Does Global warming leads to more snow or less snow?


As a matter of common sense, people tend to think that global warming leads to less snow. It’s sounds natural. If temperature gets warmer, snow and ice melts. There’s problem that arctic is melting faster and faster these days. However, interestingly,  not necessary the amount of snowfall always decrease because of global warming.  Global warming sometimes leads to increasing the amount of snow. But why?

Let's see how it snow first. The key is temperature and moisture.

Temperature: there’s goldilocks temperatures for snowing. The heaviest snowfalls occur between 28°F - 32°F (-2.2°C - 0°C)(1).  If the temperature become warm more than certain temperature,It changes to rain. 

Moisture: The air absorbs water vapor and flows toward low pressure. Then, the air expands and the temperature of the air decreases. When the air can’t hold moisture anymore, moisture condenses into the clouds and forms rain and snow(1). Japan is one of the most snowfall countries as  frozen cold wind blows from Siberia in winter and when this frigid air go through the relatively warm Sea of Japan,   Huge amount of water evaporates from surface of the sea and forms clouds.

Japan: One of the major snowest country in the world

In the physics rule, the air is able to hold more moisture when the temperature of the atmosphere gets warmer.(1) That means global warming leads to warmer temperature of the atmosphere and it able the air to hold more moisture. And The more the air hold moisture, the more potential for precipitation.The temperature of sea surface goes up. According to research, the air above the oceans is warmer by more than 1°F and moister by 5% since the 1970s from global warming(1)(2)

Here's the graph of the frequency of heavy precipitation events in the United States. It shows the amount of heavy precipitationn events increases gradually.

This figure shows the percentage of the land area of the contiguous 48 states where a much greater than normal portion of total annual precipitation has come from extreme single-day precipitation events. The bars represent individual years, while the line is a nine-year weighted average. Photo from "Climate Change Indicators: Heavy Precipitation"

So What’s the summary? Global warming leads to the potential for precipitation. But It rains a lot if the temperature doesn’t change to the goldilocks temperatures which is 28°F - 32°F (-2.2°C - 0°C). It have potential to snow a lot in mid-winter but it’ll also be short snowy season. So in the future, the big snowfall place might be shifted to the north and north as global warming proceeds and the place where is goldilocks temperatures for snow shifts to the north.