Nearly a century later, environmentalists are thinking the same way about carbon. Converting fossil fuels into controlled substances today could lead to outright carbon prohibition tomorrow.
In a magazine interview last year, Al Gore upped his call for a 90 percent cut in fossil fuel use, demanding Congress “eliminate the payroll tax and replace it dollar for dollar with a CO2 tax.” A research paper published this year in Geophysical Research Letters went further. “Avoiding future human-induced climate warming,” the authors said, “may require policies that seek not only to decrease CO2 emissions, but to eliminate them entirely.” As the New York Timesbusiness section headlined it in March, “For Carbon Emissions, a Goal of Less Than Zero.

Those who view fossil fuel the way Carrie Nation did Demon Rum point out that were everyone on Earth to burn just a gas tank’s worth of carbon each day, CO2 in the atmosphere would still double in a decade. Skeptics may discount climate models as metaphysical, but true believers consider the human costs of prohibition an acceptable price for environmental salvation. Gore’s 2006 Nobel Prize speech elevated environmentalism from a pretext for social intervention to a categorical imperative by declaring: “We must abandon the conceit that individual, isolated, private actions are the answer.…They will not take us far enough without collective action.”
It took two centuries for daily per capita carbon consumption in America to reach the roughly 100-pound level that currently lights homes, powers industry, and keeps the Internet humming. But like driving, all those welcome activities increase the concentration of carbon dioxide in the atmosphere. The average American currently generates 22 tons of CO2 a year, but to limit 21st century warming to 2.5 degrees Celsius, the Intergovernmental Panel on Climate Change suggests cutting the global rise in CO2 to one part per million by 2050. That’s only a small multiple of the weight of the CO2 people exhale, and realizing this goal within 42 years could require America to burn less carbon in a month than we do now in a day.
This draconian downturn unfolds from a single statistic: the 5-quadrillion-ton weight of Earth’s atmosphere. Your 792,000-ton share of the air may seem hefty, but one part per million of it is less than one ton. Goodbye, central heating; an average New England home furnace belts out six tons of CO2 a year. Ditto private cars; families living on a truly Earth-friendly carbon ration might spend breakfast debating whether to blow their half-pint gasoline coupon on a moped ride to town or use the daily kilowatt-hour allotment to turn the communal electric blanket up to 4. Holiday turkeys may end up as sashimi, since oven roasting could mean a heatless Thanksgiving night or Christmas Eve.
A personal CO2 limit of less than a ton per year does not even imply the right to buy that much fuel, because CO2 is only 27 percent carbon. Multiply your 1,745-pound annual CO2 ration by 27 percent, divide the result by 365 days, and…yikes! It’s 21 ounces of carbon a day—and falling. If the global population reaches 9 billion by 2050, expect a daily fossil fuel ration of a latté cup of gasoline, three Pilates balls of natural gas, or a lump of coal the size of a turnip.
If you suspect life on a pound of coal a day might be solitary, brutish, nasty, and short, you’re right. The countries with the smallest carbon footprints already feature the shortest life expectancies on Earth. Not that real prohibitionists should mind—when it comes to alcohol,  Sudan is bone dry.