Specialisation: Polar Bears

The Consequences of Climate Change


Climate change poses an ominous threat to the delicate ecosystems that intricately sustain life on our planet. The region most affected by climate change is the Arctic, a sprawling expanse of ice and frigid waters home to a unique tapestry of life. The Arctic is currently undergoing unprecedented transformations, its essence reshaped by surging temperatures and the rapid melt of once-enduring ice caps due to its icy and pristine landscape. Within this rapidly evolving Arctic tableau, Polar bears and narwhals grapple with the existential challenge of adapting to an increasingly inhospitable environment. Both species, once finely tuned to the harsh rhythms of the Arctic, now confront the alarming reality of disruptive alterations to their habitats. The intricate balance that sustained them is unraveling as the familiar stability of their surroundings gives way to the uncertainties wrought by climate change. As temperatures soar, the ice platforms crucial to the survival of Polar bears and narwhals are dwindling at an alarming rate. This reduction initiates a domino effect, extending beyond the immediate concerns of their survival.

Thesis statement: Climate change is jeopardizing the existence of Polar bears and narwhals by altering their habitats and disrupting their food supply.


Polar bears face a formidable challenge as climate change reshapes their Arctic habitat. According to Hamilton and Derocher, “climate change has become the primary threat manifesting as a loss of sea ice habitat and due to extensive research and long-term monitoring in some regions, polar bears have emerged as an iconic species for the effects of climate change” (83). Their critical reliance on sea ice, a fundamental platform for hunting their primary prey, seals, makes them more affected by climate change. However, the Arctic’s alarming warming trend is causing a rapid ice retreat, transforming the bears’ hunting grounds into expanses of open water. As the ice diminishes, Polar bears are compelled to embark on perilous journeys, covering greater distances in search of suitable hunting grounds. This extended travel exacts a toll on the bears’ energy reserves, leading to a concerning pattern of energy depletion. The repercussions are profound, manifesting in diminished body condition and, consequently, a decline in reproductive success, “Declining body condition and reproduction are amongst the first subpopulation-level effects to occur in polar bears as a result of habitat loss due to climate change” (Laidre et al., p.13). The reproductive cycle of these apex predators is disrupted, with potential long-term implications for the overall population dynamics. Moreover, the decline in sea ice necessitates increased travel and curtails Polar bears’ access to seals, their primary prey. Seals rely on the ice as a platform for breeding and resting, and with its diminishing extent, their habitats are compromised. This reduction in suitable hunting grounds intensifies the competition among Polar bears for limited resources, exacerbating the challenges they face in securing sufficient food. The resultant escalation in intra-species competition poses a multifaceted threat to the Polar bear population, further compounding the adverse effects of climate change on these majestic creatures.

Some other arctic animals hugely affected by climate change are Narwhals. According to Chambault et al., “Narwhals are generally considered to be among the most sensitive and vulnerable of Arctic endemic marine mammals to climate changes15 due to their choice of habitat, limited prey selection, strict migratory patterns, and high site fidelity” (6). These animals embody a distinctive and enchanting presence in the Arctic’s icy waters. Yet, their essence is under siege as climate change transforms the environment where they spend their lives. Uniquely adapted to the frigid Arctic waters, narwhals encounter profound challenges as the region undergoes warming trends, disrupting the delicate balance of their ecosystem. The complex balance of life in the Arctic revolves around the availability and distribution of prey species, which climate change is destabilizing for narwhals. The warming of Arctic waters directly influences the distribution of their prey, creating a ripple effect that echoes through the narwhals’ entire way of life. Migration patterns, often associated with the availability of the ice, are ruffled, leaving Narwhals to navigate an environment that is increasingly unpredictable. The reduction in sea ice has both advantages and disadvantages for the lives of the narwhals. While the decline hampers their ability to navigate through once-frozen channels, it also exposes them to heightened risks from predators. The loss of protective ice cover diminishes their natural defenses, increasing vulnerability to threats from natural predators and potential human interactions. Changes in ocean temperature and acidity also disrupt the availability of prey for narwhals, further amplifying the struggle for survival. The delicate balance that sustained their populations is now in jeopardy, impacting not only individual narwhals but also the broader health of their entire species. As the challenges mount, from disrupted migration patterns to increased vulnerability, the fabric of narwhal existence is unraveling in the face of climate change.

The intricate repercussions of climate change on Polar bears extend beyond the direct impact on the bears themselves, delving into the heart of their food supply and hunting dynamics. The substantial decline in sea ice, a consequence of escalating Arctic temperatures, initiates a transformative shift in the accessibility and availability of seals, their primary prey. While Polar bears are renowned for their predation on ringed and bearded seals, the intricate web of climate-induced changes also ripples through the distribution and abundance of harp, hooded, and ribbon seals, contingent on their geographic location. According to Reimer et al., “Polar bears prey heavily on ringed seal pups, so in years with low ringed-seal productivity, bears may be forced to change either the composition of their diet, reduce their energy intake, or both” (141). As the ice platforms become unstable, Polar bears find themselves compelled to adapt their hunting strategies to the shifting dynamics of their Arctic environment. The diminishing ice cover disrupts the seals’ breeding and resting grounds and triggers a cascading effect on the availability of alternative food sources for the bears. This transformative landscape presents Polar bears with the challenge of navigating the changing Arctic in pursuit of prey undergoing its adaptation to the warming climate. Consequently, the result is a heightened struggle for sustenance among Polar bears as they contend with the dual challenges of reduced ice cover and the evolving distribution of seals. The intensified competition for limited resources increases the likelihood of conflicts among individual bears, posing threats not only to personal survival but also to Polar bear populations’ broader health and dynamics.

Similarly, narwhals navigate a shifting and increasingly precarious Arctic landscape shaped by the disruptive forces of climate change. The alterations in sea ice and ocean conditions, stemming from the global rise in temperatures, reverberate through the delicate intricacies of the narwhals’ food supply. Unlike the terrestrial realm of Polar bears, narwhals primarily rely on the ocean’s bounty, relying on fish and squid for their diet. As climate change disrupts the patterns of sea ice, altering ocean temperatures and dynamics, the distribution and abundance of crucial prey species for narwhals undergo profound changes, “many polar marine predators are being negatively affected by global warming, which is decreasing the availability of habitat and prey” (Louis et al., p.7). Their sources of sustenance, including fish and squid, experience shifts in their geographical ranges and availability, forcing narwhals to adapt to a transformed seascape. These alterations in prey populations upset the delicate balance that sustains narwhals and their intricate ecosystem. The consequences extend beyond the individual narwhals to influence the broader Arctic food web and ecosystem dynamics. The interconnectedness of species in the Arctic means that disruptions to narwhals’ food supply have cascading effects on other marine life, potentially destabilizing the fragile equilibrium of the entire ecosystem. As narwhals grapple with the challenges of finding and securing their essential prey, the repercussions extend to their reproductive success, overall health, and population dynamics.


The effects of climate change on Polar bears and narwhals are profound and interconnected, extending beyond immediate threats to these arctic species. The diminishing sea ice, a consequence of escalating temperatures, disrupts Polar bears’ habitats and the distribution of their primary prey, creating complex challenges. Similarly, narwhals face a shifting seascape as alterations in sea ice and ocean conditions impact the availability of vital prey species. The consequences of these disruptions reach far beyond individual bears and narwhals, influencing the broader Arctic food web and ecosystem dynamics. The delicate balance sustaining these species and their environment is under threat, emphasizing the urgency of global action to mitigate climate change’s impacts. Urgent measures are required to ensure the continuity of this unique biodiversity, safeguarding the intricate life that defines the Arctic. Through collaborative efforts and a commitment to sustainable practices, there is an opportunity to mitigate the effects of climate change and preserve the Arctic’s lives for present and future generations.

Works Cited

Chambault, P., et al. “The impact of rising sea temperatures on an Arctic top predator, the narwhal.” Scientific Reports, vol. 10, no. 1, 2020, https://doi.org/10.1038/s41598-020-75658-6.

Hamilton, S. G., and A. E. Derocher. “Assessment of Global Polar Bear Abundance and vulnerability.” Animal Conservation, vol. 22, no. 1, 2018, pp. 83–95, https://doi.org/10.1111/acv.12439.

Laidre, Kristin L., et al. “Interrelated ecological impacts of climate change on an apex predator.” Ecological Applications, vol. 30, no. 4, 2020, https://doi.org/10.1002/eap.2071.

Louis, Marie, et al. “Influence of past climate change on phylogeography and demographic history of narwhals, monodon monoceros.” Proceedings of the Royal Society B: Biological Sciences, vol. 287, no. 1925, 2020, p. 20192964, https://doi.org/10.1098/rspb.2019.2964.

Reimer, Jody R., et al. “Evidence of intraspecific prey switching: Stage-structured predation of polar bears on ringed seals.” Oecologia, vol. 189, no. 1, 2018, pp. 133–148, https://doi.org/10.1007/s00442-018-4297-x.