If climate change is real, how come it was so cold in the Lowcountry last week? Why did it snow in Beaufort County?
The answer, according to University of South Carolina geography professor Greg Carbone, is quite simple. It is winter.
“You could double the amount of carbon dioxide in the atmosphere and you still wouldn’t change the fact that winter happens,” said Carbone, who teaches courses and conducts research on the topics of climate change and climate variability.
During winter, the earth’s northern hemisphere is pointed away from the sun, explained Carbone. Daylight hours decrease and the sunshine we do get is less direct, and therefore less intense. As a result, temperatures drop, regardless of any overall warming trends the planet might be experiencing.
Last week’s cold weather was just that, Carbone said. It was weather, and there is a big difference between weather and climate.
Deke Arndt, a colleague of Carbone who runs the monitoring branch of the National Oceanic and Atmospheric Administration’s National Centers for Environmental Information, describes the relationship between weather and climate using a boxing analogy.
“If you think of the movie ‘Rocky,’ climate would be like Mickey, Rocky’s trainer, and weather would be like Rocky,” said Carbone, describing Arndt’s analogy. “Rocky in the ring throwing punches is immediate and unpredictable. From minute to minute Rocky can do anything, but what he does will be influenced by Mickey’s training. If he had a different trainer, he would fight differently.”
Basically, due to the unpredictable nature of weather, the odd cold week or the occasional freak snow storm will eventually happen, but that doesn’t change the climate patterns underlying them.
Some scientists even believe that intensely cold weather could itself be proof of climate change.
A climate study published in May of 2017 by WIREs Climate Change contends that arctic ice, melting at an increased rate due to climate change, has allowed the jet stream to wander from the arctic further south, bringing colder air with it.
Carbone said that the science behind this theory is still emerging. However, the science describing the effect that warming has had on the last two hurricane seasons is more firmly established, and over the last two years the Lowcountry has seen that effect first hand.
Hurricanes are fueled by warm water, said Carbone, and as the planet has been heating up there has been more fuel for storms like Matthew and Irma, which hit the Lowcountry, and also for storms like Harvey and Maria, which devastated Houston and Puerto Rico, respectively.
The Union of Concerned Scientists, in an article on their website, discuss the mechanisms by which warming increases hurricane intensity.
“Warm air holds more water vapor than cold air — and the rising air temperatures since the 1970s have caused the atmospheric water vapor content to rise as well. This increased moisture provides additional fuel for hurricanes,” says the article. “Second, as ocean temperatures rise, there is also less cold, subsurface ocean water to serve as a braking mechanism for hurricanes.”
Coastal flooding is also on the rise, according to a release from the National Weather Service in Charleston. This is due, for the most part, not to the tidal influence of the moon or from weather events, but to a rise in ocean levels, and it only makes things worse when hurricanes impact Beaufort County.
“As global temperatures rise/warm, large land ice masses, such as Greenland and Antarctica, melt, pushing more water into the oceans,” said the weather service release. “Rising temperatures also cause a warming of the Earth’s oceans, forcing the ocean surface to ‘sit higher’ than if it was cooler. This higher “water/sea level” makes it easier to flood the coast.”