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發表於 2011-9-8 02:41 PM
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[環保資訊] 2009 Ten Climate Change "Icons" Announced
本帖最後由 dxb 於 2011-9-9 07:16 AM 編輯
Hi People.... This may not be new, but still i would like to share this with everyone on the threat of climate change.
How it affect the world...
Ringed Seal
December 14, 2009--Like polar bears, ringed seals (above, a newborn rests in the snows of Nunavut, Canada) depend on summer sea ice in the Arctic for their survival. No one knows what will happen to the seals and other species if polar summer ice completely disappears due to global warming--which may occur in the Arctic by 2040, experts say.
That's one of the reasons the seals, along with arctic foxes, emperor penguins, and beluga whales, are among ten "flagship" species named in a new report by the International Union for Conservation of Nature (IUCN), which highlights the diversity of global warming's impacts on wildlife.
Many of the species featured in the new report, released today at the Copenhagen climate change conference, already appear on IUCN's Red List of Threatened Species for other reasons, such as habitat destruction and overharvesting.
This makes climate change an "additional and major threat," the report authors say.
Emperor Penguins
Crumbling ice shelves in the Antarctic are already affecting breeding colonies of emperor penguins (above, a penguin group dives under a breathing hole), according to the December 2009 IUCN report.
In warmer years ice sheets have broken apart early--right under the nesting penguins' not-so-happy feet--causing chicks to be swept into the ocean and drowned. If global average temperatures rise by 3.6 degrees Fahrenheit (2 degrees Celsius), almost 40 percent of the world's emperor penguin breeding colonies could become unviable, experts say.
Clownfish
The world's oceans may soon be losing Nemo. Clownfish, also called clown anemone fish, are suffering from habitat loss as global warming causes coral reefs to decline, the IUCN report says.
Clownfish rely on stinging sea anemones, which thrive on reefs, to provide shelter from predators. But rising water temperatures are thought to be causing widespread coral bleaching--when corals lose their symbotic algea and eventually die. Fewer live reefs mean fewer anemones, offering clownfish fewer places to hide.
What's more, increasing carbon dioxide in the atmosphere is making oceans more acidic, and higher acidity has been shown to block the chemical signals roaming clownfish use to find their way back to protective anemones.
Quiver Tree
Pink blossoms surround a spiky-topped kokerboom, or quiver tree, in South Africa. The desert plant, which can reach up to 32 feet (10 meters) tall, gets its name from the indigenous San hunters of Namaqualand, who cut the trees' branches to make quivers for their poisoned arrows.
Average temperatures have increased across the quiver tree's range in South Africa and Namibia, according to the December 2009 IUCN report. Drought-related stress over the past decade has already triggered mass die-offs of the trees near the Equator. Populations at the edges of the species' range are thriving, but these trees are less genetically diverse, experts warn.
Salmon
Earlier snow melt due to global warming will increase the rate of winter flow in freshwater streams, causing the fast-moving water to scour riverbeds when delicate salmon eggs and young are present, according to the IUCN report.
Summertime flows, in turn, will be reduced, possibly leading to a decline in freshwater habitat for adult salmon.
Arctic Fox
Melting snows in the northern tundra will likely be bad news for arctic foxes, like the animal seen above sporting its white winter coat, according to IUCN. A warmer climate means red foxes feel more at home farther north, and the predators are even now encroaching on the arctic fox's traditional range.
At the same time, the fox's prey--small rodents such as lemmings--are losing their wintertime homes in the spaces between the permafrost and a normally thick blanket of fluffy snow. Shorter, milder winters mean that the snowpack is thinner, wetter, and more prone to collapse, the report notes, possibly leading to a decline in rodents.
Leatherback Sea Turtles
Like some other reptile species, leatherback sea turtles' gender is affected by temperature--warmer average temperatures during egg development tend to produce more females. This means global warming has the potential to throw leatherback breeding populations out of whack, the IUCN report says.
In a warmer world, the already critically endangered sea turtles must also try to nest on beaches severely eroded by extreme storms, which have been linked to rising sea-surface temperatures.
Beluga Whale
Sea-ice loss in the Arctic could seriously impact the beluga whale by allowing humans better access to the species' once pristine range, according to the IUCN report. More vessels navigating Arctic waters could lead to an increase in ship strikes as well as noise and chemical pollution, which could put belugas on the decline.
A reduction in belugas may in turn affect local indigenous hunters, who rely on sustainable kills of large marine mammals, the report says.
Koala Bear
Rising carbon dioxide in the atmosphere is causing eucalyptus plants in Australia to produce leaves with fewer nutritious proteins and more unpalatable tannins, the IUCN report says.
This means that koalas, which eat only eucalyptus, will have to consume even more to keep from starving. In addition, the iconic marsupials are at risk from increased wildfires as heat and drought become more prevalent in Australia.
Staghorn Coral
Perhaps the most vulnerable species on the new IUCN list is the staghorn coral, which has been greatly weakened by bleaching and is at risk of erosion due to increased ocean acidification.
Bleaching occurs when warmer oceans cause corals to lose their symbiotic algae, leaving the blanched reefs to slowly perish. Meanwhile, acid oceans eat away at stony corals' skeletons.
Although experts note that it's possible for species to adapt to a warmer world, that depends on how quickly climate change will occur. As of Monday, draft negotiations at the Copenhagen climate talks would allow Earth's carbon dioxide levels to rise to 650 parts per million by 2100, which in turn would warm the Earth by up to 5.4 degrees Fahrenheit (3 degrees Celsius).
According to Kassie Siegel, of the California-based, nonprofit Center for Biological Diversity, such a rapid rise would "equal extinction for essentially all of these species, plus thousands of others." |
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