I hope the alarmist kooks don't go to mars, because Martian global warming is bound to scare them to death!
Which brings up a very good point, and that is Martian Global Warming.
..which, to the extent it's occurring appears to be due to *very* different factors than Earth's, e.g. regional climate instability affecting its ice caps (which are made mostly of *carbon dioxide*, not water), and changes in the planet's reflectivity (albedo).
We've only been measuring Martian weather for about three decades, over which time the trend, if one can call it that, is a *cooling* one. The fact is we simply don't have anything like the time series of weather and climate data for Mars, that we have for Earth, for making comparable claims.
Now that mars has been studied at very close range for several years now, it is a known fact that mars is also experiencing the same global warming trends as found here on earth.
As far as comparing trends, factors affecting Martian atmospheric dynamics are notably different from Earth's, including significant impact of nearly planet-wide dust storms, and significant absence of those rather large bodies of water we call oceans.
What the earth and mars do share is the sun...whose possible impact on global warming was evaluated in the most recent IPCC report...and guess what it found? I challenge you to look it up.
Also, latest research (published this April in Nature) suggests that any 'global' warming on Mars is due to recent changes in albedo -- that is, its reflectivity.
Not the sun.
Fenton, Lori K.; Paul E. Geissler and Robert M. Haberle (5 April 2007). "Global warming and climate forcing by recent albedo changes on Mars". Nature 446: 646-9.
Actually their use of 'global warming' is regrettably literal, since it most likely applies more to a short-term phenomenon. As one atmospheric scientist commented in
the news article accompanying the Nature paper,
http://www.nature.com/news/2007/070402/full/070402-5.html
Using these results, one might come to the conclusion that in 500 or so years the martian polar ice-caps will be completely gone, notes Phil Christensen, a planetary scientist at Arizona State University, Tempe. But, he says: "I don't think that's likely. They're looking at a piece of the cycle, other processes could turn this around to a place where the ice-caps start growing again."
A major dust storm that engulfs the entire planet, for example, could redistribute dust more evenly around the planet and instigate cooling. "Dust storms are like a reset mechanism," says Fenton. Such storms were seen on the planet in the 1970s.
Fenton's work shows nicely how conditions on Mars have changed on decadal timescales, says Christensen. But the results shouldn't be taken further than that: "You can't take 10 years of data and extrapolate out to 1,000 years," he says
and later in that Nature news article
The warming on Mars is likely to be seized by climate-change sceptics here on Earth - if Mars is hotting up even without any cars or pollution, then perhaps the Sun or some other natural, Solar-System-wide factor is to blame. But to infer that would be "crazy" says Christensen (see 'Hot times in the Solar System').
"The more we learn about Mars, the more intuition it gives us about Earth, but the systems are fundamentally different," he says.
In the same issue, Nature also published a specific debunking of the skeptical denialist propaganda about solar system heating being the cause of 'our' global warming -- the ''Hot Times in teh Solar System' articel mentioned above. Here's an excerpt
http://www.nature.com/news/2007/070402/full/070402-7.html
Before we take a quick spin around the Solar System looking at these ideas, it is worth noting that the said system contains, in all, ten bodies with atmospheres thick enough to provide something we might call a climate. If these ten climates are all subject to a little natural variation, as the climate on Earth is, then finding that half of them are showing some warming at any given time is hardly surprising.
It is also worth noting that the Sun's radiance is measured from Earth orbit, and these records do not show it increasing over the past few decades, except with the regular rise and fall of the solar cycle. This second fact, you might think, should be enough to scupper the theory about system-wide solar warming on its own; strangely it is notably absent from accounts of the matter.
Moving on to the particulars, in the cases of Pluto and Triton, Neptune's largest moon, the observed warming is due to their current orientation to and distance from the Sun — technically known as summer.
Pluto was closest to the Sun in 1989 and is now moving away, but it is still relatively close. It's not that surprising for the greatest warmth to come a little after the closest approach, any more than it is for afternoons to be warmer than noons. And Triton's orbit is giving its southern hemisphere a particularly hot summer, boiling off frozen material from the southern pole and thickening the atmosphere, keeping in even more heat.
On Jupiter, things are a little different. The patterns of circulation seem to be changing, such that heat at the equator is stuck there, and higher latitudes are getting a little cooler.
On Mars, the warming seems to be down to dust blowing around and uncovering big patches of black basaltic rock that heat up in the day (see 'Mars hots up'). No change in sunshine required.
To take this disparate hodge-podge of phenomena and try to construct a theory of solar influence from it is the sort of foolishness people get driven to when desperate to support a failed theory, or just for a chance to muddy the waters.
But you wouldn't be aware of any of this because you don't consult actual scientific journals and sources to find about about global warming, do you?
At best you read dubiously-reported 'science news' article in the mass media, or stick strictly to the denialist websites and right-wing talk-radio,, right?
