By Malee Oot
In the midst of the planet’s sixth mass extinction, species worldwide are disappearing at an alarming rate – and climate change will only exacerbate the situation. Unlike extinctions of the past, which resulted from natural phenomena like asteroids and volcanoes, this one is triggered entirely by humans, driven by factors habitat destruction, the introduction of invasive species, and climate change. A significant portion of the earth’s imperiled species are already being impacted by rising temperatures — and without intervention, the outlook could be bleak. According to a study published in the journal Nature Climate Change earlier in 2017, climate change is already affecting almost half of the world’s endangered mammals, and nearly a quarter of the endangered birds on the planet – a total of more than 700 threatened and endangered species. From the land fast ice along the Arctic coast to the rainforests of Australia, wildlife all over the world are feeling the impacts of rising temperatures.
Living primarily above tree line in mountain ranges spread over a dozen countries in northern and central Asia, snow leopards are notoriously elusive. Dwelling at elevations of 3,000 to 5,000 meters, the sturdy cats are engineered to deftly navigate rugged terrain and thrive in alpine extremes — even able to survive temperatures as low as -40 degrees Celsius. Yet, despite their uncanny capacity to tolerate inhospitable conditions, climate change presents several compounding challenges for snow leopards, cats already vulnerable to extinction. According to a study published in the journal Biological Conservation last year, climate change could render 65% of the cat’s current range unsuitable by 2070 – with alpine ecosystems in the Hengduan and Himalayan mountains being the most vulnerable. Factors like rising temperatures, heavier rainfall, and shifts in vegetation will also affect the prevalence of the bovid species the cats prey on – namely Blue sheep, Asiatic ibex, and argali. Based on the climate scenarios utilized in the study, rising temperatures mean Himalayan countries could lose significant portions of their viable snow leopard habitat – with as much as 82% disappearing in Nepal, and 84% in Bhutan. At the same time, warmer temperatures will continue to push human settlement to higher elevations, further reducing space available for the far-roaming cats. Dwindling prey and continually encroaching human populations can also drive snow leopards to target livestock – acts of desperation which can incite retaliatory killings.
Something like a cross between a rabbit, a chipmunk, and a prairie dog, the American pika inhabits the rock-strewn slopes of mountain ranges throughout the American west, from the Rockies to the Sierras. The hearty herbivores can survive frigid alpine conditions, but warmer temperatures could put pikas in peril – especially because temperatures above 25.5 degrees Celsius can kill the pint-sized mammals. The craggy, talus slopes inhabited by American pika are experiencing hotter, drier summers and are becoming more inhospitable in the winter, with less snowpack to provide a heat-trapping buffer. The IUCN Red List currently classifies the American pika as a species of Least Concern, but a study conducted by the United States Geological Survey from 2012 t0 2015 found the animals have disappeared from significant portions of their range in northeastern California, southern Utah, and the Great Basin, which stretches from Utah’s Wasatch Mountains to the Sierra Nevada. Pikas have already vanished completely from Zion National Park, and have disappeared from most of their former turf in Cedar Breaks National Monument in Utah. Environmental organizations like the Center for Biological Diversity have pushed for the American pika to be added to the endangered species list, but so far the U.S. Fish and Wildlife Service has denied protection for the animals in both 2010 and 2016.
Poaching has already put Africa’s elephants in a perilous position, especially in Central Africa, but demand for ivory is just one the challenges facing the largest land mammal on the planet. Habitat loss combined with increasing pressure on natural resources present escalating conservation challenges for the species — and will only be exacerbated by climate change. Throughout sub-Saharan Africa – the continental range of African elephants– climate change is projected to bring warmer temperatures and more frequent heat extremes, particularly during the summer. At the same time, rainfall patterns are expected to become increasingly unpredictable. Many of these impacts have already manifest across the continent – with devastating impacts for both humans and wildlife. Over the last decade, droughts have become almost an annual occurrence in sub-Saharan Africa. In 2011, the worst drought to hit the region in more than 60 years impacted over 12 million people – and today, the countries of the Horn of Africa continue to grapple with a prolonged drought that has stretched on for more than three years and affected nearly 22.9 million people. Diminished rainfall is also disastrous for regional wildlife, especially elephants – the pachyderms require up to 300 litres of water a day. In 2009, after three rainy seasons failed to produce, 40% of the grazing mammals in Kenya’s Tsavo West National Park perished, according to the International Fund for Animal Welfare. Droughts and other extreme weather events across sub-Saharan Africa have also caused increases in incidences of human-wildlife conflict, as competition for fast-dwindling resources — like water – intensifies. Another issue for elephants coping with climate change is their reproduction process. The animals have a gestation period of about 22 months – the longest of all mammals – and females typically only have a calf every 4 to 6 years, meaning populations can be slow to recover from extreme weather events. Elephant reproduction is tied to rainfall in more subtle ways too. Phases of peak birth coincide with the heaviest periods of rainfall, meaning that droughts also profoundly alter elephant reproduction cycles.
Universally adored for their endearingly cartoonish appearance, koalas are quite possibly Australia’s most iconic species – but the globally beloved marsupial could be in serious peril. With waterproof pelts coveted as lining for hats, gloves and coats, the arboreal mammals were nearly hunted to extinction in the early part of the 19th century – until public outrage ultimately halted the trade in koala fur in the 1930s. Today, the eucalyptus-noshing marsupials face a host of other risks, including diseases like the koala retrovirus and threats from sprawling human development, along with hotter, drier conditions and violently destructive bushfires driven by climate change. According to the Australian Koala Foundation, nearly 80% of forests utilized by the arboreal marsupials have been cleared since 1788, and in the next half-century, climate change could also render much of the koala’s remaining habitat inhospitable, according to a study published in the journal Global Change Biology last year, based on research undertaken by the University of Melbourne. Although exceptionally well adapted to Australia’s dry climate, according to the study, as climate change continues to bring hotter temperatures and decreased precipitation across the koala’s range, the animals will no longer be satiated by their primary food source – eucalyptus. Believed to be named for an aboriginal phrase meaning ‘no drink,’ koalas get their water from moisture stored in the nearly two and a half pounds of eucalyptus leaves they consume daily. But, warmer weather and less rainfall mean drier eucalyptus leaves – making koalas water-deprived, and susceptible to fatal heat-stress. Even in Gunnedah, dubbed the ‘Koala Capital of the World,’ climate change is driving the tree-borne marsupials to alter their behaviour. In March, researchers from the University of Sydney observed even during the winter, extreme thirst was driving local koalas to uncharacteristically descend from the treetops to drink from artificial water stations, both day and night.
Polar bears might be the poster child for climate change in the Arctic, but disappearing sea ice also spells disaster for several other species – including ringed seals. The smallest and most widely distributed seal in the Arctic, the blubbery pinnipeds rarely venture onto solid land, using sea ice throughout the year for breeding, calving, moulting, and just hanging out. The species is also the most ice-adapted seal in the Arctic, even able to create breathing holes in the sea ice using specialized claws on their fore-flippers. However, climate change is rendering the ringed seal’s ice-savvy adaptations useless. The Arctic continues to warm twice as fast as the rest of the world, and sea ice is disappearing at an alarming rate. According to some models, Arctic summers could be ice-free as soon as 2020 – a scenario which would be disastrous for ringed seals. But, the disappearance of the seals would also be catastrophic for polar bears, the pinniped’s primary predator. In the Svalbard region of Norway, researchers from the Norwegian Polar Institute and the Arctic University of Norway found that during summers with less sea ice coverage, area polar bears were unable to hunt ringed seals, and instead turned to nesting birds – ultimately, a source of prey without enough caloric content to sustain the Arctic-dwelling bruins.