Mars Is Warming, NASA Scientists Report
The planet Mars is undergoing significant global warming, new data from the National Aeronautics and Space Administration (NASA) show, lending support to many climatologists' claims that the Earth's modest warming during the past century is due primarily to a recent upsurge in solar energy.
Martian Ice Shrinking Dramatically
According to a September 20 NASA news release, "for three Mars summers in a row, deposits of frozen carbon dioxide near Mars' south pole have shrunk from the previous year's size, suggesting a climate change in progress." Because a Martian year is approximately twice as long as an Earth year, the shrinking of the Martian polar ice cap has been ongoing for at least six Earth years.
The shrinking is substantial. According to Michael Malin, principal investigator for the Mars Orbiter Camera, the polar ice cap is shrinking at "a prodigious rate."
"The images, documenting changes from 1999 to 2005, suggest the climate on Mars is presently warmer, and perhaps getting warmer still, than it was several decades or centuries ago," reported Yahoo News on September 20.
Solar Link Possible
Scientists are not sure whether the Martian warming is entirely due to Mars-specific forces or may be the result of other forces, such as increasing solar output, which would explain much of the recent asserted warming of the Earth as well.
Sallie Baliunas, chair of the Science Advisory Board at the George C. Marshall Institute, said, "Pluto, like Mars, is also undergoing warming." However, Baliunas speculated it is "likely not the sun but long-term processes on Mars and Pluto" causing the warming. However, until more information is gathered, Baliunas said, it is difficult to know for sure.
Pat Michaels, past president of the American Association of State Climatologists and senior fellow at the Cato Institute, similarly expressed a desire for more information about the Martian climate. "What is the internal dynamic that is warming Mars?" asked Michaels. "Given the fact that there are not a lot of anthropogenic greenhouse gas emissions on Mars, and given the fact that new research indicates that 10 to 30 percent estimated conservatively of Earth's recent warming is due to increased solar output, the Martian warming may support that new research."
Models May Be Wrong
The new research mentioned by Michaels is the October 2 release of findings by Duke University scientists that "at least 10 to 30 percent of global warming measured during the past two decades may be due to increased solar output rather than factors such as increased heat-absorbing carbon dioxin gas released by various human activities."
"The problem is that Earth's atmosphere is not in thermodynamic equilibrium with the sun," Duke associate research scientist Nicola Scafetta explained in a Duke University news release. Moreover, "the longer the time period [that the Earth's atmosphere is not in thermodynamic equilibrium] the stronger the effect will be on the atmosphere, because it takes time to adapt."
Examining a 22-year interval of reliable solar data going back to 1980, the Duke scientists were able to filter out shorter-range effects that can influence surface temperatures but are not related to global warming. Such effects include volcanic eruptions and ocean current changes such as El Niño.
Applying their long-term data, the Duke scientists concluded, "the sun may have minimally contributed about 10 to 30 percent of the 1980-2002 global surface warming."
"[Greenhouse] gases would still give a contribution, but not so strong as was thought," Scafetta observed.
Several Forces Affect Temperature
"We don't know what the sun will do in the future," Scafetta added. "For now, if our analysis is correct, I think it is important to correct the climate models so that they include reliable sensitivity to solar activity."
Iain Murray, senior fellow and global warming specialist at the Competitive Enterprise Institute, said the Mars warming adds another level of uncertainty to claims that the Earth's modest recent warming is a result of human activity. "It is probably too much to claim that any one source is the principal driver of the warming trend on Earth," said Murray.
"The number of significant temperature forcings on the climate system grows yearly as we get to know more and more about it, but we really are at a very early stage of our exploration of this very complex system," Murray noted. "If all the estimates are true about the relative effects of forcings like the sun, black carbon, and greenhouse gases, then it is quite possible that we would have been in a sharply cooling phase over recent years were it not for these forcings. In which case, one might say, thank goodness for global warming!"
James M. Taylor (firstname.lastname@example.org) is managing editor of Environment & Climate News.
For more information ...
The September 30 news release announcing the findings of the Duke University research, "Sun's Direct Role in Global Warming May Be Underestimated, Duke Physicists Report," is available online at http://www.dukenews.duke.edu/2005/09/sunwarm.html.