New Study: Climate Alarmism Takes One Helluva Beating

sensitivityNic Lewis reports on the publication of a very important paper in Journal of Climate. Bjorn Stevens has created a new estimate of the cooling effects of pollution (“aerosols”) on the climate. Readers will no doubt recall that to the extent that aerosol cooling is small the warming effect of carbon dioxide must also be small so that the two cancel out to match the observed temperature record. Only if aerosol cooling is large can the effect of carbon dioxide be large. –Andrew Montford, Bishop Hill, 19 March 2015

Remember folks, the IPCC’s official upper bound is 4.5°C, but Stevens’ results suggest that ECS can’t be above 1.8°C. Jim Hansen, Bob Ward, Kevin Trenberth, Michael Mann and Gavin Schmidt, your climate alarmism just took one helluva beating. –Andrew Montford, Bishop Hill, 19 March 2015

Since [the publication of the IPCC’s] AR5, various papers concerning aerosol forcing have been published, without really narrowing down the uncertainty range. Aerosol forcing is extremely complex, and estimating it is very difficult. In this context, what is IMO a compelling new paper by Bjorn Stevens estimating aerosol forcing using multiple physically-based, observationally-constrained approaches is a game changer. -Nic Lewis, Climate Audit, 19 March 2015

Comments (2)

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    You mean it wasn’t just natural climate factors that tweak temperatures after all ?

    Simply curious but does anyone know if scientists have agreed to a list of factors that influence climate and then ranked or to put a weight to those factors compared to each factor .

    Over simplifying of course but sunspot activity ,the extent of ice ,changes in ocean currents ,volcanic activity ,cloud cover, forest coverage etc are always in a state of flux yet combined drive climate overwhelmingly as they always have .

    Humans contribution of CO2 compared to naturally generated CO2 is miniscule however when considering and including natural variables influence how is it that human generated CO2 has any measurable effect at all ?

    Sunspot activity for example is volatile but measurable.Are we able to determine what the effect on the earth’s temperature is caused by sunspot activity?.

    If sunspot activity is the most influential variable (no idea if it is ) and it was given a weight of say 30% (no idea if it should be ) how can we communicate the range of temperature change attributed to fluctuations in sunspot activity but also in the context of other major natural variables .

    There is a huge lack of understanding by non-scientists generally about the relative influence that human generated CO2 could have compared to natural factors.

    The scary global warming promoters exploit that lack of knowledge and context because they can .

    Most people would agree that everything humans do has some influence or effect but whether it is even measurable is another question .

    Relative to the influence of natural variability the impact of human generated CO2 will not drive the worlds temperature in any meaningful way . How best to illustrate that is probably worth a revisit .

    I’d be grateful to be directed to
    that information in hope that it can be presented in layman’s terms if not already so .

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      [i]There is a huge lack of understanding by [s]non-[/s]scientists generally about the relative influence that human generated CO2 could have compared to natural factors. [/i]

      Fixed it for you.

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