Not Just Sea Ice, but Snow Cover Affected by Warming
February 23, 2016
Above, one view of today’s temp anomaly as reflected in the University of Maine’s Climate ReAnalyzer.
One of the most powerful “feedback” effects in the climate system is albedo, the whiteness of the planet’s surface.
Where there is fresh ice or snow, the whiteness has a very high reflectivity, and bounces almost all – 80 or 90 percent – of the sun’s energy back to space. When we lose that white surface, absorption of the sun’s heat climbs rapidly, and we see the “vicious cycle” – the positive feedback that’s not so positive for us – as more dark surface = more heat = more dark surface = more heat…
For some parts of the planet, warming can actually mean more snow in the winter, as a warmer atmosphere holds more moisture, which will precipitate out whenever conditions are right.
UPDATE: Have added video interview from Rutger’s Jennifer Francis to help clarify. I’m getting twitter-tacked by deniers suffering from cognitive dissonance.
Rutgers University Snow Lab has some interesting graphs on this topic. Below, take a look at Fall snow cover in the northern hemisphere.A first response is likely to be, “where’s the warming”? Actually, due in part to the increase in open water in the arctic, some areas like Siberia are getting more snow in the fall, as they see a kind of “lake effect” down wind of the newly uncovered water, which sends moisture laden air that way.
Winter shows a similar paradox, with a gradual rise in the snow cover extent.
Where the global change really stands out is in spring snow cover, which is showing the most dramatic change.
As temps warm, spring comes earlier to northern areas, and snow recedes, leaving dark soil and vegetation open to an ever increasing positive feedback.
This year I’ve commented on the remarkable decline in arctic sea ice, right at the time when it should still be climbing to an early march peak.
But the snow cover is also showing the same early decline, as NOAA shows.
We are living in interesting times.