Your mission: (Answer this for me plz)

Question

1. You are a climatologist who has been given the task of finding out how much glaciers and ice caps have receded over the past 50 years.

2. You have at your disposal satellite image data from this entire time period.

3. Describe, step by step, how you would go about giving your superiors the information they want.

Answer 1

Bering Sea water temperatures are warming up to 3 or more weeks earlier in spring and freezing later in the fall reducing time for sea to form. This has allowed some sub-Arctic species of fish to move north and forced Arctic species even further north into the Arctic. (recent issue of the Journal of Science)

Warmer waters are moving north into the Northern Bering Sea, melting sea ice and pushing walruses, polar bears, and some diving seabirds further north.

The Arctic Ocean’s summer sea ice has been shrinking for decades.  Researchers from NASA detect a loss of 2.05 million square miles of ice in Sept 2005; the largest loss on record. Sea ice losses are now at about 8.5% per decade, according to NASA. Climate models predict 50-60% of sea ice being lost by 2100. Another model predicts that by 2070 the Arctic Ocean will be ice free.

More ice-free waters are expected to exacerbate local warming trends because water is darker than ice and absorbs more solar energy than sea ice and snow, which reflect sunlight back into space.  Same concept with why you wear a white tee-shirt rather than black on a hot summer day.  

In the last 10 years, scientists have become aware of a dramatic increase of melting glaciers in both the Arctic and parts of the Antarctic.  The ice caps in Greenland and Antarctica together contain enough ice to raise the sea levels to about 200 feet.  A total meltdown is unlikely, but with more than a fifth of humanity living on less than 2 feet above sea level is a sign of disaster globally.

Once warmer air and water have caused a tidewater glacier to thin and float off the seabed, there’s nothing holding back the mass of ice uphill and the glacier pours ice into the sea at an alarming rate.  Even though the glaciers’ fronts are retreating, the ice in the glaciers are moving into the sea faster than ever, gradually thinning and depleting the entire glacier.

The retreat of tidewater glaciers is plainly visible from the ground as well, where ice has been stranded on what are now shorelines of open fjords.  

NASA scientists are using a radar satellite to track a domino-like collapse of glaciers from south to north along both eastern and western coasts of Greenland.  In the last 5 years, the collapsing trend has moved north 300 miles according to recent study in the journal Science. Similar glacier retreat is underway in southern Alaska.

New research shows Greenland’s coastal glaciers are now retreating many meters per year and disgorging ice into the sea at several ties their normal rates.  They are not just bursts.  These glaciers have never come back to normal.

With all this being said about what is going on in the North Pole.  Let’s now take a good look at what is happening to the South Pole and why it is a significant series of events.  This continent isn’t only isolated geographically, also it’s often guarded by a ring of ocean and atmospheric currents that can keep out water and air from the rest of the world.  For this reason, it’s only the narrow and more northerly Antarctic Peninsula that is seen significant warming so far.  The rest of the continent is giving scientists mixed signals (some parts are losing ice and others are gaining ice).

A recent and exhaustive aerial and satellite study published in the journal Science found that 87% of the 244 coastal glaciers on the Antarctic Peninsula have retreated over the past 50 years. In the 1950s, only those at the northern tip of the peninsula were retreating. But that trend has spread south.

In East Antarctica, there is a general warming of the middle atmosphere of about 1.25 degrees F per decade over that last 30 years.  It’s less clear that means in terms of what might happen to Antarctica in the future.  This may come to a very unfortunate dark time for all of us.

Elsewhere in Antarctica it’s less clear if there is any trend in the glaciers. Some are growing and others are shrinking.  Most models predict this slow climate response in Antarctica.  Part of the reason for it is that the continent is physically isolated from the rest of the globe.  In winter even Antarctica’s air doesn’t mix with the rest of the atmosphere.