But that kind of weather is becoming a new kind of normal with climate change. A new study from Dartmouth, focused on snowpack in the last 40 years across the Northern Hemisphere, shows human-caused warming is having a big impact on winter. In New England, the researchers found, many river basins are losing 10% or more of their snowpack per decade.
Mankin, along with PhD student Alex Gottlieb, set out to study whether climate change has been affecting snowpack in a way that can clearly be attributed to human influence. In places that are very cold, a few degrees of warming won’t have much of an impact, Gottlieb said. Most of the precipitation will still fall as snow instead of rain, and there won’t be big warm spells to melt the snow that is on the ground.
The researchers focused on how river basins are losing snow, studying in particular how the snowpack looked in March – generally the peak of snow accumulation. In about half of the river basins they studied across the Northern Hemisphere, they detected clear trends for snowpack, and in 40% of those they were able to attribute the changes to global warming caused by humans.