Photo: ?
Polar bear mother and cub
on the sea ice – Baffin Bay.
Photo: Peter Van Wagner/iStock
Rhone glacier in Switzerland.
Photo: Konrad Steffen
of course, also the potential for the sea level to continue people in Asia (Himalayan region) and in Europe (The
to rise a great deal more. If all the ice masses on land Alps) and the Americas (Andes and Rocky Mountains)
melted the sea level could eventually rise by around 65 depend on river systems with glaciers inside their catch-
metres
3
. This is virtually unthinkable, since the average ment areas. In areas where the glaciers are melting, river
temperature on Antarctica, where most of this ice is lo- runoff will increase for a period before a sharp decline
cated, is now about –30 ºC to –40 ºC. But even a minor in runoff. Without the water from mountain glaciers, se-
melting of these ice masses would have significant con- rious problems are inevitable and the UN’s Millennium
sequences. For example, if the ice melts by 20 per cent Development Goals for fighting poverty and improving
in Greenland and 5 per cent in Antarctica at the same access to clean water will be jeopardized.
time, the sea level will rise by 4 to 5 metres. This will
have not only major consequences for the small islands The ecosystems and biological diversity in polar and
in the Pacific, Caribbean, and the Indian Ocean, but also mountain regions will change significantly in a warming
for countries like the Netherlands and Bangladesh; and world. The zone along the edge of the sea ice is bursting
cities and coastal infrastructure in many other countries with life despite what at first glance appears to us to be
will be affected negatively. one of the most hostile environments on the Earth. Both
the underside and the top surface of pack ice, as well as
With few exceptions, all the alpine glaciers of the world openings in the ice, are home to myriad marine plants
are losing mass and it is predicted that this trend will con- and animals – from long strands of algae under the ice
tinue as global warming progresses
5
. Glaciers in alpine ar- and innumerable small crustaceans, to seals, marine
eas act as buffers. During the rainy season, water is stored birds, and polar bears (Chapter 5). The ice-edge zone is a
in the glaciers and the melt water helps maintain river biological oasis in the spring and summer when the sun
systems during dry periods. An estimated 1.5 to 2 billion shines around the clock
2
. Many species are specifically
24 GLOBAL OUTLOOK FOR ICE AND SNOW