Sentences with phrase «polar bear population by»

Projections in 2007 indicated that by the middle of the century loss of Arctic ice will have reduced the 22,000 polar bear population by two - thirds.

Recent estimates suggest a 60 % reduction of the polar bear population by the year 2050.

Not exact matches

A comprehensive review (pdf) by the US Fish and Wildlife Service concluded that shrinking sea ice is the primary cause for the decline seen in these populations, and it recently proposed listing polar bears as threatened (pdf) under the Endangered Species Act.

So how to explain the increase in the polar bear population from 5,000 in 1950 to 25,000 today, as documented by the U.S. Fish & Wildlife Service?

Steven C. Amstrup, the federal biologist who led an analysis last year concluding that the world's polar bear population could shrink two thirds by 2050 under moderate projections for retreating summer sea ice, is once again in the field along Alaska's Arctic coast, studying this year's brood of cubs, yearlings and mothers.

I do not want to draw any conclusions as to the threat to the polar bear populations posed by the ongoing environmental changes / future warming of the Arctic.

RE - Sanjong Thanpa: «So how to explain the increase in the polar bear population from 5,000 in 1950 to 25,000 today, as documented by the U.S. Fish & Wildlife Service?»

how to explain the increase in the polar bear population from 5,000 in 1950 to 25,000 today, as documented by the U.S. Fish & Wildlife Service?

Regardless of whether hybridization rates may increase, at least for polar bears any effect they might have on population welfare pale by comparison to the loss of habitat and subsequent loss of foraging ability.

Models created by experts said such a dramatic loss of sea ice would cause a sharp drop in the polar bear population and threaten their very survival.

The International Conservation Union, in its latest red list of endangered wildlife, gave polar bears threatened status in May, projecting a decline of 30 percent by midcentury from current populations, mainly due to projected losses of sea ice in a warming world.

By the time a child born in 2015 retires around 2090, she'll be living in a world with few wild polar bears or Arctic populations of narwhals, bearded seals, and ringed seals.

Taylor also debunked the notion that less sea ice means less polar bears by pointing out that southern regions of the bears» home with low levels of ice are seeing booming bear populations.

In news that may be shocking to ClimateDepot, polar bear population is affected by non-climatological factors such as regulations on polar bear hunting, just like India's population is affected non-AIDS factors such as vaccination programs.

Based on such studies Dr. Derocher, chairman of the IUCN's Polar Bear Specialist Group (PBSG) warned, «It's clear from the research that's been done by myself and colleagues around the world that we're projecting that, by the middle of this century, two - thirds of the polar bears will be gone from their current populations».

The BioScience study also analyzed the arguments made by 45 science - based blogs about the impacts of global warming on polar bear populations.

One by The Guardian's George Monbiot discusses Ridley's claim that «11 of 13 populations» of polar bears are «growing or steady.»

Therefore, due to entirely natural variations in spring snow conditions over sea ice (and thickness of the ice), 2 polar bear population sizes can vary by region.

This natural variation in population size is seldom mentioned by those who rush to blame all polar bear subpopulation declines on recent increases in the open water season.

This too is understandable as Derocher was invested in his earlier predictions that «by the middle of this century, two - thirds of the polar bears will be gone from their current populations»

If that occurs, the premature removal of protection offered by subnivean birth lairs may expose young ringed seal pups to high levels of predation, which may negatively affect populations of ringed seals and the polar bears that depend on them for food.

Watch the global warming issue zooming by in a superficial manner and all the horrific claims — increasingly extreme weather events, imperiled polar bear populations, skeptics who are paid to lie about the truth of all of this — sound like they are true.

If polar bears are endangered by global warming, why have bear populations more than doubled in the last 50 years?

Susan Crockford is a polar bear expert with a message that climate alarmists don't want to hear: polar bear populations are thriving and are certainly in no danger from thinning summer sea ice supposedly caused by «man - made global warming.»

Animal populations decline for all sorts of reasons, and in the case of polar bears, being hunted by people is certainly one cause for concern.

Large margins of error in polar bear population estimates means the conservation status threshold of a 30 % decline (real or predicted) used by the US Endangered Species Act and the IUCN Red List is probably not valid for this species.

They provided alternate explanations for the decline of polar bear populations, such as stress from interactions with tourists, and suggested the bears could adapt to a warming climate by supplementing their diet with berries and vegetation.

The polar bears of western Hudson Bay are on the front line of global warming impacts: their population declined by 22 percent between 1987 and 2004 and may be the first driven extinct by climate change.

Wilder presents these numbers as a basis for saying how concerned he is that a longer open - water season in the Arctic could increase the number of attacks by polar bears — and he's right, that's a valid concern now that the global population of bears is so high.