Polar bears’ primary habitat is sea ice they use that platform to hunt seals, their main food source. The International Union for the Conservation of Nature (IUCN) publishes a “Red List” – an overview of the conservation status of threatened animal and plant species. The latest iteration, published in 2015, classifies polar bears as “vulnerable”, meaning they are facing a high risk of extinction in the wild. The reason they have a high rate of extinction is because the level temperatures in the Arctic are rising at least twice as fast as the global average causing sea ice cover to diminish by nearly four per cent per decade. According to the carbonBrief the loss of sea ice affects polar bears’ ability to find food, studies show. Polar bears feed on ringed seals that live at the ice edge; the seals provide two thirds of the energy polar bears need for the entire year in late spring and early summer. With the ice retreating earlier in spring and forming later in winter, the bears have less time to hunt prey and have to go without food for longer. But why would we care if the polar bear becomes extinct? It turns out if polar bears start to disappear the seal population would increase rapidly because they are currently the main prey for polar bears. If the seal population increased then fish populations would decrease at an alarming rate because seal prey on fish. This would lead to a shortage of fish. And some of the countries already expiring this shortage are the Maldives, South Korea, Japan, Iceland and many more.
However the biggest impact of melting ice because of climate change is rising of sea level. According to National Ocean Service with the majority of Americans living in coastal states, rising water levels can have potentially large impacts. Scientists have determined that global sea level has been steadily rising since 1900 at a rate of at least 0.04 to 0.1 inches per year. Sea level can rise by two different mechanisms with respect to climate change. First, as the oceans warm due to an increasing global temperature, seawater expands taking up more space in the ocean basin and causing a rise in water level. The second mechanism is the melting of ice over land, which then adds water to the ocean. According to National Geographic there are multiple climate change factors that contribute to the rising sea level is such thermal expansion; that’s when water heats up and it expands. About half of the sea-level rise over the past 25 years is attributable to warmer oceans simply occupying more space. Another factor is melting glaciers. As summer comes large ice formations such as mountain glaciers naturally melt a bit. In the winter, snows, primarily from evaporated seawater, are generally sufficient to balance out the melting. Recently, though, persistently higher temperatures caused by global warming have led to greater-than-average summer melting as well as diminished snowfall due to later winters and earlier springs. That creates an imbalance between runoff and ocean evaporation, causing sea levels to rise. As these ice caps are melting sea levels rise as rapidly as they have been, even a small increase can have devastating effects on coastal habitats farther inland; it can cause destructive erosion, wetland flooding, aquifer and agricultural soil contamination with salt, and lost habitat for fish, birds, and plants.
https://oceanservice.noaa.gov/facts/sealevelclimate.html
As a result flooding occurs and in low-lying coastal areas is forcing people to migrate to higher ground, and millions more are vulnerable from flood risk and other climate change effects. Most predictions say the warming of the planet will continue and is likely to accelerate, causing the oceans to keep rising. This means hundreds of coastal cities face more flooding. If we don’t stop our planet from warming it not only is going to lead to extinction of polar bears, but it might lead to extinction of human habitats as well.
References
https://oceanservice.noaa.gov/facts/sealevelclimate.html
https://www.carbonbrief.org/polar-bears-and-climate-change-what-does-the-science-say
https://www.nationalgeographic.com/environment/global-warming/sea-level-rise/#close
