The most astonishing transportation event of the year will occur on Christmas Eve, but we all know that flying around is bad for the environment, so we have to face an uncomfortable question: How big is Santa Claus’ carbon footprint?

In past Christmas columns for Granite Geek, I have calculated that Santa travels an average of 5.14 million mph and carries 250,000 tons of presents, spending one-five thousandths of a second at each home.

If Santa was using conventional aircraft, this jaunt would consume such a monstrous amount of energy that we’d soon turn into Venus, but he actually uses organic biofuel-powered aerial transportation modules – eight of them, or nine if you count Rudolph.

That doesn’t let him entirely off the eco-hook, however, since ruminants such as reindeer (and cows) have a greenhouse gas weak spot. They eat food we can’t stomach, such as grass, that they break it down in multiple stomachs. The first stomach is the rumen, hence the name.

This breakdown is done by bacteria which as a byproduct produces methane, 20 times as potent a greenhouse gas as carbon dioxide. (Overall, CO2 is a bigger problem for global warming because we produce much, much more of it.)

Each day, full-grown ruminants produce 250 to 500 liters of methane via belching and, if I may be indelicate, farting.

This is no laughing matter, actually. Some estimate that domestic cattle create as much as 2 percent of America’s greenhouse gas emissions from both ends of the digestive system. That’s why eating less meat cuts your carbon footprint.

We will estimate that each of Santa’s nine full-grown reindeer produces the calculated ruminant maximum of 500 liters of methane daily, or one-tenth of a metric ton of carbon released a year, which is the amount of carbon released by 116 gallons of gasoline. Ergo, the nine together produce as much carbon as 1,044 gallons of gas a year.

The average American, if such a thing exists, drives 15,000 miles a year in a 25 mpg car, using 600 gallons of gas annually.

So Santa’s reindeers emit as much carbon each year as one and two-thirds average American drivers.

Considering the trip it takes, that’s pretty darn good. If Santa was a company, he’d issue a press release about “we’re helping to save the Earth,” and probably paint his sleigh green.

Ho ho ho, indeed!

David Brooks can be reached at 594-6531 or dbrooks@nashuatelegraph.com.