This month Harper’s magazine turns its lead essay over to Stephen Stoll, a historian, who in “The Cold We Caused,” delves into the history of climate to show how “nearly incoherent” are the arguments of the likes of climate change denier James Inhofe, Senator from Oklahoma, who continues to insist against the facts that we are in a “cooling period.”

Inhofe concedes that the globe did warm after the Industrial Revolution, but doubts whether this warming was caused by “man-made gases, anthropogenic gases, CO2, methane.”

Stoll turns the question around, asking: What would happen to carbon dioxide and methane if humans were to disappear? As is it happens, we have a reputable (if not indisputable) answer to that question from a scientist named William Ruddiman, at the University of Virginia, who in 2003 published a paper in the journal Climate called How the Anthropogenic Era Began Thousands of Years Ago [PDF].

Ruddiman argues that the so-called Little Ice Age, which took hold from approximately 1315 to 1850, was the result of various horrific plagues and pandemics in the Middle Ages. As people died by the tens of millions, agriculture in much of Europe, Asia, and Central America all but collapsed, forests and jungles regrew, the levels of CO2 and methane in the atmosphere fell, winters lengthened, pack ice spread southward, and global temperatures dropped dramatically. 

Though some climate change deniers have pointed to this as evidence that greenhouse gases are good, Stoll argues that’s a shallow interpretation:

In fact, however, this medieval tale reveals the enormous capacity of human beings to shape their environment, whether unwittingly or deliberately. If our crop-planting, animal-herding, forest-and-savannah-burning ancestors could trigger the rapid cooling of the atmosphere through their sudden absence, then we can achieve the same effect by abandoning other practices. The cold we caused does more damage to Inhofe’s position than any finding by the Intergovernmental Panel on Climate Change.

Stoll sees the positive side of this argument. As the responsibility of wealthy, developed nations for “a just climate” becomes undeniable, “the litany of rationalizations” holding the global poor to blame for their suffering may finally become untenable, giving them a chance to rebalance the scales of justice.

Stoll’s faith in the power of rationality might seem a little naive, except that he foresees a time when “the very poor are filing class-action suits against wealthy nations for reckless carbon output.”

And just this week, according to the Wall Street Journal‘s Law Blog, the conservative Fifth Circuit [Federal] Court based in New Orleans has just allowed lawyers for landowners in Mississippi to file suit against coal companies and oil companies for damage suffered during Hurricane Katrina. The court noted that the Supreme Court has already upheld the right of the EPA to regulate carbon dioxide emissions under the Clean Air Act, and affirmed the causal link between emissions and global warming, and, possibly, ocean temperatures and more powerful hurricanes.

Though no one expects the this ruling on “standing” to lead to quick decisions against coal companies, an expert in class-action suits did predict it would lead to many other claims against emitters being filed. Legal observers recall that the tobacco industry defended itself against damage suits successfully for years, but eventually was forced to stop denying that cigarette smoking is harmful to health.

So Stoll’s argument seems not so far-fetched after all. As they say in courthouses around the world, the mills of the gods grind slow, but they grind exceedingly small.