Global warming, a scientifically documented phenomenon wherein the global temperature is steadily rising, has a profound impact on species all over the world. Polar bears and other Arctic species are particularly at risk because their habitat is increasingly threatened by the rising temperatures. Numerous scientific agencies have shown that polar bear numbers are on the decline, and that if action is not taken quickly, these animals may vanish from the Earth, deprived of habitat, food, and shelter.
In the wild, polar bears spend much of their lives wandering pack ice in search of food, which presents itself in the form of other Arctic animals like seals. These bears have adapted to a high fat diet from ocean-going animals like seals: they are rapid and aggressive swimmers, allowing them to readily capture their prey. Each summer, as the pack ice starts to shrink, polar bears draw closer to land to give birth to and nurse cubs. Many forgo food during this period, hunting again when the ice returns and living on stored fat.
Pack ice overall is decreasing globally. When it does form, it melts more quickly, and tends to be thinner as well. In 2004, several polar bear deaths by drowning were recorded, something which was unheard of before. The bears had been trapped on isolated areas of floating ice, and had tried to swim for land. Due to the shrinkage of the ice, they tired and drowned before reaching shore and safety. This problem is likely to grow as the pack ice shrinks.
The shrinkage of the ice has other repercussions for polar bears: they are losing their natural prey, who are also affected by the shrinkage in habitat. The bears are not very adept at catching land animals such as caribou, and also must contend with other species for these food sources. Land animals also do not provide the high fat diet that polar bears need, which may lead to starvation. Starving mothers may not be able to provide their cubs with the nutrition they need, which will further contribute to the decline in polar bear numbers.
While searching for food and habitat, polar bears have also clashed with humans. Interactions with the animals used to be very rare, because the bears kept to the sea ice. With the disappearance of that ice, bears have begun to show up around inhabited areas looking for food and shelter. They contend with hunters for their kills and often end up being slaughtered because they pose a threat to human communities.
The combination of deadly factors brought about by global warming put polar bears at a very high rate of risk. Drops in birth and survival rates have already been documented, and biologists are growing concerned about erratic behavior exhibited by the animals as a result of the loss of their natural habitat. Organizations dedicated to the welfare of the environment believe that a global effort is needed to counteract global warming before it is too late for polar bears, as well as many other species that call Earth home.