Life on earth
The Economist, Sept 13, 2007.
More species are under threat than ever before according to the World Conservation Union. Its Red List, published on Wednesday September 12th, gives warning that 16,306 species are under threat of extinction (of 41,415 described), nearly 200 more than in 2005. This number has risen steadily since the first report in 1996. Corals have been added to the endangered list alongside the usual apes and dolphins. There is cause for concern but biodiversity scientists are less confident accountants than the list might suggest.
Nobody knows how many species occupy the planet. Most experts think 10m is roughly correct, though they have only formally noted 1.4m. The most reliable data describe creatures that humans find easy to count: colourful, land-based and big enough to hunt.
According to the WCU, the number of threatened species was just over 10,000 in 1998. By 2003, it had risen to more than 12,000 species. By 2007, the figure had risen to more then 16,000 species in danger of extinctions.
Climate Change Brings Risk of More Extinctions
BLACKWATER NATIONAL WILDLIFE REFUGE,
Visitors can see ospreys gliding overhead, egrets wading in the channels and Delmarva fox squirrels making their unhurried commutes between pine trees.
But then the road turns a corner, and Blackwater's marsh yields to a vast expanse of open water. This is what's missing: There used to be thousands more acres of wetland here, providing crucial habitat for creatures including blue crabs and blue herons. But, thanks in part to rising sea levels, it has drowned and become a large, salty lake. "If people want to see the effects" of Earth's increasing temperature, refuge biologist Roger Stone said, "it's happening here first."
But not just here. Around the world, scientists have found that climate change is altering natural ecosystems, making profound changes in the ways that animals live, migrate, eat and grow. Some species have benefited from the shift. Others have been left disastrously out of sync with their food supply. Two are known to have simply disappeared.
If warming continues as predicted, scientists say, 20 percent or more of the planet's plant and animal species could be at increased risk of extinction. But, as the shrinking habitat at Blackwater shows, the bad news isn't all in the out years: Some changes have already begun. "This is actually something we see from pole to pole, and from sea level to the highest mountains in the world," said Lara Hansen, chief climate change scientist at the World Wildlife Fund, a private research and advocacy group. "It is not something we're going to see in the future. It's something we see right now."
The temperature increase behind these changes sounds slight. The world has been getting warmer by 0.2 degrees Fahrenheit every decade, a U.N. panel found this year, in part because of carbon dioxide and other human-generated gases that trap heat in Earth's atmosphere.
By nature's clock, the warming has come in an instant. The mechanisms that helped animals adapt during previous warming spells -- evolution or long-range migration -- often aren't able to keep up. Scientists say that effects are beginning to show from the Arctic to the Appalachian Mountains. One study, which examined 1,598 plant and animal species, found that nearly 60 percent appeared to have changed in some way.
"Even when animals don't go extinct, we're affecting them. They're going to be different than they were before," said David Skelly, a Yale University professor who has tracked frogs' ability to react to increasing warmth. "The fact that we're doing a giant evolutionary experiment should not be comforting," he said.
Some of the best-known changes are happening near the poles, where the air and the water are warming especially quickly. As they do, sea ice is receding. For some animals, this has meant literally the loss of the ground beneath their feet.
Polar bears, for instance, spend much of their life on the Arctic ice and use it as a hunting ground for seals. When ice on Canada's western
Walruses, too, rely on the ice; mothers stash their calves on it, then dive down to feed on the ocean floor. When ice recedes from prime feeding areas, mothers and calves can get separated.
In 2004, University of Tennessee professor Lee W. Cooper was off the north Alaskan coast when he saw about a dozen calves swimming toward his boat. His theory: The calves, alone and desperate without ice nearby, thought the boat might be a large iceberg.
There was nothing the scientists could do to help, Cooper said. "I think they were doomed."
Other changes have been less deadly, but they show centuries-old patterns shifting. Scientists have noticed changes in the timing of seasonal migrations, presumably caused by the earlier onset of warm weather.
In some cases, migrating animals suddenly find themselves out of rhythm, missing the weather conditions or the food they need. In parts of the Rocky Mountains, American robins arrive two weeks earlier than they used to -- and often discover the ground snow-covered and little food to be found.
In other cases, an animal's entire territory that shifts, as old habitats become too warm. In many cases, this means a move north. In others, it means a move up.
The American pika, a small rodent that lives on the slopes of mountains in the western
In some cases, there is no escape. In Costa Rica's Monteverde Cloud Forest, a famous region that is kept damp by fog and mist, climate change has brought more variable weather and less of the clouds that some animals need.
Two amphibian species -- the golden toad and the Monteverde harlequin frog -- have not been seen since the late 1980s. These may be some of the first extinctions linked to climate change, said cloud forest researcher Alan Pounds. "It's been an interesting puzzle to work on," Pounds said. "But, at the same time, very alarming and frightening."
At the Blackwater refuge, it is rising waters, not rising temperatures, that are eliminating habitat. A quirk of geology means that water rises especially fast here: Paradoxically, the land in this area is sinking as North America slowly unbends from the weight of glaciers during the last ice age.
Add that to the effect of melting polar ice, and scientists expect that most of the marsh will become open water by 2030. When it goes, there could be a shortage of habitat for the
"Birds will return for spring migration, and they'll be looking for territory, and there just won't be enough territory to go around," he said.
So what happens then?
"They'll . . ." he paused, looking for the right word, ". . . die. They'll disappear."
Not all animals, of course, will suffer. There are examples of creatures that are thriving in a warmer world. Fish such as pollock and pink salmon have begun moving into now-warmer Arctic waters. In the northern woods of
Livestock herds might increase in a warmer world, an analysis by the Agriculture Department found. That's because food crops such as corn and rice could become harder to grow if the fields dry out, leaving more land for grazing. Researchers say that, even if all greenhouse-gas emissions were shut off today, the gases already in the atmosphere will cause Earth to warm for years to come. But, many say, it's still imperative to reduce these emissions to head off even more warming.
"Unfortunately, it takes a generation or two to turn this supertanker around," said Stephen Schneider, a professor at Stanford University, talking about the climate change already in progress. But still, he said, it is important to start trying. "What we're looking at is a planetary environmental train wreck if we don't start some compromising here."
Already, some are trying to make it easier for wild animals to adjust. In Australia, conservationists are trying to set aside a north-south cordon of open land so animals can move if they need to. In the western
Overall, scientists say, the news of climate change will not be bad for all animals. But, they say, that's cold comfort for the rest -- and for humans, as well, if it means that we watch some of the planet's most beloved species decline or disappear.
"Yeah, the earth will recover," said Scott Wing, who studies the biology of previous eras at the Smithsonian Institution. But, he said, "would you have wanted to be one of the dinosaurs when the asteroid hit? No."
Code red for threatened species
ENN.com, Sept. 14, 2007
The Red List of Threatened Species acts as a barometer that shows the effects habitat loss and degradation, over-exploitation, pollutants and climate change are having on our planet.
"We're at code red," said Dr Susan Lieberman, Director of WWF's Global Species Programme.
"It's about time people stopped talking and realized this is not a game. The very future of our planet -- and the environment we leave to our children -- hangs in the balance. Do we really want to be remembered as the generation that got it so wrong?"
According to WWF, the loss of species is a clear warning for humans. Sound ecosystems which include clean fresh water, safe seas and healthy forests with robust species populations, are critical to the livelihoods and survival of people.
WWF applauds IUCN for drawing attention to this situation and calls on governments to take immediate, concrete, action to address some of the root causes of species extinction.
WWF believes that the IUCNs Red List classifications should be used as a tool to assist in prioritizing focus for limited resources.
For example, the western gorilla has moved from Endangered to Critically Endangered. The upgrade in status on the list should highlight the plight of these gorillas, whose population numbers prove the need for urgent attention to combat commercial hunting and further understand and prevent ebola outbreaks.
Orang-utans are also under extreme threat, primarily due to destruction of their habitat for activities such as the creation of oil palm plantations. WWF and its partners have issued new guidelines to ensure that oil palm plantations are better situated and managed more effectively to prevent conflict between the animals and humans. It is critical that oil palm companies in orang-utan range states take these on board.
Freshwater dolphins are suffering a dismal fate globally due to dam-building, entanglement in fishing nets, boat traffic and pollution. In 2005, WWF launched a River Dolphin Initiative with governments, other non-governmental organizations, industry, fishermen, and local communities to reduce or eliminate the threats to river dolphins and porpoises.
Overexploitation of species for food, medicine, pets and other human uses is a direct driver of species loss. The impact of international trade on wildlife is tremendous, and when it is not properly regulated it causes rapid declines, as seen for some of the species highlighted by the IUCNs Red List, particularly reptiles from
Corals are also on the list for the very first time.
"The fact that corals are now present on the IUCNs Red List should sound warning bells to the world that the oceans are in trouble", said Dr Simon Cripps, Director of WWF's Global Marine Programme.
Coral reefs are crucial as nursery grounds for thousands of species of fish and invertebrates, and provide revenue and livelihoods from fishing and tourism for a large proportion of the world's growing coastal population.
Corals across the world are being decimated by unsustainable and destructive fishing and by the effects of climate change. WWF believes that unless the world acts urgently, the corals now listed will soon be accompanied by yet more species, and a loss of revenue for dependent communities.
"World leaders have made various commitments to halt biodiversity loss, but this crisis has largely fallen off political agendas," Dr Lieberman added.
"Attention and funding have shifted to economic development and long-term security -- without adequate attention to the link between these issues, a healthy environment, and truly sustainable development. It's time to make the connections."
WWF believes the IUCN Red list is an important science-based conservation tool that should be used across the globe by communities, governments and international fora to drive funding and decision making. Reversal of the negative trend is possible when political motivation is high and when local communities see the value and benefit from conserving species.
The Red List is developed by a voluntary network of IUCN Species Specialist groups. WWF works in close cooperation with IUCN across the globe, through field interventions and by providing financial and technical support to the various Species Specialist groups of the IUCN Species Survival Commission.