not surprising As the earth warms, we will lose snow.what teeth What is surprising is that this loss is not simply the result of an increase in greenhouse gases that heat the atmosphere, but rather an increase in particulate pollution from fossil fuels. When small pieces of black carbon fall onto the snow, the snow turns black. The snowpack absorbs more of the sun’s energy, becomes warmer and melts faster.
A new model suggests that reducing fossil fuel combustion has a two-to-one benefit for the ailing snowpack: lower temperatures of the snow surface and surrounding air. “We’re starting to see a decrease in these small particles in the air, and they’re going to have an immediate impact on snowpack,” said Ruby Leung, a climate scientist at Pacific Northwest National Laboratory who co-authored the recent paper. he says. paper Description of modeling in nature communications. “As the air gets cleaner, we expect the snow to become whiter and cleaner.”
Clean snow is less likely to melt. Freshly fallen snow is one of the brightest natural surfaces on Earth, reflecting 90% of sunlight. “The buildup of black carbon on the snow essentially pollutes the snow,” says climate scientist Lawrence Madrik. the study He studied snow at Environment and Climate Change Canada but was not involved in the new paper. “And that increases the amount of snowmelt that occurs, because dark surfaces absorb more light and get warmer faster.” (As opposed to wearing a black shirt, which absorbs the sun’s energy.) , think about how hot you feel outdoors when you’re wearing a white shirt that reflects the sun’s energy.)
This melting is of particular concern to the two billion people who rely on the world’s snowpack for a reliable water source. Unlike rain, which immediately flows into a reservoir, snowpack releases water slowly as winter turns into spring and summer. This tends to provide more water than regular rain, much of which is lost when it percolates into the ground. (Unless you intentionally recharge an aquifer with rainwater and use it later for drinking water.)
“People don’t necessarily know where their water is coming from, because they’re downstream from where snow and ice accumulates and melts,” says glaucologist S. Mackenzie Skiles. To tell. the study studied the effects of pollutants at the University of Utah but was not involved in the new paper. “In the western United States, up to 80 percent of our water resources come from snowmelt, depending on how close we are to the mountains.”
Globally, climate change has warmed the air and reduced snowfall. Spring snowfall occurred from 1955 to 2020. decreased by 20% Crossing the American West. Less snow and ice means warmer areas, Faster. “Due to climate change, snowpack is melting days to weeks earlier,” Skiles said. “There’s something of a double whammy here: the snow is denser, which absorbs more sunlight. But at the same time it’s melting faster, leaving behind a darker ground cover. exposed and it absorbs rain. many Let’s get more sunlight. ”
