A Few Things Ill Considered

(image info and credits)

Fake skeptics of anthropogenic global warming love to set up the straw man that mainstream climate science believes that CO2 is the one and only driver of climate change.  They can then use it in many different attacks, such as gee whiz isn’t it stupid that they haven’t even thought of the sun’s influence.  This is of course patently false as even the most cursory survey of actual scientific content will quickly reveal.  This straw man is also an implicit part of the argument that the “16 year pause” in global warming proves that CO2 is not a climate driver.  If CO2 has risen and temperature has not, then the theory of AGW has failed, they say.  Well, this would only be true if CO2 were believed to be the only possible driver of the surface temperature record.  (For this post I am ignoring the two facts that, one, 16 years is not enough to unambiguously show a trend and two, there actually is an upward trend).

Well, some recent research out of the University of Colorado, Boulder has found that despite the lack of any major eruptions, like that of Pinatubo in 1991, there has in fact been a significant increase in volcanic aerosols in the stratosphere over the last decade.  This increase is large enough that its cooling effect could mask as much as 25% of the greenhouse warming we would expect to see if CO2 really were on its own as a climatic influence.

Between 2000 and 2010, the average atmospheric concentration of carbon dioxide — a planet-warming greenhouse gas — rose more than 5%, from about 370 parts per million to nearly 390 parts per million. If that uptick were the only factor driving climate change during the period, global average temperature would have risen about 0.2°C, says Ryan Neely III, an atmospheric scientist at the University of Colorado, Boulder. But a surge in the concentration of light-scattering particles in the stratosphere countered as much as 25% of that potential temperature increase, he notes.

Further modeling indicates that the Asian Brown Cloud, unpleasant and influential as it may be regionally, does not explain the global data being recorded by satellite observation.

Now, by using a computer model that includes processes due to global atmospheric circulation and atmospheric chemistry, Neely and his colleagues show that the human contribution of aerosols to the stratosphere was minimal between 2000 and 2010. In one set of simulations, the researchers estimated the effects of all known volcanic eruptions, including the quantity of aerosols produced and the heights to which they wafted, on the month-to-month variations in particulate concentrations.

The pattern of stratospheric particulate variations during the past decade “shows the fingerprint of volcanoes, with the right episodes showing up at the right time,” says William Randel, an atmospheric scientist at the National Center for Atmospheric Research in Boulder.

This is an excellent illustration of why what the IPCC publishes are not called predictions, nor can they fairly be treated as such.  They are projections of what would happen given assumed trajectories of key climatic forcing agents.  When those agents, be they insolation, CO2 concentrations, stratospheric aerosol concentrations, ozone or albedo changes, do not actually change the way it was assumed in a climate model run, this is not the fault of the model.

So in summary, we have now yet another reason to dismiss the suggestions that recent surface temperature trends require the scrapping of the last 150 years of research and we must abandon the idea that humans are changing the global climate. We are changing the global climate, and the temporary amelioration of our disastrous warming influence by other natural factors is not likely to last long.

Comments

  1. #1 mandas
    March 8, 2013

    Coby

    Of course, you know that deniers are also going to say that this research proves that volcanoes emit more CO2 than humans. In 3, 2, 1, ……………

  2. #2 freddy
    March 9, 2013

    mandas, can you cite articles which quantify CO2 emissions from submarine volcanoes in the pacific ocean?

  3. #3 Wow
    March 9, 2013

    Yes, so can you if you only google.

    The US geological survey group look at that sort of thing for the USA.

    All volcanoes add up to between less-than-1% and 3% of human production.

  4. #4 Dan L
    March 10, 2013

    This last paragraph is a mess:

    “So in summary, we have now yet another reason to dismiss the notion that recent surface temperature trends require the scraping of the last 150 years of research we must abandon the notion that humans are changing the global climate.”

    Scrapping, not scraping, I think, embedded in an accidental run-on sentence which is also missing a negation.

    Feel free to delete my comment if you fix the sentence.

  5. #5 coby
    March 11, 2013

    That was a mess, is hopefully better now…

  6. […] 2013/03/08: AFTIC: Volcanos may be countering greenhouse warming […]

  7. #7 freddy
    March 18, 2013

    Of course do volcanos counteract any atmospheric warming. The degree of the cooling effect is completely unknown since science has no sufficient values about submarine volcano eruptions. This deficiency in knowledge and GCMS parametrization is insufficiently known to the people outside the climate science circles, i.e. among politicians, media people, ordinary people like wow, jan, mandas, marco, etc. anf many other back seats in the audience without knowledge about what’s going in science.

  8. #8 Wow
    March 18, 2013

    “Of course do volcanos counteract any atmospheric warming”

    Really? So ANY amount of atmospheric warming is removed by volcanoes? But that would mean the world would drop to -33C after an eruption.

    Please explain why this doesn’t happen.

  9. #9 Marco
    March 19, 2013

    And how does freddykaitroll propose submarine volcanoes “counteract” atmospheric warming?

    This “ordinary [person] not only knows about submarine volcanoes, he even knows that their effect on global climate, based on the assessment of volcanologists, is unlikely to be anything more than noise. Their effect on the trend is likely even less, as there is no evidence whatsoever of a trend in activity in the submarine volcanoes that are being monitored.

    Freddykaitroll is once again showing off his ignorance.

  10. #10 freddy
    March 19, 2013

    coby, people ask me something and you preven me from answering. At least you could inform the blog participants that you censor me. Could you please com back to civility and abstain from German nazi police-like actions against me and civilized manners. Be a man and try to avoid the impression that you are one of the most primitive censors on the internet. I have already been banned several times from alarmist blogs, but every time the blog master had announced it. Not too long ago you proudly stated here that you would not censor any person. So what is your problem??
    [coby: I have never said I would not censor anybody, and besides you have not been censored, I am just slowing you down. That makes your trolling a little less enjoyable for you, then that is probably the point. I do however really dislike sock puppets, take your handle either Kai or Freddy and stick with it.]

  11. #11 Wow
    March 19, 2013

    “And how does freddykaitroll propose submarine volcanoes “counteract” atmospheric warming?”

    And without heating the oceans to be noticed, either.

  12. #12 Wow
    March 19, 2013

    “At least you could inform the blog participants that you censor me.”

    Censorship is government stopping you speaking, right?

    And you can still type what you want elsewhere, can’t you? So you’re not being censored at all, you’re just not being given a platform by someone else to speak.

    Get your own.

  13. #13 freddy
    March 19, 2013

    coby, thank you, fair enough. I slow down, you are right.

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