Tag Archives: Gish Gallop

Matt Ridley needs to take some advice from Matt Ridley

Matt Ridley is a techno-optimist of the Lomborgian mold, with all of the cherry-picking and source misrepresentation that goes with it apparently. He gave a speech to the Royal College of Physicians of Edinburgh [corrected - see below] that has “skeptics” falling all over themselves in delight.

What groundbreaking evidence does Ridley marshal in defense of his rejection of mainstream science?

I was curious. Ridley ostensibly is a cut above the average denizen of WUWT. He was trained as a zoologist before taking up science writing. He has articles frequently published in the mainstream press, as the delicious-in-hindsight tweet by Andy Revkin reflects. He’s widely acclaimed for popularizing science concepts for mainstream reading audiences. So whatever Ridley had must be good, I thought. His arguments would reflect the best of the “skeptics’” best.

It turned out I was wrong. Or perhaps, I was right, and Ridley was bringing the best of the “skeptics’” best. Either way, it was an enormous disappointment. Ridley’s speech turned out to be a textbook Gish Gallop, full of false claims, logical fallacies, and trivially true but irrelevant “facts”. It was, as I put it at Keith Kloor’s blog, “skeptic” bingo.

  • Sea level rise is small and is decelerating!
  • Methane isn’t increasing!
  • Hockey Stick!
  • Etc.

I don’t think I will do a point by point rebuttal to every claim in Ridely’s speech at this time (maybe later, for sport, time permitting). But suffice it to say that while Ridley is being lauded by the denialosphere now, he’s actually done them a tremendous disservice. With this speech, he’s fully exposing himself as a crank, and has thus reduced the ever-dwindling list of “credible skeptics” one further.

And in case anyone is curious, while the year-to-year variability is significant,  on climate-relevant timescales, sea level rise is indeed accelerating (Church and White 2011; Rahmstorf and Vermeer 2011).

But more to the point, absent emissions stabilization, sea level rise is going to increase, reaching 1m or more by end of century (Vermeer and Rahmstorf 2009).

Failure to stabilize emissions will almost assuredly result in the eventual collapse of the Greenland and Antarctic ice sheets, committing the world to multimeter sea level rise that will be for all practical purposes irreversible. Many of Ridley’s claims similarly depend on falsely equivocating between concern over future climate changes absent emissions stabilization (and their relative irreversibility over human timescales) and what is happening at present. This couldn’t be more misleading.

As you might imagine, given the way this is going, Ridley’s claim that methane isn’t increasing is also false. Methane levels today are much higher than they’ve been over at least the past 800,000 years and continue to increase (Loulergue et al., 2008; NOAA AGGI).

The “hockey stick” nonsense has been done to death. And “skeptics” like Ridley inevitably fail to mention the main points: the “hockey stick” has basically nothing to do with either the attribution of recent warming to humans or the seriousness of future warming; the ostensible statistical problems in the original Mann et al. paper were overstated by its critics, and the actual problems it did have don’t tremendously affect its results (Huybers 2005; Wahl and Amman 2007); moreover, independent Northern Hemisphere reconstructions (including “skeptics’” own) show more or less the same results as Mann et al.’s recent work- the warming during the instrumental record exceeds peak Medieval temperatures (Ljunqvist 2010; Loehle and McCulloch 2008; Mann et al., 2008; Moberg, et al., 2005).

People like Ridley spend an awful lot of time listening to “skeptic” bloggers like Jo Nova and Bishop Hill, but seem to have no grasp of basic Earth systems science. And it shows. There is a total lack of coherence in Ridley’s claims. Ridley wants us to know that the climate changed rapidly in the past- but yet we’re also supposed to believe that climate sensitivity is very small. He also flubs basic concepts- equilibrium sensitivity is not the same thing as transient sensitivity (i.e. how much we will warm in response to a given increase in radiative forcing is larger than how much warming we’ll experience in the near term due to things like the thermal inertia of the ocean).

Perhaps Ridley can follow his own advice and “unlearn” the lies, fallacies, and nonsense he’s being cheered for regurgitating. Though let’s just say I’m a little skeptical of the prospect.


  • Church, J.A., and N.J. White (2011): Sea-Level Rise from the Late 19th to the Early 21st Century. Surveys In Geophysics, 32, 4-5, 585-602, doi:10.1007/s10712-011-9119-1.
  • Huybers, P. (2005): Comment on “Hockey sticks, principal components, and spurious significance” by S. McIntyre and R. McKitrick. Geophysical Research Letters, 32, L20705, doi:10.1029/2005GL023395.Ljungqvist, F.C. (2010): A new reconstruction of temperature variability in the extra-tropical northern hemisphere during the last two millennia. Geografiska Annaler: Series A, 92, 3, 339-351, doi:10.1111/j.1468-0459.2010.00399.x.
  • Loehle, C. and J.H. McCulloch (2008): Correction to: A 2000-Year Global Temperature Reconstruction Based on Non-Tree Ring Proxies. Energy + Environment, 19, 1, 93-100.
  • Loulergue, L., et al. (2008): Orbital and millennial-scale features of atmospheric CH4 over the past 800,000 years. Nature, 453, 383-386, doi:10.1038/nature06950.
  • Mann, M.E., et al. (2008): Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia. Proceedings of the National Academy of Sciences (USA), 105, 36, 13252-13257, doi:10.1073/pnas.0805721105.
  • Moberg, A., et al. (2005): Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data. Nature, 433, 613-617, doi:10.1038/nature03265.
  • NOAA AGGI: The NOAA Annual Greenhouse Gas Index. URL: http://www.esrl.noaa.gov/gmd/aggi/
  • Rahmstorf, S., and M. Vermmer (2011): Discussion of: “Houston, J.R. and Dean, R.G., 2011. Sea-Level Acceleration Based on U.S. Tide Gauges and Extensions of Previous Global-Gauge Analyses”. Journal of Coastal Research, 27, 4, 784–787, doi:10.2112/JCOASTRES-D-11-00082.1.
  • Vermeer, M., and S. Rahmstorf (2009): Global sea level linked to global temperature. Proceedings of the National Academy of Sciences (USA), 106, 51, 21527-21532, doi:10.1073/pnas.0907765106.
  • Wahl, E.R., and C.M. Ammann (2007): Robustness of the Mann, Bradley, Hughes reconstruction of surface temperatures: Examination of criticisms based on the nature and processing of proxy climate evidence. Climatic Change, 85, 33-69, doi:10.1007/s10584-006-9105-7.