The Resilient Earth
Thursday, Oct 15th, 2009
According to State of the Climate in 2008, a special supplement to the August, 2009, issue of the Bulletin of the American Meteorological Society, greenhouse warming has been stopped in its tracks for the past 10 years. The HadCRUT3 temperature record shows the world warmed by only 0.07°C (±0.07°C) from 1999-2008. The UN’s Intergovernmental Panel on Climate Change, who have led the global warming disaster circus for the past two decades, had predicted 0.20°C. Just a temporary setback claim the true believers, global warming will be back with a vengeance. Add a mad scientist’s cackling laugh and you have a story fit for a comic book villain.
Climate researcher Jeff Knight and eight colleagues at the UK’s Met Office Hadley Centre first announced the news that global warming had gone on hiatus. When corrected for the natural temperature effects of El Niño and La Niña events, the decade’s temperature trend is a perfectly flat 0.00°C. Yet climate scientist Gavin Schmidt of NASA’s Goddard Institute for Space Studies (GISS) says “In the end, global warming will prevail!” Ah, the sound of denial in the face of abject failure. The story is written in the figure below taken from “What Happened to Global Warming? Scientists Say Just Wait a Bit” by Richard A. Kerr in the October 9 issue of Science: Earth’s temperature hasn’t warmed since 1999.
Adapted from J. Knight et al., Bull. Amer. Meteor. Soc., August 2009.
As reported in the Science article: “the Hadley Centre group took the next step, using climate modeling to try to quantify how unusual a 10-year warming pause might be. In 10 modeling runs of 21st century climate totaling 700 years worth of simulation, long-term warming proceeded about as expected: 2.0°C by the end of the century. But along the way in the 700 years of simulation, about 17 separate 10-year intervals had temperature trends resembling that of the past decade—that is, more or less flat.” Trouble is, when the cooling decades occur is not accurately predicted, they appear more or less randomly. In other words, we can make our models nearly as unpredictable as the real climate!
Climate modelers are currently in a mad scramble to rescue their tattered playthings from the drubbing they have taken for not predicting the current cooling trend. Judith L. Lean, a solar physicist at the US Naval Research Laboratory, and David H. Rind, a climate modeler at GISS, have published a paper entitled “How will Earth’s surface temperature change in future decades?” in the August 15 Geophysical Research Letters. In it they decomposed recent observed surface temperatures into components associated with ENSO, volcanic and solar activity, and anthropogenic influences, in an attempt to anticipate global and regional changes during the next two decades. Unlike the Hadley Centre’s model-based analysis, their assessment attributes an increased amount of climate variability to change in solar activity. Considering recent developments this is a step in the right direction.
Acknowledging that decadal climate forecasts are difficult to make with general circulation climate models due to their many uncertainties, the authors cite two different modeling studies that arrived at vastly different conclusions. By including overturning of the ocean’s meridional circulation (MOC) in a numerical model and using observed distributions of ocean heat content for initialization, Smith et al., (see “Improved Surface Temperature Prediction for the Coming Decade from a Global Climate Model”) forecast rapid warming after 2008, with “at least half of the 5 years after 2009… predicted to exceed (1998) the warmest year currently on record.” The other model, from Keenlyside et al., (see “Advancing decadal-scale climate prediction in the North Atlantic sector”) also attempts to account for the MOC yet forecasts the opposite result: “that global surface temperature may not increase over the next decade, as natural climate variations in the North Atlantic and tropical Pacific temporarily offset the projected anthropogenic warming.” Lean and Rind describe how their approach differs from these two projections:
An alternative approach to numerical model simulations for assessing recent climate change and forecasting future change in the next two decades is direct analysis of surface temperature observations. By isolating and quantifying the specific changes arising from individual natural and anthropogenic influences, the causes of past change are identified, thereby rendering forecasts for future decades possible, assuming plausible future scenarios expected for each influence. We use this empirical approach to develop global and regional surface temperature scenarios for the next two decades.
Even so their results look suspiciously similar to all the other recent, hastily revised forecasts from climate change traditionalists. As can be seen from the figure below, nothing has changed with regard to the assumed linear increase in temperature attributed to CO2. Despite recent work by Meehl et al. (see “Atmospheric Solar Heat Amplifier Discovered”) that insolation may have three times the impact on climate compared with previous predictions the old, dogmatic 2°C per century is still there.
Observed and modeled monthly mean global temperatures. From Lean and Rind 2009.
This derives from a fundamental assumption made by the modelers: “The major assumption associated with our forecasts is that ‘past is prologue’; climate will continue to respond in the future to the same factors that have influenced it in the recent past and the response will continue to be linear over the next several decades.” The thing is, that same argument can be made on other timescales—for instance, on a century long time scale a linear temperature prediction would call for only a 0.7°C increase by 2100. Here is their bottom-line conclusion: “According to our prediction, which is anchored in the reality of observed changes in the recent past, warming from 2009 to 2014 will exceed that due to anthropogenic influences alone but global temperatures will increase only slightly from 2014 to 2019, and some regions may even cool.”
A survey of the many new predictions being generated by the world’s climate research groups produces at least one set of prognostications for every imaginable scenario. The whole enterprise is reminiscent of Medieval mystics claiming to predict the future while spouting gibberish. Palm readers and fortune tellers stand as good a chance as any in this game. Lean and Rind are calling for global warming to reassert itself next year, run hot for five years and then go quiescent for another five—add that to the list of predictions. We will see how their prediction fares, because the future outcome will be decided by the ultimate arbiter in science, nature itself.
Be safe, enjoy the interglacial and stay skeptical.
This article was posted: Thursday, October 15, 2009 at 4:14 am