A warming world means milder winters and softer springs. It will also mean fewer blizzards, with milder impacts.
LONDON, 12 June, 2020 – It could soon be safe to think with nostalgia of the snows of yesteryear. Snowstorms in the future in the US could happen less often, with less intensity. And they would be of a smaller size.
This is on the assumption that humans go on burning ever more fossil fuels to release ever more greenhouse gases into the atmosphere to fuel global heating.
Although winters – especially in the central US and on the Eastern Seaboard – will continue to bring snowfall, ice storms and cold snaps, by the end of the century there will be, on average, 28% fewer snowstorms. And with this drop will come a fall of a third in the precipitation of snow or frozen sleet, and the area covered by snowfall will have been reduced by 38%.
A White Christmas will also begin to seem like a happy memory, as winters begin later and spring happens ever earlier.
“If we do little to mitigate climate change, the winter season will lose much of its punch in the future,” said Walker Ashley, of Northern Illinois University.
“Annual reductions in snowfall and snow cover could amplify potential warming”
“The snow season will start later and end earlier. Generally, what we consider an abnormally mild winter now, in terms of the number and intensity of snowstorms, will be the harshest of winters late this century.
“There will be fewer snowstorms, with less overall precipitation that falls as snow, and almost a complete removal of snow events in the southern tier of the United States.”
Severe winters are part of the natural pattern of life in much of North America, and for nearly two centuries meteorologists have observed a pattern of very severe blizzards indeed: sudden calamitous snowfalls that have claimed hundreds of lives and caused billions in damage.
And although temperatures have on average risen, researchers have also repeatedly pointed out that with a rise in average warming comes a greater frequency and intensity of “extreme events”. In a continental winter, any extreme event is usually likely to be harsh. Even if there is less snow over a shorter cold season, blizzards will still happen.
Professor Ashley and colleagues report in the journal Nature Climate Change that they tracked snowstorms for 12 winters earlier in this century: they then used supercomputer simulations to see what would happen to their sample of actual events in a climate that had warmed by around 5°C, the predicted rise if greenhouse emissions go on unchecked.
They ended with a tally of 2,200 snowstorms across central and eastern North America over a map with a grid space of about 4kms, over a period of 24 years – a sequence that embraces the past and the future.
The simulations told a clear story. There would be less snow, across smaller snowstorm tracks, and dramatically fewer falls in the months of October, November and April.
Chicago, Boston and New York will continue to see snowstorms, but the probability of vast snowdrifts and silent streets continues to decrease. Winter travel will become safer and easier, but agriculture and other industries that depend on freshwater delivered by melting snow will feel the cost. So could the rest of the world.
“There are also climate feedbacks to consider,” said Professor Ashley. “Snow cover reflects solar radiation and helps cool the environment. So annual reductions in snowfall and snow cover could amplify potential warming.” – Climate News Network