October 20, 2008 | Graham

Another global warming tipping point

I just came across Joanne Nova and her The Skeptics Handbook. Joanne appears to be eminently qualified as a scientist, and a science communicator, having even occassionally stood-in for Dr Karl on ABC radio. She can’t be dismissed as some sort of an outsider, and unlike many of the skeptics she’s not a superannuated professor, but someone mid-career. Taking this position is a considerable career risk.
The Handbook is a good read as it condenses the argument down to its basics. One of the problems on this issue is the degree of complexity that can easily intrude into it. Faced with complexity most people throw up their hands and just do what everyone else is doing, which on this issue plays into bad policy making.
Joanne’s analysis asks the major “so what” questions, and the answers are readily comprehensible by anyone. Her takeout message is “…There is only one question that matters: ‘will adding more CO2 to the atmosphere make the world much warmer now?”
And on the question of tipping points.

Atmospheric carbon is at higher levels than any time in the last 650,000 years. But go back 500 million years, and carbon levels were not just 10-20% higher, they were ten to twenty times higher. The Earth has thoroughly tested the runaway greenhouse effect, and n o t h i n g happened. Indeed the earth slipped into an ice age while CO2 was far higher than today’s levels. Whatever warming effect super-concentrated-CO2 has, it’s no match for the other climactic forces out there. Further, it doesn’t matter if it’s man-made-CO2 or ocean-made-CO2. They are the same molecule.

But more significantly, Joanne was a believer until 2007, and she lists a number of others who have also changed their minds recently. It seems that while policy is heading in one direction, reality is heading in the other, which should eventually, one way or another, give us another tipping point.

Posted by Graham at 10:38 pm | Comments (3) |
Filed under: Environment


  1. It takes 5 kms to change the course of a super taker under full power.It will probably take 5 yrs for the momentum of the global warming zealots to dissipate.The financial crisis will slow it considerably.
    Just like the Y2K bug it will become a distant memory and another piece of human stupidity will be relegated to our dustbin of denial.
    I do think however that our climate is being affected by man’s actions and we need to do a lot more research.CO2 it seems is more an effect rather than a cause.
    We had the weapons of mass destruction which did not exist,terrorists which were mainly financial terrorists in our own midst,the Y2K bug,the threat of communism in the 70’S,even the threat of an ice age due to the burning of fossil fuels.
    Take it all with a grain of salt.The sky will be always falling so long as someone can see a way of gaining power and making an easy quid.

    Comment by Arjay — October 21, 2008 @ 6:09 pm

  2. “The Earth has thoroughly tested the runaway greenhouse effect, and n o t h i n g happened.” That statement is somewhat esoteric.
    I’m drawn to Paleontologist, Dewey Mclean’s hypothesis on the Deccan Traps Volcanism – the Greenhouse Dinosaur Extinction Theory. McLean alludes to the Deccan Traps volcanism involvement in the K-T extinctions which caused huge and long-duration volcanic events releasing prodigious amounts of the greenhouse gas, carbon dioxide, onto earth’s surface.
    He hypothesised that embryos are unable to reach maturity due to carbon warming hence the extinction of the dinosaurs.
    Mammalians were at the time, few and small creatures where their size enhanced their survival. McLean also claims that current extinctions are occurring due to warming.
    Several paleontologists claim greenhouse gases and CO2 were high during all previous five extinctions except one.
    Since humans now release 150 times more CO2 than volcanoes, let’s hope we will not again see the extent of volcanism similar to the Deccan Traps.
    Should that occur, I would say that accommodation on Earth would be most difficult and the planet’s tenants may not bear any resemblance to homo-sapiens.
    It’s intriguing to note that authors, such as the above (and other skeptics) fail to acknowledge or debate the previous mass extinctions which correlated with high carbon emissions – particularly now that we are in the midst of the Sixth Extinction.

    Comment by Stuart — October 26, 2008 @ 8:32 am

  3. Stuart during those extinctions CO2 levels were 1200% higher than now.We have only added 30% more Co2 to the atmosphere and still our climate presently cools.This may be the lull before the storm but even you true believers should get things in perspective.
    We may well decend into an ice age,since in our distant past,we had one with co2 levels many times that of the present.
    Most of the present extinctions are being caused by man both directly and indirectly affecting the environment.It has nothing to do with co2.You like many others mis-interpret cause and effect scenarios to enhance you argument.The ice core data reveal that CO2 is an effect rather than a cause.

    Comment by Arjay — October 26, 2008 @ 5:13 pm

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