SNOW was the subject of a discussion on climate change in the US Senate last February; it was nothing serious. To help make his case that people cannot be influencing the climate, Jim Inhofe, a Republican from Oklahoma, cited archaeology and scripture. Then he produced a snowball, and said, “I ask the chair, do you know what this is? It’s a snowball, just from outside here. It’s very, very cold out.” Glorying in his idiocy, Mr Inhofe, who was chairman of an important environmental committee at the time, then tossed the snowball at his Republican colleague.



With Washington currently under two feet of snow, this episode is worth remembering for two reasons. First, because the ignorance, wilful or otherwise, many Republicans display on global warming is not dissipating. The frontrunner for the GOP nomination, Donald Trump, claims global warming is a conspiracy cooked up by the Chinese to destroy American industry. His closest challenger, Ted Cruz, a senator from Texas, also says it is a hoax , but reckons the “liberal left” is to blame. Ben Carson, a retired neurosurgeon and former front-runner, had this to say: “There is no overwhelming science that the things that are going on are man-caused and not naturally caused. Gimme a break.” This was one of many episodes during the campaign in which Mr Carson, despite his extraordinarily distinguished medical record, has suggested you do not really need to be a brain surgeon to be a brain surgeon.



A clutch of more plausible Republican candidates, including Marco Rubio, a senator from Florida, and a trio of current and former governors, John Kasich, Chris Christie and Jeb Bush, take a slightly more serious view of the problem. All have acknowledged, when pressed, that they accept the science; none has anything terribly constructive to add to that. Mr Rubio offers a circular argument for doing nothing much: there is no point America trying to cut its emissions unless other countries do the same, and even if they say they will, they won’t. He promises to withdraw America from the UN agreement on curbing emissions signed in Paris last month. Mr Rubio, Mr Bush and Mr Kasich also promise to scrap a suite of new regulations to cut emissions from coal-fired power stations, known as the Clean Power Plan—which is probably essential to America’s compliance with the Paris agreement.

The second reason why Mr Inhofe’s stunt is worth recalling is that, were it repeated today, it could, tentatively, be argued that the snowball was evidence of global warming. Ascribing single weather events to climatic changes is almost as dodgy science as Mr Inhofe’s. Nonetheless, taking a longer view of the weather record, some researchers say there is “moderate evidence” to suggest an increase in both the frequency and intensity of winter storms in the Northern Hemisphere since 1950.

Climate science supports that. Because a warmer atmosphere holds more moisture, roughly 7% more per 1ºC of temperature increase; and the world is already about 1ºC warmer than it was in pre-industrial times. So extreme precipitation events, such as Winter Storm Jonas, which has swept north-east America, from Southern Virginia to New York City, may well become more common.

The storm may also have been influenced by El Niño, a climatic event under way since the middle of 2015. Named after the Christ-child, it sees warm water, collected over several years in the western tropical Pacific, slosh back eastwards when winds that normally blow westwards weaken, or sometimes go into reverse, roughly every two to seven years. This affects weather systems around the world. In America, it causes more west-to-east flows of jet-stream winds than is normal across the country. This and other typical effects result in a stormy winter for California and the South, and generally less tempestuous conditions for the North. But each Niño “has its own flavour” according to Kevin Trenberth of America’s National Centre for Atmospheric Research.

In any event, Jonas has caused havoc. It has grounded thousands of flights, jammed freeways and killed at least 14 people. More than three feet of snow has fallen in four states. It could be among the most powerful recorded storms to hit America’s north-east. On the primary trail, its fallout has been lesser: mainly a dreary argument over whether Mr Christie should or would interrupt his campaigning in New Hampshire to see out the storm in his snow-struck state. With great reluctance, he ended up nipping home for it.