The Effects Of Climate Change On Polar Bears – Polar bears could become virtually extinct by the end of the century as a result of shrinking Arctic sea ice if global warming is not halted, scientists said Monday.

From the Beaufort Sea off the coast of Alaska to the Siberian Arctic, nearly all of the 19 polar bear subpopulations will disappear as the loss of sea ice forces the animals onto land and away from their food for longer periods of time, scientists predict. said. Prolonged fasting and reduction in maternal breastfeeding results in rapid declines in offspring and survival.

The Effects Of Climate Change On Polar Bears

The Effects Of Climate Change On Polar Bears

“If greenhouse gas emissions continue at so-called business-as-usual levels, polar bears have little chance of surviving anywhere in the world except in the very high Arctic,” said Peter K. Molnar. , a researcher at the University of Toronto Scarborough and lead author of a study published Monday in the journal Nature Climate Change.

Species Hit Hard By Climate Change—including One That’s Already Extinct

Dr. Molnar said that even if emissions were reduced to moderate levels, “unfortunately, we would still lose some, especially some of the southern population, from the loss of sea ice.”

The fate of polar bears has long been a focus of debate over human-caused climate change, used by scientists and environmentalists as well as deniers in their arguments.

According to estimates, there are about 25,000 polar bears in the Arctic. Their primary habitat is sea ice, where they hunt for seals by waiting for them to surface through holes in the ice. In some areas, bears remain on the ice year-round, while in others, spring and summer thaws force them ashore.

“You need sea ice to get your food,” Dr. Molnar said. “There isn’t enough food on land to sustain polar bear populations.” But bears can fast for months at a time, subsisting on fat energy stored on a seal diet.

Five Surprising Effects Of Arctic Climate Change

Arctic sea ice grows in winter and melts and retreats in spring and summer. As the region has warmed rapidly in recent decades, summer sea ice has decreased by about 13 percent each decade compared to the 1981-2010 average. Some parts of the Arctic, which used to have ice all year round, now experience ice-free periods in the summer. Other parts are ice-free for a longer part of the year than before.

Dr. Molnar and his colleagues looked at 13 subpopulations that make up 80 percent of the total bear population. They calculated the energy needs of the bears and determined how long they could live on a fast, or, in the case of females, survive and nurse their cubs.

Combining this with climate model projections of ice-free days up to 2100, they found that if current rates of warming continue, for almost all subgroups, animals’ fasting times will eventually exceed their holding times. capable of fasting.

The Effects Of Climate Change On Polar Bears

Complicating the problem is that the duration of fasting also means periods of less eating. “Not only do bears need more energy to fast, they need more energy to get through it, and it’s harder to store that energy,” he said.

Polar Bears Affected By Climate Change

During fasting, bears move as little as possible to conserve energy. But the loss of sea ice and population declines create new challenges — for example, more energy spent searching for mates — that could further affect survival.

The study found that even under slightly warmer projections, with greenhouse gas emissions peaking by 2040 and then beginning to decline, many subgroups would still disappear.

Over the years, the polar bear has become a symbol, both for those who call for urgent action on global warming and for those who argue that climate change is not happening, and at best, that the problem has gone too far.

Groups including the Cato Institute, a libertarian research organization that disputes aspects of climate change, have called concerns about bears unfounded, saying some studies show the animals have repeatedly survived warmer periods. But scientists say that in earlier warm periods, bears, especially whales, had important alternative food sources that are missing today.

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Images of bears walking on isolated ice floes or foraging for food have been used by conservation groups and others to highlight the need for action to reduce warming. But sometimes it turns out that these pictures are not what they seem.

In 2017, after a video of an emaciated bear scavenging in the Canadian Arctic was published online by National Geographic, the magazine admitted that the bear’s plight may not be related to climate change. Scientists point out that there is no way of knowing what happened to the bear; May be sick or very old.

Cecilia M., an atmospheric scientist at the University of Washington and the author of the study. The researchers needed to be able to determine as precisely as possible when the sea ice would disappear from a particular area. “If we wanted to look at a lot of models, we wouldn’t be able to do that,” Dr. Bitz said.

The Effects Of Climate Change On Polar Bears

Andrew Derocher, a polar bear researcher at the University of Alberta who was not involved in the study, said the findings from wildlife observations, for example, “are very consistent with what we’re seeing.” “The study clearly shows that polar bears do better with less heat,” he added. “But whichever scenario you look at, there are serious concerns for the conservation of the species.”

How Climate Change Is Upending The Arctic Food Web

Of the 19 subpopulations, little is known about some of them, particularly those in the Russian Arctic. Of the subpopulations studied, some – usually in areas with less ice loss – have so far shown population declines. But others, particularly the southern Beaufort Sea in northeastern Alaska and Hudson Bay in western Canada, have been hit hard by sea ice loss.

One analysis shows that the southern Beaufort Sea subpopulation declined by 40 percent in the first decade of this century, to about 900 bears.

One drawback of such studies, Dr. Derocher said, is that while they can show long-term trends, “it becomes very difficult to model what’s going on from year to year.”

Polar bear populations can be very sensitive to sudden changes in conditions, he said. “One of the big problems in conservation is that one or two bad years can take a healthy population and push it really low.”

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Henry Fountain specializes in the science of climate change and its impacts. He has written about science for The Times for more than 20 years and traveled to the Arctic and Antarctic. More about Henry Fountain

An editorial version of this article appears in the New York edition on page 12 with the headline: Climate change, climate change will hurt polar bears, and be blamed for the limited, future. Order Reprint | Today’s paper | Polar bears face a bleak future due to the effects of climate change, and the loss of their habitat and food supply is putting their lives at risk.

Polar bears are one of the most iconic species on the planet, but they face a dire future due to climate change. These magnificent animals have adapted to life in the Arctic and depend on sea ice for hunting and travel. However, due to rising global temperatures, sea ice is rapidly melting, and polar bears are losing habitat and food sources.

The Effects Of Climate Change On Polar Bears

According to the United States Geological Survey (USGS), the Arctic will warm twice as fast as the rest of the world, causing sea ice to shrink by 13% in ten years. This loss of sea ice has a direct impact on polar bears’ hunting and mating habits, as they rely on the ice to reach their prey. When the sea ice retreats during the summer months, polar bears are forced to swim long distances in search of food, resulting in less energy and less food. In some areas, polar bears have been observed foraging in populated areas, increasing the risk of human-bear conflict.

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Climate change is also harming the food supply chain in the Arctic, reducing food supplies for polar bears. With the warming of the Arctic Ocean, phytoplankton and zooplankton, which are the building blocks of the food chain, will decrease. This, in turn, affects populations of large species that are primary prey for polar bears, such as seal populations. A decrease in food supply leads to increased competition between the polar bear and other arctic predators such as the Arctic fox, and a decline in the overall polar bear population.

The main cause of climate change is the release of greenhouse gases into the atmosphere. A significant contributor to these emissions is industrial livestock farming, or “factory farming.” According to the report of the Food and Agriculture Organization of the United Nations

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