Marvin and Mars

The Red Planet is / is not running a temperature

© Bryan Zepp Jamieson
http://www.mytown.ca/zepp
3/18/06
 

Regular readers know that a theme I write on fairly often is that of global warming. Next to nuclear holocaust or an asteroid strike, I consider it the most serious threat humanity faces, and unlike nuclear war, it is inevitable, and unlike an asteroid strike, we know that it’s going to happen. Some of us will live to see the worst effects of it.

I also like to talk about Mars. Like anyone raised on a diet of Ray Bradbury, Robert Heinlein and Edgar Rice Burroughs, I’m fascinated by our closest neighbor, and this shows up from time to time in my pieces.

It’s not often I get to talk about both at the same time. In fact, this is the first, and probably only time. So I’m going to make the most of it.

Last week, I wrote another piece about global warming, and mentioned toward the end about how tenaciously right wingers clung to the ideology that global warming is nothing but a plot by America-hating, tree-hugging Luddite liberals who hate capitalism. They do so long after insurance companies and extraction industries have stopped trying to pretend global warming isn’t real, and some have even stopped pretending human activity has nothing to do with it.

So in the next couple of days, I heard from a couple of right wingers, both of whom wanted to use Mars as an example in order to set me straight on this whole liberal fantasy about global warming.

One wanted me to know that there was runaway global warming on Mars, that the ice caps were melting, and since there were no humans on Mars (except perhaps for Dan Quayle, who might not be human) then it was obvious that human activity wasn’t what was causing global warming.

Now, the OTHER right winger wanted me to know that despite the fact that Mars had even more CO2 than earth, there was no sign of global warming on Mars. Therefore, the implication was that CO2 buildup couldn’t be what was causing global warming on Earth.

Hrrrrm. I see.

I think we may have learned more about right wingers than we have about Mars, even though both are pretty alien to our experience. But I promised to talk about global warming and Mars, which is a lot more interesting and fun than right wingers, so let’s talk about that.

A few years ago, there was some scientific speculation that Mars was coming out of an ice age. This was based on the presence of water (ice, actually) at equatorial latitudes, suggesting a retreat of ice caps. Mars’ current climate, it was argued, couldn’t support the presence of ice where it was, which suggested that in the recent past, it had been substantially colder. Of course, Mars’ present climate doesn’t really explain the presence of the ice caps (which were once supposed to consist of frozen CO2, but which have turned out to be mostly frozen water).

Since then, we’ve learned that Mars is far wetter than anyone dreamed, with large areas of subsurface areas of water, including one area so big that it could be charitably described as an underground ocean. It is roughly the size of Lake Superior, and is believed to be about 50 meters deep, which is a sizeable amount of water.

Then, too, the sparse data from Mars doesn’t show much in the way of climate change. With virtually no weather, the day time high and the nighttime low fluctuate in any given spot only as a result of the seasons changing. Mars’ axial tilt is slightly more pronounced than Earth’s, and the year is nearly twice as long, so if you think winter is too long and too cold where you are now, then Mars probably isn’t your cup of tea. Of course, if humans ever colonize Mars, then it might experience global warming. Only there, that wouldn’t necessarily be a bad thing.

But there is no evidence of global warming on Mars. Nor is the sun getting hotter. In fact, we’re at a solar minimum right now in the sun’s 11 year cycle, although the next maximum, due sometime around 2010 or 2012, is expected to be a doozy. Aurora Borealis in Mexico City, cell phones melting down everyone’s brains, all that neat stuff. But for now, the sun is reasonably quiet.

That brings us to the issue of Martian CO2. This has nothing to do with how many root beers the mascot of the Ottawa Senators can chug. [For those of you who aren’t hockey fans, or have never heard of Ottawa, the team mascot is Marvin the Martian, of “Looney Tunes” fame].

Mars has CO2. Quite a bit of it, considering. Ninety-five percent of Mars’ atmosphere is CO2, compared with earth, where .038% of the atmosphere is CO2. And in fact, there is a greenhouse effect: the surface of Mars runs about 4 to 18 degrees (Fahrenheit) warmer than it would if it didn’t have an atmosphere at all. This is of scant comfort, since it still averages about -120F., a temperature even the Ottawa Senators would find depressing.

The claim that Mars has “more CO2 than Earth” is not particularly true. It’s one thing to say that the air is nearly all CO2, another to say there’s much in the way of air. For one thing, the Martian atmosphere at the surface is only about 1/180th as dense as Earth’s. You would have to go up twenty-five and a half miles to find air as thin as the Martian surface. At that point, 99.4% of the atmosphere lies below you. Due to the deeper gravity well and higher starting pressure, Earth’s atmosphere also extends out further from that point than Mar’s does from the surface (Mons Olympus, Mars’ biggest mountain, peaks out in an effective vacuum), and encompasses a globe three times as big. So earth has a LOT more air than Mars, more than enough that in fact, Earth has more CO2 than Mars.

The greenhouse effect is more pronounced here, too. Earth is closer to the sun, and receives roughly four times as much solar energy per square mile as Mars. Then, too, with Earth’s greater surface area, that makes for 12 times as much solar energy hitting earth as what hits Mars.

If Earth’s atmosphere was 95% carbon dioxide, we would have a climate quite similar to Venus, which runs between 600 and 800 degrees. Venus is what real estate agents would call “a real dog of a property.” So we might want to consider avoiding pushing the CO2 levels up to 95%. It’ll really screw with the property values.

So if you are discussing global warming, and some right winger says, “but Mars...” you can counter either of the contradictory arguments they present to prove there is/is not global warming on Mars.

And think of Marvin next time you pop a carbonated beverage.