation and increasing humidity, rather than less?
    If you step outside your door and study the sky, you might, from time to time, note thin wispy streaky clouds in the stratosphere, sometimes referred to as mares tails.
    Not only a good indicator of future rain, but increased upper atmosphere moisture.
    >The fact that humidity is diminishing,< is not a fact at all, just your apparent misreading of information?
    Or put another way, a terminological inexactitude?
    Cheers, Alan.

    Comment by Alan B. Goulding — June 12, 2013 @ 6:51 pm

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