How worried are you by the declining Arctic?

arctic sea ice in sharp decline year: last week, scientists announced hit lowest point ever measured, shattering previous record.

turns out that's not dramatic change in arctic. study canadian researchers finds springtime snow melting away faster arctic ice. has profound implications earth's climate.

springtime snowmelt matters lot: determines when spring runoff comes out of mountain fill our rivers. , chris derksen @ environment canada in toronto says snow reflects sunlight space, helping keep earth heating fast.

"when remove snow cover form land surface, when remove sea ice ocean, take away highly reflective, bright surface, , expose bare land or tundra underneath, , absorbs more solar energy," says.

darker land traps heat , warms planet. scientists have been keeping eye on trend years.

derksen , colleague ross brown have produced study, has been accepted publication in geophysical research letters, documents dramatic increase in speed of snowmelt. turns out in may , june, snow across far north disappearing fast.





we're losing spring arctic snow cover @ rate faster models predict.



- chris derksen, environment canada

"it's decreasing @ more rapid rate summer sea ice," derksen says. "so loss of snow cover across arctic big issue loss of sea ice."

derksen expected see gradual decline, taken aback when reviewed satellite measurements past 5 years , saw speed of loss. snowmelt decline occurring @ rate of 18 percent per decade, versus 11 percent per decade talked arctic sea ice.

"that bit shocking," says.

it's contrary scientists had predicted. there more dozen research groups around world use computer models , simulations forecast how things change in our warming world.

effects of melting snow

"we're losing spring arctic snow cover @ rate faster models predict," derksen says. , "puts question scenario 10, 20 or 30 years now."

today, spring snowmelt of concern biologists study life in far north. syndonia bret-harte @ university of alaska, fairbanks, says change affects rivers spawning fish rely on.

hastens melting of permafrost, layer of frozen soil contains lot of carbon. , when permafrost melts, releases greenhouse gases atmosphere. , there's matter of fires in boreal forests.

"if things dry out faster in spring, can more fires, , that's trend see in recent years, increased fire frequency , size of fires," says bret-harte.

, while far north feeling these effects strongly, says affect us, too.

"since arctic acts air conditioner ... rest of northern hemisphere, heating in arctic going cause feedbacks heating in more southern climate."

researchers global warming no doubt contributing melting of spring snow. , philip mote @ oregon climate change research institute says there may relationship between rapid loss of sea ice , snowmelt.

spring snowmelt "may set arctic absorb heat , melt sea ice faster, late summer, time of year, can see low levels," mote says.

there's 1 big difference between snowmelt , sea ice melt. because sea ice getting thinner , less resilient every year, seems inevitable melting trend continue. mote says long-term buildup of greenhouse gases may not whole story spring snowmelt.

"the atmosphere , ocean different things year year, , can affect snow cover in ways independent of greenhouse gases," says.

mote not sure dramatic trend of recent years keep on downward spiral. said, long-term trend clear: less snow, less ice , more warming.

arctic sea ice in sharp decline year: last week, scientists announced hit lowest point ever measured, shattering previous record. turns out that's not dramatic change in arctic. study canadian researchers finds springtime snow melting away faster...

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