“Everything we know is only some kind of approximation, because we know that we do not know all the laws as yet. Therefore, things must be learned only to be unlearned again or, more likely, to be corrected.” Richard Feynman Lectures in Physics .
Both whales and elephants have larger brains than Homo sapiens. They have larger memories and faster processing capabilities . Our accomplishments are not due to our intellectual superiority to these animals with whom we’ve co-evolved but to our thumbs. We can write things down and store information, first on cave walls and clay tablets and more recently on flash drives, so that we have access to the sum of human knowledge and not just the information we carry in our own brains. Whales and elephants are individually limited to what each animal can memorize and pass on verbally. Homo neanderthalensis also may have had a larger brain. Our superiority over Neanderthals may be due to our capacity for complex language, a lucky evolutionary happenstance. It is not to superior individual intellectual gifts to which we owe our success as a species but to our ability to accumulate, communicate and share information and scientific knowledge.
The sum of human knowledge, documented by our science, includes the periodic table of elements, the human genome, the catalogue of celestial objects, the geologic time scale, the theory of gravity, electromagnetic fields, quantum electrodynamics, evolution, how to build a car, how to cook, agricultural sciences and the taxonomy of life and much more. Not everybody knows all of this stuff but it is all written down and we can pass it on. Occasionally, some humans have set themselves up as judges of what knowledge is proper and have destroyed libraries such as the library of Alexandria in 391 AD and the Iraq National Library in Baghdad in 2003. Throughout history scientists have been attacked, imprisoned and beheaded, the fate of Antoine Lavoisier, discoverer of oxygen.
Global warming denier attacks on climate scientists are therefore attacks on all science and really attacks on our humanity. We’ve observed the Heartland Institute’s Diane Bast, and the pundit Alexander Cockburn presume to judge scientists they disagree with  and I cannot think of anybody less competent than these two unless it is Virginia State Attorney General Ken Cuccinelli.
Scientists Make Mistakes
Scientists do make mistakes and often publish results which are later found to be in error, or simply incomplete. Often they make assumptions which are later shown to be wrong. That’s fine. Science progresses by such fits and starts. I give two relevant examples below where scientists published papers which contain major mistakes.
We’ve seen previously  that denier Richard Lindzen  published a mistaken hypothesis regarding a possible negative feedback mechanism which he suggested might mitigate global warming. Even the technical team for the now-defunct industry funded misinformation group Global Climate Coalition concluded :
“Lindzen’s hypothesis that any warming would create more rain which would cool and dry the upper troposphere did offer a mechanism for balancing the effect of increased greenhouse gases. However, the data supporting this hypothesis is weak, and even Lindzen has stopped presenting it as an alternative to the conventional model of climate change.”
No Attorney General subpoenaed Lindzen or his university and in fact he did nothing wrong other than make a mistake.
In another example, deniers Roy Spencer and John Christy wrote a paper in 1990  which attempted to reconcile weather balloon measurements of atmospheric temperature with satellite-based measurements. Satellite measurements began in 1978 but weather balloon data had existed for decades. In their paper the authors postulate that though the troposphere (the lowest layer of the atmosphere) had warmed, it had not warmed as fast as the surface temperature. Their results showed a warming trend of 0.09°C per decade, below the surface temperature trend of 0.17°C per decade.
There has never been a scientific paper written that suggested that the troposphere had not warmed at all by the way. The importance of the paper to denier arguments was that climate models predict that the troposphere would warm faster than the Earth’s surface when CO2 was increased. In other words, if the results from Spencer and Christy held, then either the models were wrong or the cause of the observed Earth’s surface temperature increase might not be atmospheric CO2.
In November 2005, Carl Mears and Frank Wentz  at Remote Sensing Systems (RSS)  performed an independent analysis of the satellite data. In the process, they found an algebraic error in the Spencer and Christy analysis  which Christy and Spencer later acknowledged  which adjusted their estimate of the atmospheric warming upwards to 0.12°C per decade. Furthermore, Mears and Wentz performed their own data analysis and showed a trend of 0.19°C per decade, in line with the climate model predictions.
Since this was such an important foundation stone in the denier argument, the issue was adjudicated by the U. S. Climate Change Science Program in a paper  co-authored by John Christy, which concludes:
“Previously reported discrepancies between the amount of warming near the surface and higher in the atmosphere have been used to challenge the reliability of climate models and the reality of human induced global warming. This significant discrepancy no longer exists because errors in the satellite and radiosonde data have been identified and corrected. While these data are consistent with the results from climate models at the global scale, discrepancies in the tropics remain to be resolved.
“This difference between models and observations may arise from errors that are common to all models, from errors in the observational data sets, or from a combination of these factors. The second explanation is favored, but the issue is still open.” 
Though deniers still cite Spencer and Christy, we note that the discrepancy they reported no longer exists and the most likely explanation for differences between climate models and observations were in fact errors in the observational data sets made by Spencer and Christy. We see that an important argument for global warming denial was in fact wrong. Nobody accused Christy and Spencer of lying or falsifying their data to agree with their ideology. Christy and Spencer made a few mistakes. Those mistakes were corrected when other scientists attempted to duplicate their results further strengthening the scientific support for anthropogenic global warming theory. Since the Mears paper, scientists from Yale have shown by making more accurate measurements that even the discrepancy between climate models and measured temperature in the tropics referred to by the NAS study no longer exists .
The Case against Michael Mann
The IPCC AR-3 published in 2001 , contained a curve produced by Michael Mann showing the temperature anomaly during the last 1000 years as measured by proxies. This is his famous hockey stick curve. Had Mann’s results contained mistakes then Mann would have been no guiltier than deniers Lindzen, Spencer and Christy of anything more than having been wrong. But Mann’s results are correct and have been validated many times.
Mann’s curve shows a relatively constant temperature, which solar scientists such as Usoskin  have shown to be consistent with solar radiation and other natural forcing functions, until the latter part of the twentieth century, when the Earth surface temperature rose dramatically, as a result of human emissions of greenhouse gases, resembling a hockey stick shape.
The study by Usoskin et al.  finds that “the solar series shows a ‘Hockey Stick’ shape” except for the blade confirming the Mann Hockey Stick. As an aside we note that two popular denier arguments actually contradict each other, one that the Hockey Stick has been debunked and the other that the warming is due to solar energy and not greenhouse gas emissions. Recently Mann  further strengthened the proxy evidence and extends the reconstruction back nearly 2000 years (see figure 1).
Figure 1 shows the latest Holocene climate reconstructions from several proxies . The Medieval Warm Period, roughly centered about 1000 A. D., and the Little Ice Age, roughly centered about 1700 A. D., are visible. These events are generally attributed to a variation of solar irradiation of about +/- 0.2 W/m2. Note that this figure includes the results from Moberg  which as we’ve seen  deniers cite in support of the denial view. From this figure we observe that the recent warming is unprecedented in both amount and rate of change. Note that it is the rate of change which is particularly frightening.
I’ve never understood why deniers are so committed to trying to debunk Michael Mann’s hockey stick. Denier’s insistence on exaggerating the cooling during the little ice age or the warming during the medieval warm period actually hurts their position because it would mean that the climate is even more sensitive to forcings than assumed in the IPCC report. The solar forcing during the little ice age was about 0.2 W/m2 [17, 18, 19] while the total current forcing is about 1.6 W/m2 or about eight times stronger . You can see the problem, if natural variability is indeed stronger than expected and acts as an amplifier.
Scientists at the National Center for Atmospheric Research published a paper  in 2009 which further confirms Michael Mann’s hockey stick temperature record. Using independent scientific techniques they’ve reconstructed the temperature record for the arctic. Their results shown in figure 2 reinforce the consensus view.
Mann has been exonerated by the Pennsylvania State University . His science has been validated by one study after another including an examination by the National Academy of Sciences  and even by papers cited by deniers. The obvious conclusion is that Michael Mann performed important, relevant and quite accurate science that has stood the test of time. His results have been repeatedly duplicated by other researchers using different methods. His research has helped humans understand our predicament and improve our chances of survival. The case against Michael Mann has been fabricated by unscrupulous and ignorant people and doesn’t exist.
The Case against Attorney General Cuccinelli
On April 23 Virginia State Attorney General Ken Cuccinelli issued a subpoena against the University of Virginia requesting all the emails, correspondence, computer codes and other documents of Michael Mann. The subpoena does not contain any evidence of any violation of any law according to the journal Nature.
Humans have for the first time faced an existential crisis by assembling our best and most knowledgeable thinkers on the subject when the UN and the World Meteorological Association in cooperation with all governments and industry established the Intergovernmental Panel on Climate Change to examine the potential threat of anthropogenic global warming. Every single major science organization in the world has endorsed their findings and every government, including the United States, has accepted their conclusions. Most people are too busy with their lives to dedicate the large amounts of time necessary to try to understand this complex issue. All folks who accept the conclusions are behaving entirely rationally. The problem of anthropogenic global warming is so overwhelming that it cannot be solved unless humans cooperate. This means we have to have some form of regulation. Industry knows this and that is why they fund the global warming disinformation campaign.
We all know that deregulation of industry leads to disaster such as President Reagan’s savings and loan fiasco, Senator Gramm’s recent recession caused by his 1999 deregulation of the financial sector (Goldman Sachs et al) act, Massey Coal’s Upper Big Branch Mine explosion and of course British Petroleum’s disastrous Gulf oil explosion. In fact democracy and free markets do not work without good independent government regulation. We’ve seen this. We know this.
The scientific evidence supporting anthropogenic global warming is so compelling and so thorough, so entirely consistent with all human knowledge that the only recourse left to the fossil fuel industry is to attack certain climate scientists. Michael Mann has performed high quality science and his results are not convenient for the fossil fuel industry. By attacking him, presumably they hope to scare off other scientists from telling the truth. We think of this kind of thing happening in the Soviet Union or Communist China. In fact Climate Scientist Ken Caldeira slammed anti-scientific witchhunts asking: “Are American politicians following in the footsteps of Stalin?”  The U-VA faculty Senate averred that Cuccinelli actions threaten “our ability to generate the knowledge upon which informed public policy relies.”
The energy and natural resources industry was Cuccinelli’s largest donor sector  in his run for Attorney General contributing $47,465. So perhaps it is not surprising that Cuccinelli is spending taxpayer dollars on a witch hunt to persecute climate scientist Michael Mann of Penn State without evidence and without cause. Cuccinelli has no basis for a law suit and any judge reading the NAS paper will throw him out of court on his derrière. Cuccinelli must know this. He is not stupid. Thus Cuccinelli’s intention may be harassment. This he achieves by his subpoena.
On May 12, 2010, the science journal Nature  scathingly attacked Cuccinelli’s subpoena as baseless pointing out that he gave no evidence of any wrong doing on the part of Mann.
On May 7, 2010, 255 scientist including 11 Nobel laureates published a letter in the journal Science stating that “We are deeply disturbed by the recent escalation of political assaults on scientists in general and on climate scientists in particular.” 
I do not know if Cuccinelli is just another corrupt politician doing the biding of those who paid for his election. But he would make a great petty bureaucrat in Stalinist Russia.
In other News
In other climate news, Science just published yet another report on species extinction due to global warming  consistent with ‘alarmist’ warnings and NASA and NOAA both report that we’ve just had the hottest April on record following the hottest January-February-March on record . If 2010 turns out to be the hottest year on record which is looking likely, wait until next year when you will be hearing Cuccinelli and other deniers argue that global warming stopped in 2010. Also Jeff Masters of Weather Underground reports  that the Sea Surface Temperatures (SSTs) in the Atlantic’s Main Development Region for hurricanes had their warmest April on record being an eye-opening 1.46°C above average. This anomaly, according to Masters, foretells another record hurricane season and bears watching.
 Richard Feynman Lectures in Physics, The definitive Edition, Volume I, Addison Wesley, 2006.
 John D. Barrow, New Theories of Everything, Oxford University Press, 2007.
 Lindzen, R. S., “Some Coolness Concerning Global Warming”, American Meteorological Society, Vol. 71, No. 3, March 1990.
 Global Climate Coalition see http://en.wikipedia.org/wiki/Global_Climate_Coalition and http://www.sourcewatch.org/index.php?title=Global_Climate_Coalition
 Spencer, R. W., and Christy, J. R., 1990 Precise monitoring of global temperature trends from satellites, Science 247: 1558-1562.
 Mears, CA, FJ Wentz, 2005, The effect of drifting measurement time on satellite-derived lower tropospheric temperature, Science, 309, 1548-1551
 Wigley, T. M. L., V. Ramaswamy, J.R. Christy, J.R. Lanzante, C.A. Mears, B.D. Santer, C.K. Folland, 2006 “Temperature Trends in the Lower Atmosphere – Understanding and Reconciling Differences executive summary”, US Government, April, 2006.
 Allen et al. Warming maximum in the tropical upper troposphere deduced from thermal winds. Nature Geoscience, 25 May 2008 DOI: 10.1038/ngeo208. See also http://www.sciencedaily.com/releases/2008/05/080530144943.htm
 Intergovernmental Panel on Climate Change, 2001, http://www.ipcc.ch/
 Usoskin, I. G., Schussler, M., Solanki, S. K., and Mursula, K. 2004 Solaractivity over the last 1150 years: does it correlate with climate?, Proc. 13th Cool Stars Workshop, Hamburg, 5-9 July 2004.
 Mann, M., Zhang, Z., Hughes, M., Bradley, R., Miller, S., Rutherford, S., and Ni, F., 2008, , “Proxy-based reconstructions of hemispheric and global surface temperature variations over the past two millennia”, Proceedings of the National Academy of Sciences
 Anders Moberg, Dmitry M. Sonechkin, Karin Holmgren, Nina M. Datsenko and Wibjörn Karlén, “Highly variable Northern Hemisphere temperatures reconstructed from low- and high-resolution proxy data,” (Nature 433, 613-617, February 2005)
 Wang, Y.-M., J. L. Lean, J. L., and Sheeley, N. R. Jr , Modeling the sun’s magnetic field and irradiance since 1713, The Astrophysical Journal, 625:522–538, May 20, 2005
 Krivova, N. A., Balmaceda, L., and Solanki, S. K., Reconstruction of solar total irradiance since 1700 from the surface magnetic flux, Astronomy and Astrophysics, Volume 467, Number 1, May III 2007, 335 – 346.
 Shindell, D. T. , Schmidt, G. A., Mann, M. E., Rind, D., and Waple, A., 2001, Solar Forcing of Regional Climate Change During the Maunder Minimum, Science, vol 294 7, December, 2001.
 Trenberth, K. E., 2009: An imperative for adapting to climate change: Tracking Earth’s global energy. Current Opinion in Environmental Sustainability, 1, 19-27. DOI 10.1016/j.cosust.2009.06.001.
 Darrell S. Kaufman, David P. Schneider, Nicholas P. McKay, Caspar M. Ammann, Raymond S. Bradley, Keith R. Briffa, Gifford H. Miller, Bette L. Otto-Bliesner, Jonathan T. Overpeck, Bo M. Vinther, and Arctic Lakes 2k Project Members, “Recent Warming Reverses Long-Term Arctic Cooling”, Science 4 September 2009 325: 1236-1239 [DOI: 10.1126/science.1173983]
 National Academy of Sciences, 2005, SURFACE TEMPERATURE RECONSTRUCTIONS FOR THE LAST 2,000 YEARS Committee on Surface Temperature Reconstructions for the Last 2,000 Years Board on Atmospheric Sciences and Climate Division on Earth and Life Studies www.nap.edu
 B. Sinervo et al, “Erosion of Lizard Diversity by Climate Change and Altered Thermal Niches” Science 14 May 2010: Vol. 328. no. 5980, pp. 894 – 899 DOI: 10.1126/science.1184695, http://www.sciencemag.org/cgi/content/abstract/328/5980/894