Wildlife We could Lose to Climate Change

The Paris climate talks are in full swing. Much about emissions and economics is being discussed in these negotiations, but one thing is missing from the conversation: wildlife. The spectacular diversity of creatures that share our warming planet also have a lot at stake in these talks. If climate change is left unchecked, it could threaten one in six of the planet’s species with extinction. Some of the effects of climate change on wildlife have received a lot of attention, particularly where beloved or iconic species are at risk. For instance, most people are aware there has been a rapid decline in Arctic sea ice (which hit a near-record low in 2015), and that this is a huge problem for polar bears and walruses. And higher summer temperatures in the mountains of the western U.S. threaten cold-adapted species like the adorable pika.

But that’s just the tip of the, ahem, iceberg. Greenhouse gas emissions are warming our planet at such a rapid pace that we risk altering the world’s habitats beyond the ability of species to adapt and respond. And climate change isn’t happening in a vacuum. These species also face habitat destruction, pollution, the spread of invasive species, and illegal wildlife trade, some of which are exacerbated by climate change. The following are just three examples of species that are already facing the impacts of climate change. These and other wildlife need us to come to an agreement to sharply limit the magnitude of future warming if they are to have a chance at survival.

Hawaiian Honeycreepers – Warming Temperatures Spread Deadly Disease

The Hawaiian honeycreepers are a group of bird species descended from finches that colonized the Hawaiian Islands from Asia and eventually diversified into over 40 species across the islands. Unfortunately, the birds’ long period of isolation from outside influences made them highly susceptible to the threats that accompanied human colonization of Hawai’i, particularly habitat loss and the introduction of predators and diseases. One of these introduced diseases has taken a heavy toll on Hawaiian honeycreepers: avian malaria, which is transmitted by mosquitoes. Development and transmission of this deadly parasite are temperature-dependent. For centuries, this meant that forests above about 5,000 feet in elevation were cool enough to be malaria-free refuges for some species. Unfortunately, climate change is shrinking that safety zone. On the Big Island, 2001-2002 saw warmer than usual temperatures, and along with them a spike in malaria in areas up to 6,000 feet. On Kauai, warming temperatures have led to more cases of malaria in birds in medium- and high-elevation locations over the past 20 years. Of the 41 known species of honeycreepers, 17 are extinct, six are likely extinct, and 18 are imperiled. Many of these are critically imperiled, with just a few birds remaining in the wild—and as the climate warms, increasing cases of malaria could drive those over the brink as well.

Coral Reefs – Threat Convergence

Coral reefs cover a tiny fraction of the ocean floor, but their value to fisheries, tourism, and coastal protection can be measured in billions of dollars. The key to their success is the symbiotic relationship between the coral animal—a tiny invertebrate related to jellyfish—and photosynthetic algae. The coral provides the algae with carbon dioxide, the building block of photosynthesis, important nutrients like nitrogen and phosphorus, as well as a protected place to live. In turn, the algae provides the coral with up to 90% of the food it needs, as well as oxygen. The reefs formed by hundreds of years of this symbiosis provide habitat for countless other marine invertebrates and young fish, which in turn support species of sharks, whales, sea turtles and other creatures. Corals are found exclusively in clear, shallow waters and are highly sensitive to sedimentation and pollution.

Climate change is causing three major impacts to corals: bleaching, disease and acidification. Bleaching occurs when the colorful photosynthetic algae are expelled from the coral, often when waters are unusually warm. Higher temperatures also stress corals, making them more vulnerable to diseases, especially those that develop more quickly in warmer waters. Finally, large amounts of carbon dioxide have been dissolving into the oceans, causing them to become more acidic than they were through most of history. More acidic waters make it harder for corals to build the external skeletons that form the coral reefs’ structure. Since new coral reefs take a very long time to develop even under the best of conditions, the speed at which we are warming the oceans is putting us at real risk of losing these “rainforests of the sea.”

Sononoran Pronghorn – Pushed to the Brink by Drought

The Sonoran pronghorn is a critically endangered subspecies of America’s fastest land animal. Pronghorn—sometimes misnamed “antelope”—range across much of the West, and have a top speed of almost 60 miles per hour, fast enough to outrun their long-extinct predator, the American cheetah. The Sonoran desert subspecies is uniquely adapted. Compared to other members of the species, they are smaller-bodied and lighter-colored, which helps them stay cooler, and they can eat cactus and other tough desert plants in addition to grasses and broadleaved plants.

The U.S population of Sonoran pronghorn has the distinction of having very nearly been driven to extinction by a climate event: A 13-month severe drought that struck Arizona over 2001-2002. The intense dry period hit pronghorn habitat hard. Vegetation dried up, and already-scarce water sources vanished. Every single fawn born in 2002 died, as did most of the adults. The population plunged from about 140 animals to just 19. Wildlife managers had to resort to emergency measures to save the species, initiating a captive breeding program and embarking on an ambitious project to create artificial water sources and forage plots in the wildlife refuges that form the core pronghorn habitat. With the region’s climate projected to become much drier under a high emissions scenario, particularly in the critical spring breeding season, the pronghorn could be pushed back to – or over – the brink of extinction.

While much of Defenders’ policy work is aimed at helping species and habitats adapt to climate change’s effects, the effort underway in Paris is critical because no amount of adaptation will preserve biodiversity if the worst-case warming scenarios occur. For these species and countless others, a strong climate agreement in Paris may well be the key to their survival.

All Eyes on Paris. This blog is the second in a four-part series on international climate negotiations in Paris. Our first entry introducing the Paris talks is posted here. In our next installment, we will look at some of the ways that the U.S. intends to reduce our carbon footprint – and at Defenders’ efforts to make sure that wildlife conservation goes hand in hand with our clean energy transition.