This past Halloween, we approached a curious jack-o’-lantern with the solitary number 350 carved into its flesh. A bright-eyed man emerged from the tiny home behind it. My kids yelled “trick-or-treat!” He dropped some candy in their buckets. And then, I asked the question that he’d obviously been waiting for:
What’s with the 350 pumpkin? Is that your house number?
After a brief dramatic pause, the man spoke passionately of greenhouse gasses and global warming, the well-intended but woefully-inadequate Kyoto Protocol, and that we must swiftly reduce atmospheric carbon dioxide to a level that scientists have determined will spare the planet:
350 parts per million!
We thanked “350 Guy” for the information and candy and continued on our way.
Later, to avoid another such embarrassing intellectual faux pas, I began to bone up on my climatology. Now, for example, I know that the fraction of carbon dioxide in the atmosphere has risen from a pre-Industrial 280 parts per million (ppm) to around 390 ppm today.
Some straightforward calculations reveal that this additional 110 ppm of CO2 amounts to a mass of 564,000 metric megatons and volume of 437,000,000 gigaliters – the shocking equivalent, per capita, of one bubble of pure carbon dioxide, 163 feet in diameter, for each man, woman, and child on the face of this earth (*):
That’s 6.8 billion enormous spheres of greenhouse gas, each large enough to swallow the entire 129-foot length of a Boeing 737-800 airliner with room to spare.
On that note, please allow 350 Guy and Yours Truly to announce a collaborative effort – our Fall 2010 line of giant-CO2-bubble jack-o’-lanterns – coming in five months to a front porch near you!