How long has global warming affected the Arctic?

Answer 1

ever since people start use vast ammount of electricity global warming has gone up. This is when the polar bears started to be affected. If global warming goes up it means the ice caps start melting, and that means the polar bears have nowhere to go.

Hope this has helped

Answer 2

All the ice melts.......How are polar bears supposed to live... exactly...polar bears need ice to live because the only way they know how to live is with the ice and snow.

The evidence now shows the earth to be cooling..The ice packs are returning..Polar bear populations are stable or increasing slightly.

From a low of 800 only 100 years ago, we believe the number to now be over 25,000. No science group claims that global warming is affecting polar bears. Some reactionary groups seeking money claim that if global warming starts up again that someday it could affect polar bears and that you should give money now, just in case.

Answer 3

It is difficult to get an accurate count of polar bears, either before or after the recent rise in the earth's global warming. Estimates in the 1950s and 1960s came from native and other hunters, which were very local. The invention of the snowmobile and modern icebreakers meant that by the 1970s hunting of polar bears had reduced the population to about 10,000.

In 1973 hunting of polar bears was banned world-wide, except for native peoples, who had quotas set (this year's quota for all Canada is 500 bears). This partial ban on hunting led happily to an increase in bear numbers. Scientists now estimate the present population to be about 22,000 worldwide, of which 60% are in Canada.

There seems to be some decrease in numbers more recently, according to these reports in 2005 and 2009.

There are nineteen Polar Bear groups around the Arctic Circle. At the 2005 IUCN (International Union for the Conservation of Nature) Polar Bear Specialist group meeting, scientists reported that

• 5 of these groups of bears were declining in numbers,
• 5 groups were stable,
• 2 groups were increasing in numbers and
• 7 groups didn't have enough data to know.

The Report from the IUCN 2009 meeting found that

• 8 groups were declining in numbers,
• 3 groups were stable,
• 1 group was increasing in numbers and
• 7 groups didn't have enough data.

One of the best studied groups of bears, in Western Hudson Bay, in Canada. Bear population there has declined 22% in the past 17 years.

The bears there rely on the sea ice season to feed and build up their body reserves. When the sea ice melts earlier in summer (sea ice is now melting three weeks earlier than it did in 1990) the bears are forced onto land where there is limited food available. Longer summers mean the bears have to wait without food till the sea ice returns. The average weight of female bears is declining and with it their chance to have strong and healthy cubs.

Answer 4

Some of the sea rise over the twentieth century is undoubtedly from melting of the polar ice caps, although no detailed studies were made until later in the century.

Experts apparently agree that the age of the perennial sea ice cover exceeds 700,000 years but disagree about how much older it is. However, a clear trend to melting of the sea ice is apparent in the late 1990s and especially in the present century.

The tundra permafrost has also begun to experience changes in the last few years. A study by National Snow and Ice Data Center with conservative assumptions has concluded, "Thawing permafrost feedback will turn Arctic from carbon sink to source in the 2020s, releasing 100 billion tons of carbon by 2100."