The main argument of climate alarmism supported by IPCC is that ice core records show a close correlation between the concentration of CO2 in the atmosphere and global temperature over the last four glacial-interglacial cycles. This is taken as evidence that CO2 is an important greenhouse gas, which introduced in climate models predicts that doubling of preindustrial CO2 could cause global warming of up to 6 degrees Celcius. On this basis IPCC recommends control of CO2 emissions, to be negotiated at the UN Climate Change Conference in Copenhagen in December as a continuation of the Kyoto Protocol.
However, the data shows that CO2 lags temperature with about 800 years, which is compatible with the fact that a warm ocean releases more CO2, just as a warm bottle of coke.
The evidence thus suggests that it is the temperature that influences the CO2 concentration in the atmosphere, and not the other way around. The fundamental argument of climate alarmism supplied by IPCC thus seems to lack rationale...or maybe the dependence is not as simple like that...see the discussion below...anyway the fundamental scientific problem is this: What is the climate sensitivity or the effect on global temperature of carbondioxide emission?
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But this isn't mysterious. The mainstream view is that the ice-age cycle is driven by the Milankovitch cycles and amplified by the CO2 which comes out of the ocean and other carbon sinks. The difference in insolation created by the Milankovitch shifts is not enough to directly create the multi-degree shift in temperature from glacial to interglacial.
SvaraRaderaÅh nej, Claes, inte detta gamla missförstånd igen om koldioxiden och uppvärmningen, och att kausaliteten bara verkar i en riktning. En kort förklaring finns här, eller i min Folkvett-uppsats från förra året om du skulle föredra den.
SvaraRaderaJag är förvånad och uppriktigt sagt lite upprörd över hur illa påläst du är och ändå tycker dig vara i stånd att värdera och till och med döma ut en hel vetenskap. Att gemene man skulle förstå hur mycket som krävs för ett sådant arbete är kanske för mycket begärt (och därför får vi acceptera en del egendomligheter i bloggosfären och på tidningarnas insändarsidor) men att du - en professorskollega! - gör samma misstag finner jag anmärkningsvärt.
Ett rimligt minimikrav för den som har ambitionen att vederlägga en hel vetenskap är att denne känner till vad vetenskapen faktiskt hävdar och vilka argumenten är. Om du vill fortsätta ditt korståg mot klimatvetenskapen föreslår jag att du först inhämtar dessa kunskaper. I ditt fall skulle jag föreslå att du börjar någorlunda från grunden med de böcker jag rekommenderar här.
I didn't see Mitchell's comment until I had sent mine. His explanation is right on target.
SvaraRaderaSure, there is always something to learn from your opponents arguments.
SvaraRaderaBut the fact is that climate alarmism is based on predictions of climate models with input that CO2 is a greenhouse gas with positive feed-back. The question is if these predictions have anything to do with reality. What do you think Olle and Mitchell? What is your expertize on computational climate modeling? Or is it consensus again?
Olle H,
SvaraRaderaDu påstår fräckt och felaktigt att klimatalarmismen är vetenskap när Du skriver "Om du vill fortsätta ditt korståg mot klimatvetenskapen..."
Claes, I'm sorry, but these are the real questions: Why is Earth five degrees warmer in an interglacial period? Why did the Antarctic ice sheet form? Why is the world getting warmer now? You don't have to be a climate modeller to understand the argument. Climate models are about details, not principles.
SvaraRaderaWith simplistic arguments you can come to any conclusion about a complex system like the global climate.
SvaraRaderaClaes, I don't think that is true - with simple arguments you can only really come to one conclusion about the global climate system. It is only when people use misdirection and distorted arguments that you come to the false conclusion.
SvaraRaderaGetting back to CO2 feedbacks, it has been obvious for a long time that such feedbacks are critical to the climate swings that the earth has experienced in the past - the small changes in solar input may have triggered the ice age cycle but are far too small to have caused 5+ degree swings. The same for earlier warming intervals (Eemian etc). So by simplistic argument we know that the climate is extremely sensitive to perturbations in the forcing, with amplification by way of such feedbacks. The models simplistically provide a way to quantify the feedback effects.
What we are doing today is providing a forcing input (because of the direct CO2 insulation effect) that is in itself comparable or larger than the forcing that led to ice age type changes in climate. So the simplistic logical conclusion is that comparable feedback effects will take place, driving the climate into a significantly warmer state [over the next few centuries or so].
The one big difference between our present forcing and previous [solar] forcings is that we are largely in control of this one - we can choose to continue [increasing] the CO2 effect, or can choose to turn that effect down by reducing CO2 production and by removing CO2 from the atmosphere.
As Mitchell says, the models provide the details. And they provide estimates quantifying these effects both direct and including future feedbacks. They also allow us to plan policies to ameliorate the forcing that are based on a scientific understanding of the problem rather than simplistic guesstimates.
I agree that simplistic arguments may not capture the true dynamics and feedbacks, but that also applies to current climate models and their postulated feedbacks which seem simplistic.
SvaraRadera