|August 21, 2012|
Nine Ways Climate Change Is Throwing Animal Populations 'Out Of Kilter'
|Well over half the country is suffering from extreme drought, and locally, pets and animals are struggling with the effects of climate change as well. Triple-digit temperatures have gripped much of the U.S. this summer, and extreme heat, which NASA's James Hansen wrote is "almost certainly" connected to climate change, can have a serious impact on animal biodiversity, as food grows scarcer and a wide variety of habitats dry out.|
"The whole ecosystem is going to have to move north as the climate gets warmer to look for comfortable temperatures.... [L]ife events, migrations, and egg laying, and flowering and so on are changing, but they're changing at different rates, and that makes an ecosystem that has evolved in a cooperative way over the last couple thousand, or 10,000, or 100,000 years --- it throws it out of kilter," science journalist Michael Lemonick said on NPR.
There are many ways a climate on steroids throws animals and biodiversity "out of kilter":
Rare Canadian wildfires endanger polar bear habitats
Because food resources are typically scarce during the summer, female Hudson Bay polar bears retreat to underground dens to rest and raise vulnerable young. However, unusually warm and dry weather in the region has allowed several wildfires to spring up and weakened permafrost, putting many of these century-old refuges in danger of collapse. And, of course, "The survival of polar bears as a species is difficult to envisage under conditions of zero summer sea-ice cover," concluded the 2004 Arctic Climate Impact Assessment, by leading scientists from the eight Arctic nations, including the United States. We are headed toward those conditions in the next decade or two.
Snow leopards lose hunting ground
Snow leopards are currently losing hunting ground as new weather patterns push treelines further into their territory. Their current habitat is projected to decrease by 40% in the next century, seriously impacting the already struggling population, thought to number just 500. WWF snow leopard expert Rinjan Shrestha says, "Loss of alpine habitat not only means less room for snow leopards, but also has the potential to bring them closer to human activities like livestock grazing."
Wolverines rely on disappearing snow
A study by the Wildlife Conservation Society suggests that wolverines may rely on snow as a form of natural refrigeration for their food, the Huffington Post reports. Wolverines typically give birth during a limited period early in the year, and rely on caches of stored food to raise their young during lean times, making them particularly vulnerable to the effects of climate change. Wolverines were flagged as a new candidate for protection in 2010.
Southern species travel north
Sightings of Southern animals--including Grizzly bears, red fox, white-tailed deer, Pacific salmon, and killer whales--have recently increased in arctic regions. Many scientists now believe that climate change is responsible for removing key barriers that previously prevented southern animals from traveling north, and new competition may have serious ramifications for Arctic biodiversity. Killer whales have been known to eat beluga whales and narwhal, and a red fox was filmed killing its arctic counterpart. Observations of new hybrid grizzly-polar bears have scientists worried about the dilution of the gene pool--a change that is likely impossible to reverse.
Snowshoe hares may struggle to camouflage
Snowshoe hares rely on their camouflage for survival. They shed their coats twice a year, shifting from brown to white seasonally, and Biologist L. Scott Mills found that hares are most likely to die during the transitional periods of fall and spring, when their coloring is mixed and their camouflage imperfect. Hare coloration changes have been correlated to seasonal changes in sunlight, not snowcover, so a future of unpredictable weather patterns may leave them increasingly vulnerable to predation.
Arctic Caribou Herds on the Decline
Caribou populations are in steep decline in many Arctic regions, Environment360 reports. Of the 43 major herds that scientists have tracked in the past decade, 34 are in decline, and population numbers have fallen 57% from historical highs. Some have seen more drops in numbers: the Bathurst herd in Canada has lost 93% since 1986. Scientists say that unusually high Arctic temperatures are responsible for the decline, and that Arctic resource-development projects have compounded the problem by cutting down the caribou's natural range. Indigenous people in the region rely on caribou populations for food and clothing resources.
Massive coral bleaching tied to warmer temperatures
Scientists have observed several cases of mass-bleaching in the world's coral reefs in the past 20 years. In high light conditions and with unusually warm waters, the algae that coral relies on produces excessively high levels of oxygen, which can be toxic to marine life. When this happens, coral either expels the algae, losing a key source of photosynthetic fuel and often dying as a result, or dies directly from the toxin. Oceans are the world's most significant heat sinks, and maintain a far more constant temperature than weather-exposed land habitats. This makes it difficult for their inhabitants to find ways to beat the heat.
Destructive beetles flourish in warmer temperatures
The coffee berry borer is an insect that burrows into coffee berries to lay its eggs, killing the plant. Researchers estimate that the insect causes approximately $500 million in damage to the coffee industry each year, and say that it is becoming an increasingly serious problem as temperatures rise. Research shows that the pesticide-resistant beetle produces more eggs and burrows deeper into the coffee berry when temperatures are higher. Scientists project that coffee growers will have to move up 550 feet in altitude for ever 1.8° F increase in order to stay ahead of the damage.
Oceans face an oxygen crisis
Away from coral reefs, inhabitants of the world's oceans are struggling from a severe lack of oxygen, prompting an increase of "dead zones" around the world. A 2009 Nature Geoscience study found that these dead zones, "devoid of fish and seafood" are poised to expand and "remain for thousands of years." Pollution from agricultural runoff and fossil fuels are key culprits, but warming weather may have a serious impact as well. Though the heat may help surface level algae produce higher levels of oxygen, scientists say that warmer water is less able to hold the dissolved oxygen and increased temperatures makes surface water lighter, decreasing the amount of water circulation. This may deprive deeper regions of the much-needed resource, causing fish to suffocate.
Climate change has already had a marked impact on a wide variety of species. Though some may be able to adapt to the new environment, some researchers warn that the possibility of adaptation depends on the stability of the environment. An increasingly extreme environment has severe implications for biodiversity and complicate successful adaptation, seriously impeding the stabilization of these populations.