Global Warming – Climate Change

Who Cares?

image at: communities.canada.com/vancouversun/blogs/the...

Global Warming – Climate Change

Who Cares?

However - this is a Scientific problem and Science deals only with evidence and assessment of evidence to the best of our honest (disinterested) ability.

4/5

at: www.personal.psu.edu/ebt5007/hmwk3.html

NOW

http://www.coolantarctica.com/Antarctica%20fact%20file/science/Mauna_Loa_Carbon_Dioxide.png

+0.8oC

since

1860

The Arctic may be ice free by 2040 - the first time in a million years.

1979 2004

The Arctic ice cap has shrunk over the last four years

The areas of Greenland that melt in summer have expanded (orange) in recent years.

Arctic Climate Impact Assessment

1992 2002

McCarty Glacier in Alaska. Evidence of global warming?

Triftgletscher in Switzerland until recently filled the entire basin seen here. Thinning of the tongue during the 1990s accelerated and as of 2001 a lake started to form in front of it. Rapid break-up of the snout is now underway. Image: Glaciers Online/Jürg Alean

Trift Glacier - Oberland Switzerland showing glacier retreat

1948 2002 2006

at: www.personal.psu.edu/ebt5007/hmwk3.html

This graphic shows the height of the Greenland ice sheet at present (left) and during the last interglacial (about 130,000 years ago),

The CCSM suggests that during the interglacial period, meltwater from Greenland and other Arctic sources raised sea level by as much as 11 feet (3.5 meters),

However, coral records indicate that the sea level actually rose 13 to 20 feet (4-6 meters) or more probably due to Antarctic melting

This might be accelerated by global-scale greenhouse-induced warming year round,

In the last few years sea level has begun rising more rapidly, now at a rate of about an inch per decadeRecent studies have also found accelerated rates of glacial retreat along the margins of both the Greenland and West Antarctic ice sheets.

at: www.personal.psu.edu/ebt5007/hmwk3.html

This graphic shows the height of the Greenland ice sheet at present (left) and during the last interglacial (about 130,000 years ago), as simulated by the NCAR-based Community Climate System Model coupled with an ice-sheet model. (Illustration courtesy Bette Otto-Bliesner, NCAR.)"Getting past climate change correct in these models gives us more confidence in their ability to predict future climate change," says Otto-Bliesner.The CCSM suggests that during the interglacial period, meltwater from Greenland and other Arctic sources raised sea level by as much as 11 feet (3.5 meters), says Otto-Bliesner. However, coral records indicate that the sea level actually rose 13 to 20 feet (4-6 meters) or more. Overpeck concludes that Antarctic melting must have produced the remainder of the sea-level rise.These studies are the first to link Arctic and Antarctic melting in the last interglacial period. Marine diatoms and beryllium isotopes found beneath the West Antarctic Ice Sheet indicate that parts of the ice disappeared at some point over the last several hundred thousand years.Overpeck theorizes that the rise in sea levels produced by Arctic warming and melting could have helped destabilize ice shelves at the edge of the Antarctic ice sheet and led to their collapse. If such a process occurred today, it would be accelerated by global-scale greenhouse-induced warming year round, Overpeck says. In the Arctic, melting would likely be hastened by pollution that darkens snow and enables it to absorb more sunlight.In the last few years sea level has begun rising more rapidly, now at a rate of about an inch per decade, says Overpeck. Recent studies have also found accelerated rates of glacial retreat along the margins of both the Greenland and West Antarctic ice sheets.