Models are not Reality
Mars Melt Hints at Solar, Not Human, Cause for Warming, Scientist Says, Kate Ravilious, National Geographic News, February 28, 2007 (h/t Orrin Judd)
Simultaneous warming on Earth and Mars suggests that our planet's recent climate changes have a natural—and not a human-induced—cause, according to one scientist's controversial theory.
Earth is currently experiencing rapid warming, which the vast majority of climate scientists says is due to humans pumping huge amounts of greenhouse gases into the atmosphere.
Mars, too, appears to be enjoying more mild and balmy temperatures. [...] In 2005 data from NASA's Mars Global Surveyor and Odyssey missions revealed that the carbon dioxide "ice caps" near Mars's south pole had been diminishing for three summers in a row. [See for instance, Mars Ski Report: Snow is Hard, Dense and Disappearing]
Habibullo Abdussamatov, head of the St. Petersburg's Pulkovo Astronomical Observatory in Russia, says the Mars data is evidence that the current global warming on Earth is being caused by changes in the sun. [...] "The long-term increase in solar irradiance is heating both Earth and Mars," he said. [...] Abdussamatov believes that changes in the sun's heat output can account for almost all the climate changes we see on both planets.
Mars and Earth, for instance, have experienced periodic ice ages throughout their histories. [...] By studying fluctuations in the warmth of the sun, Abdussamatov believes he can see a pattern that fits with the ups and downs in climate we see on Earth and Mars.
Abdussamatov's work, however, has not been well received by other climate scientists. [...] "His views are completely at odds with the mainstream scientific opinion," said Colin Wilson, a planetary physicist at England's Oxford University.
"And they contradict the extensive evidence presented in the most recent IPCC [Intergovernmental Panel on Climate Change] report." (Related: "Global Warming 'Very Likely' Caused by Humans, World Climate Experts Say" [February 2, 2007].) [...] Amato Evan, a climate scientist at the University of Wisconsin, Madison, added that "the idea just isn't supported by the theory or by the observations."
All planets experience a few wobbles as they make their journey around the sun. [...] These fluctuations change the tilt of Earth's axis and its distance from the sun and are thought to be responsible for the waxing and waning of ice ages on Earth. [...] Mars and Earth wobble in different ways, and most scientists think it is pure coincidence that both planets are between ice ages right now.
So let us examine the theory and observations as Mr. Evan suggests. The majority of heat for the Earth's surface undoubtedly comes from the Sun, with a small portion produced geothermally. It has long been suspected that a decline in Solar radiation coupled with increased volcanic activity was responsible for the Little Ice Age. While many studies claim to find no variation in Solar output, a recent study, Sun's Output Increasing in Possible Trend Fueling Global Warming, reanalyzing satellite data indicates that Solar output has been increasing for the last 20-30 years. The IPCC report, whose primary evidence is the Mann Hockey-stick graph, has been questioned by statisticians, since the methods used produce the same Hockey-stick shape when fed random data, and there are discrepancies between the proxy temperature data sets used and historic temperature data. Nor can the IPCC computer climate models accurately reproduce the last 10 or 20 year temperature records. As for humans producing "huge" amounts of greenhouse gases: "NOAA research estimates that 97% of atmospheric CO2 created each year is from natural sources and approximately 3% is from human activities." Nor are present levels abnormally high: "Although contemporary CO2 concentrations were exceeded during earlier geological epochs, present carbon dioxide levels are likely higher now than at any time during the past 20 million years and at the same time lower than at any time in history if we look at time scales longer than 50 million years." (source), and see also this graph ("Both measurements and models show considerable uncertainty and variation; however, all point to carbon dioxide levels in the past that have been signifcantly higher than they are at present.")
Finally, "mainstream scientific opinion" is never the sole criterion of truth - there are too many counter-examples in history for this argument to be more than merely suggestive. What is certain is that many climatologists are heavily invested in promoting research and grant money, which is easier if there is an imminent crisis. And arguing that the same phenomenon occurring on two planets is pure coincidence is surely a rather lame one.