Hey all! I hope you’re enjoying your snow day (for those of you who don’t yet know, UVA got the entire day of school cancelled, which was pretty nice considering I had a midterm today haha). My roommate came home this morning, told me school got cancelled, and my heart soared! ANYWAYS back to the main topic. And for you people who are short of time, read the bolded fragments for a “tl;dr” version of the article!
*Disclaimer: this is an article about snow, so the images are going to be beautiful. :)*
Global warming means more snow?! What? How does that make any sense? Why would an increase in temperature lead to an increase in snowfall? Shouldn’t it be the other way? Well ladies and gentlemen, I thought the same thing. But the truth of the matter is that it does mean more snow. And here’s why:
First let’s discuss how water gets in the air. Water vapor is usually lifted into the atmosphere by storms that accompany warm and cold fronts. (Warm front = warm air passes over cool air. Cold Front = cold air pushes underneath warm air). So as this water vapor is rising / finding its place in the atmosphere, it starts filling up the carrying capacity for moisture in the atmosphere.
So now the water is moisture in the air. The amount of moisture that can be held in the atmosphere is directly related to the temperature of the air. So that means that an increase in temperature leads to a possible increase in the moisture of the air. In fact, about one degree Fahrenheit corresponds to a 4% increase in the atmosphere’s moisture-holding capacity. At 50°F (10°C) the water-holding capacity of air is double that at 32°F (0°C). How about that?
So why is this important? Well, more temperature means more moisture means more precipitation. And remember, because higher temperatures correlate to higher amounts of moisture, the temperatures just below the freezing point will have the strongest snowfall. This range of temperatures (about 28°F to 32°F) is known as the Goldilocks range as its weather conditions are just right for massive amounts of snowfall. That makes sense, right? If there’s more moisture in the atmosphere at these temperatures, but it’s just cold enough that the precipitation takes the form of snow instead of rain, that range will have huge snowfall! So when global warming increases overall surface temperatures, it increases the amount of moisture in the air and thereby increases snowfall when conditions are below freezing. Of course, conditions do still need to be below freezing for it to snow at all. And while it tends to be warmer near the beginning and end of the winter season (meaning rain instead of snow), due to the overall increase in atmospheric moisture capacity as well as the fact that increased moisture can amplify the storm itself, those fewer times in winter where it does snow, it really does snow. A lot.
So if y’all are enjoying your snow day, you’ve got Global Warming to thank!
But in all seriousness, basically I’m saying that essentially global warming is leading to more massive and more irregular precipitation. This means more intense droughts and stronger floods. Wildfire risk goes up. Natural disasters in general increase in both probability of occurring as well as intensity when they occur. The USA is already experiencing this (which makes sense as the USA is one of the major contributors for carbon dioxide emissions to the atmosphere). If anyone remembers “Snowmageddon” from 2010, we received an insane amount of snowfall. This is because the temperature of the air was approximately 3°F higher than usual, so the moisture in the air was around 12% higher than normal! And because it wasn’t hot enough that temperatures rose above freezing, the snowfall was ridiculous, dangerous, and costly. The storm came at the right time because conditions were just right. And the more global warming continues, the more frequent these conditions will arise and, similarly, the more frequent these storms will be.
So to wrap things up: contrary to popular belief, global warming is actually promoting these crazy snowfalls for now.