The Impact of Global Warming on Arctic Animals

Introduction

In 2000, a group of meteorologists concluded, on the basis of computer weather modeling, that there is less than 2 percent chance that the observed changes in sea ice across the entire Arctic could be the result of natural causes alone (Rizzuto 2001). For a long time, it had been debated how much of the warming trends being observed in the Arctic region are attributable to industrialization. But in the recent years there has been mounting evidence indicating that global warming is indeed happening for man-made reasons.

Global warming presents us with a scenario of gradually escalating crisis, which can eventually, and literally, sink our world — through the melting of polar ice caps. The arctic polar ice cap is melting and has thinned by over an astounding 45 percent in the last four decades (Jacobsen and Riebel 2002).

Global warming has already begun to devastate ecosystems, flora and fauna, biodiversity, in diverse regions all over the globe. The extremes of weather conditions that are at present causing havoc in the United States, Europe and elsewhere, and posing graver dangers in the future, are a direct consequence of global warming. However, since the effects of global warming are much more pronounced in the Arctic than in other parts of the world, its impact is much more direct and obvious there.

The Arctic is extremely vulnerable to the ongoing and predicted climate changes and its impacts. The reduction in sea ice is almost certain to have devastating impact on polar bears, ice-dependent seals, as well as the local populations for whom these animals are the primary source of food (Hassol and Corell 2006). The polar bear could very well be our canary in the coal mine. And this coal mine could prove to be a dark abyss that can spell the doom not only of countless species of plants and animals of our world, but ultimately humanity itself.

Climate Change in the Arctic

Global warming is a drastic climate change that is severely affecting the world’s oceans and countries across the globe. Global temperatures are slowly but steadily rising, largely owing to air pollution from the burning of fossil fuels. Global warming is caused by an increase in certain compounds, such as methane and carbon dioxide, which accumulate in the atmosphere. When fossil fuels burn, they emit these gases which trap the Sun’s heat, thus producing warmer weather.

The rising temperatures are warming the oceans, which makes the water expand and so raises sea levels. Sea ice is melting and now covers considerably less of the Arctic Ocean than it did thirty or forty years ago. Melting sea ice would affect the circulation of deep water currents and affect the temperature of warm surface currents, such as the Gulf Stream in the Atlantic (Houghton 2004).

One change would lead to another in a series of cascading chain events. These changes are expected to have dramatic effect on the climate of nations across the globe, and already are showing significant disturbing indications. There are also clear signs that, as the Arctic and Antarctic regions warm up, the land ice there, existing in the form of ice sheets and glaciers, is melting. This added water will cause sea levels around the world to rise sharply, and flood coastal areas (Tennesen 2004).

The Arctic is experiencing some of the most rapid and severe climate change on Earth. The impacts of climate change on the region and the globe are projected to increase substantially. The Arctic is really warming now. These areas provide a bellweather of what’s coming to planet Earth. — Robert Corell, Chairman of the International Arctic Science Committee that produced the Arctic Climate Impact Assessment (ACIA) report, November 2004. (Current Events 2004)

In November 2004, the Arctic Council, comprising the eight Arctic nations (Canada, Denmark, Iceland, Sweden, Nor-way, Finland, Russia, and the United States) released a landmark study on the effects of Global Warming on the Arctic environment, titled Arctic Climate Impact Assessment: Impacts of a Warming Arctic (ACIA). Emerging from the work of 300 scientists, the ACIA presents a very alarming situation that is a consequence of the present and expected global warming on Arctic ecosystems.

The climate is in fact changing at an accelerated pace in the Arctic region, as compared to the rest of the world. In the past few decades, temperatures in the Arctic have risen at nearly twice the rate as in the rest of the world. Some areas in the Arctic have warmed 10 times as fast as the world as a whole, which has warmed an average of 1 degree Fahrenheit over the past century.  In the past 50 years, average yearly temperatures in Alaska and Siberia have increased by about 16 degrees Fahrenheit, now hovering around minus 15 degrees Fahrenheit (Associated Press 2005).

For the whole Arctic, the ACIA projects additional warming of 7-13 degrees Fahrenheit, or 4–7°C, over the next century (Handwerk 2005). The impact of these climate changes is expected to aggravate drastically over the next century, contributing to major physical, ecological changes, many of which have already begun.

Because the world’s climate is warming up, the annual average amount of sea ice in the Arctic has decreased about 8 per cent in 30 years. Arctic summer sea ice is currently melting at an alarming rate of 9.2 percent per decade. According to scientific estimates, the waters of the Arctic could become ice-free for several months a year in less than a century (Associated Press 2005). This climate change will affect the people, wildlife, and environment of the Arctic Ocean in a much worse manner than air pollution, waste, overfishing, and oil exploration.

Animals Being Driven Towards Extinction

As sea melts, Arctic animals, such as the polar bear, will lose their habitat. Currently, about 20,000 to 30,000 of these animals exist, but as the ice-free period gets longer and longer, the window of time when polar bears can hunt for food would become shorter and shorter (Deshayes 2004).

Polar bears are entirely dependent on the ice platform for hunting and breeding. Eventually, the ice period is going to get too short for polar bears to get enough food, and that time does not seem to be far away at all, if the present global warming trends continue unabated. In the worst case scenario polar bears, walrus, some species of seal, and many other polar animals could be actually extinct within a few decades because of the effects of global warming (Klapper 2005).

This is very likely to have devastating consequences for some Arctic animal species … and for the local people for whom these animals are a primary food source. Should the Arctic Ocean become ice-free in summer, it is likely that polar bears and some seal species would be driven toward extinction. – the ACIA report (ACIA 2005)

Melting ice would mean that migratory birds, such as the arctic tern, are going to be deprived of breeding grounds in the Arctic, which would affect the biodiversity of all parts of the globe that such birds belong to. The breeding area for birds and grazing area for animals are going to continuously dwindle away so that many currently threatened species would become extinct and even those species that are in adequate numbers today would be driven to the verge of extinction. This is a seriously alarming prospect.

However, even if the current meltdown is not going to be such an ecological disaster which could spell the end of polar bears and many other Arctic animals, Arctic polar bear populations would definitely decline in alarming numbers in the coming 30 to 50 years. There is going to be a severe crisis situation for many other species dependent on the ice, such as the ringed seal, bearded seal and little auk.

More than half of the Arctic region is essentially ocean. Marine animals are particularly vulnerable to climate variations. Moreover, a significant proportion of all Arctic life forms rely either directly or indirectly on the bounty of the sea. Climate related changes could decimate sea-based life forms, and could indirectly have devastating effect on the birds and land animals which may subsist on the diet of these vanishing oceanic forms of life.

For example, it has been observed in 1987 in the Barents Sea that a climate-related collapse of capelin resulted in havoc for the many seabirds that breed in this area. The important point to note here is that the death or disappearance of one species may easily lead to the extinction of another species in the tightly-knit and delicately balanced ecology of the Arctic.

Impact of Global Warming on Individual Arctic Species

Species diversity is low in the Arctic, and decreases rapidly from the boreal forests to the polar deserts of the extreme north. Only about 3%, which translates 5900 species, of the world’s plant species occur in the Arctic, though some primitive plant species such as molasses and lichens appear in relative abundance.

The diversity of arctic animals is very similar to that of plants. Again, about 3% of the world’s animal species, which makes up about 6000 species, inhabit these ice-packed regions. Due to the extreme weather conditions, primitive species thrive in greater numbers than evolutionarily advanced species. Arctic animals are generally so well adapted to their environments that they generally tend to be slow to show any reaction to the heightened weather changes (ACIA 2005).

The Arctic has always experienced cycles of severe weather changes as part of a phenomenon known as Arctic Oscillation, and Arctic animals are remarkably adapted to withstand dramatic fluctuations in temperatures and all the associated climatic vicissitudes, especially the melting of ice. Nonetheless, the nature and degree of human-induced climatic changes currently underway in these northern extremes of the globe are presenting unprecedented challenges to the Arctic ecosystems (Cone 2005).

Species inhabiting northern regions are becoming particularly sensitive to global warming, while at the southern ranges many species are becoming susceptible to biological incursions of extraneous species. As the pace of global warming accelerates, forests will crop up in the southern parts of the Arctic, thereby pushing the frozen tundra landscape — and its wildlife of caribou, arctic fox, ptarmigan and insects — further north. Forested areas are spreading northward. In the Nordic regions, birch trees are taking over traditional reindeer lichen pastures, as a result of which the reindeer now have to compete with elk and red deer moving north.

A variety of species from Edith’s checkerspot butterflies to the red fox that generally live beyond the southern edges of Arctic have been gradually moving northward or to higher elevations, pushed on by warming temperatures in their traditional habitats. These shifts have sometimes caused no significant negative impact. But in other cases, they have made survival tougher as competing species come into contact with each other, for example, the competitively superior red fox is pushing the arctic fox farther towards the sea.

Polar Bears: Polar bears are at the top of marine food chain in the Arctic. One of the key findings of ACIA report is that the deleterious effects of pollution and contaminants in the diets of polar bears are compounded with the starvation caused by dwindling hunting grounds. Polar bears accumulate significant levels of toxic elements from eating ringed seals who have absorbed these chemicals by eating contaminated species lower in the food chain.

However, normally, the bears have the capacity to store such poisonous substance in their fat reserves and not let them affect their health. But due to the poor feeding seasons that are becoming a commonplace for these animals, their fat reserves are melting, thereby causing these toxins to be released into their bodies. Poor fat reserves in female polar bears also adversely influence their reproductive success. Further, lack of food would also imply lack of energy for these Arctic creatures to hunt successfully and feed their young. Thus, changes in ice extent and stability are militating against the very survival of polar bears as a species from many fronts.

Even if they are somehow able to survive the persisting present trend of later formation of sea ice in autumn and earlier break-up in spring, the polar bears are highly unlikely to outlast the complete loss of summer sea ice-cover which is expected to happen in less than hundred years. It is theoretically possible for these animals to radically change their summer life-styles and live as land-based animals for several months during a year, but practical considerations such as competition from other well adapted species and hunting down by man make their extended survival a very precarious proposition (ACIA 2005).

Caribou: Scientists believe that global warming will cause more ice storms in the Arctic. If that happens, prey animals will suffer. In 1961, scientists believed there were more than 24,000 Peary caribou in the Arctic. Today they think there are fewer than 2,000. It is thought that a bad ice storm in 1995 killed many caribou and musk oxen. If there are going to be many such instances of bad storms in the future, all the Arctic animals would be in serious trouble.

Caribou in certain regions of northwest Canada and Alaska are drowning as they cross rivers that normally are still ice when the animals migrate. Warming has also interfered with caribou feeding. Repeated freezing and thawing creates a crusty layer on the ground that makes it difficult for the caribou to reach the lichen on which they depend for their food (ACIA 2005).

Seals: Ringed seal, ribbon seal, and bearded seal, spotted seal, harp seal and such Arctic seal species lead a totally ice-dependent life style. Ringed seals are likely to be the most highly affected species of seal because all aspects of their lives, such as breeding, foraging, and shelter are tied to sea ice. Adapting to life on land in the absence of summer sea ice seems a very difficult likelihood for the ringed seal as they rarely, if ever, come onto land. Only a few seal species such as harbour seal and grey seal would be able to survive and expand their ranges in an Arctic that is becoming less and less covered with ice (ACIA 2005).

Seabirds: Certain species of birds are particularly liable to be negatively impacted by the thinning of sea ice. The ivory gull, for example, leads an existence that is intricately intertwined with sea ice, whether it is for the purposes of nesting or breeding or for shelter and protection. Serious declines have already been registered in ivory gull populations all over the Arctic, including an estimated 90% reduction in Canada over the past 20 years (ACIA 2005).

Walrus:  For walrus in many areas of the Arctic, the ice edge provides a optimal habitat for resting and feeding, because walrus eat clams and other shellfish on the continental shelves. However, as the ice edge retreats away from the shelves to deeper areas, clams would be hard to come by for the walrus. Also, disappearance of sea ice would imply that walrus may not be able to travel long distances on floating ice searching for feed over a wide area (ACIA 2005).

Conclusion

We have been able to examine the impact of global warming on the animal and bird species of the Arctic only at a cursory level. A deeper examination of the scenario presents us with much more complex and direr prospects. But the message that comes out of even a superficial investigation of the worsening environmental and ecological situation in the Arctic is clear: If we do not take drastic measures to reverse global warming trends soon enough, the situation is likely to go completely out of hand. All the nations of the world have to collectively take up a commitment to keep the global temperatures down by cutting down on their emission levels of greenhouse gases.

Failing which, we seriously jeopardize the very future of this planet. It is not just about plants, animals and birds anymore. The issue at stake here is not just biodiversity, or ecological health, or environmental safety etc, but the very survival of human race. Tomorrow the polar bear may become history, but the day after we humans may be relegated to the long list of extinct species.

References

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