 |
 |
Ice Caps Melting
Name: James
Status: Other
Age: 30s
Location: N/A
Country: N/A
Date: N/A
Question:
Three questions:
1) Can you confirm the report below; has the Arctic polar ice cap
really melted?
2) Weren't there government measurements published just last November
that suggested the ice cap would not melt for another thirty-five years?
3) Can you extrapolate this to predict how long it will take Antarctica
to melt, please? What is your best current estimate?
I look forward to your answers!
Sincerely,
James Salsman
Replies:
James,
The polar ice has thinned some 30-50% in the last 40 years.
This may be a result of warming of the atmosphere, but the
warming in the past century has been so small (0.5 degrees C)
that it cannot explain the thinning. A natural cause of another
kind, such as a change in polar ocean currents is quite possible.
Leads (openings in Arctic sea ice) are common in the summer,
with the ice forming into essentially icebergs that move around
and smash into each other with the Arctic ocean currents. That
there was a lead a mile wide may be unusual, but is not
impossible even in the coolest of summers in the Arctic. The
report is overblown, as many media reports are.
An interesting sidelight to this is that at Barrow, Alaska it
is pretty much ice-free this time of year, but a few weeks ago
the sea ice closed in (early this year). So, you can see that
it has not been a normal summer in the Arctic.
The article that you copied is undoubtedly inaccurate in stating
that there hasn't been open water at the North Pole in 50 million
years. The climate has been much warmer than now, much more recently
than that. So, wide leads may have been fairly common during
some of the warmer climate periods.
David Cook
(a meteorologist working at Argonne National Laboratory)
Click here to return to the Environmental and Earth Science Archives
| |
Update: June 2012
|
|
