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  Yahoo News 26 Mar 07
Warming may create climates, cut others
By Randolphe E. Schmid, AP Science Writer

PlanetArk 27 Mar 07
New, Unknown Climate Zones Seen By 2100 - Study
Story by Deborah Zabarenko

National Geographic 27 Mar 07
Warming to Create Previously Unknown Climates, Study Says
Hannah Hoag for National Geographic News

Yahoo News 27 Mar 07
Sweeping changes to global climate seen by 2100: study

Many of the world's climate zones will vanish entirely by 2100, or be replaced by new, previously unseen ones, if global warming continues as expected, a study released Monday said.

Rising temperatures will force existing climate zones toward higher latitudes and higher elevations, squeezing out climates at the colder extremes, and leaving room for unfamiliar climes around the equator, the study predicted.

The sweeping climatic changes will likely affect huge swaths of land from the Indonesian rainforest to the Peruvian Andes, including many known hotspots of diversity, disrupting local ecological systems and populations.

"Our findings are a logical outcome of global warming scenarios that are driven by continued emissions of carbon dioxide and other greenhouse gases," said Jack Williams, a professor of geography at the University of Wisconsin-Madison, and author of the paper. "The warmest areas get warmer and move outside our current range of experience and the colder areas also get warmer and so those climates disappear."

Williams and colleagues from the University of Wyoming based their predictions on computer models that translate carbon dioxide and greenhouse gas emissions into climate change. The emissions' estimates were taken from a report issued by the UN's Intergovernmental Panel on Climate Change in February.

The models suggest that the climate zones covering as much as 48 percent of the earth's landmass could disappear by 2100. By that point, close to 40 percent of the world's land surface area would also have a "novel" or new climate, according to the climate models.

Even if emission rates slowed due to mitigation strategies, the changes would still affect up to 20 percent of the earth's landmass in each scenario, the authors said.

As a geographic phenomenon, the disappearing climates would likely affect tropical highlands and regions near the poles including the Colombian and Peruvian Andes, Central America, African Rift Mountains, the Zambian and Angolan Highlands.

The trend poses the greatest threat to areas of rich, but threatened, animal and plant life, in regions such as the Himalayas, the Philippines and African and South American mountain ranges.

The changes could threaten some species with extinction and also displace or fragment local human populations.

As for new or novel climate zones, the phenomenon will largely affect the tropics or sub-tropics, such as the Amazonian and Indonesian rainforests, where even subtle temperature variations can have far-reaching effects, Williams said. The study is published in the Proceedings of the National Academy of Sciences.

Yahoo News 26 Mar 07
Warming may create climates, cut others
By Randolphe E. Schmid, AP Science Writer

Some climates may disappear from Earth entirely, not just from their current locations, while new climates could develop if the planet continues to warm, a study says.

Such changes would endanger some plants and animals while providing new opportunities for others, said John W. Williams, an assistant professor of geography at the University of Wisconsin, Madison.

Using global change forecasts prepared for the Intergovernmental Panel on Climate Change, researchers led by Williams used computer models to estimate how climates in various parts of the world would be affected. Their findings are being published in this week's online edition of Proceedings of the National Academy of Sciences.

The IPCC, representing the world's leading climate scientists, reported in February that "warming of the climate system is unequivocal, as is now evident from observation of increases in global average air and ocean temperatures, widespread melting of snow and ice and rising global average sea level."

Tropical regions in particular may face unexpected changes, particularly the rain forests in the Amazon and Indonesia, Williams' researchers concluded.

This was surprising, Williams said in a telephone interview, since the tropics tend to have little variation in weather.

But that also means temperature changes of 3 or 4 degrees in these regions might have more impact than a change of 5 to 8 degrees in a region that is accustomed to regular changes.

Species living in tropical areas may be less able to adapt, he said, adding that that is speculative and needs further study.

Areas like the Southeastern United States and the Arabian Peninsula may also be affected, the researchers said. And they said mountain areas such as in Peruvian and Colombian Andes and regions such as Siberia and southern Australia face a risk of climates disappearing altogether.

That doesn't mean these regions would have no climate at all — rather their climate would change and the conditions currently in these areas would not occur elsewhere on Earth. That would pose a risk to species living in those areas, Williams observed.

If some regions develop new climates that don't now exist, that might provide an opportunity for species that live there, Williams said.

"But we can't make a prediction because it's outside our current experience and outside the experience of these species."

Alan Robock, a professor of environmental sciences at Rutgers University welcomed the report, calling it the first he has seen "that not only looks at species extinctions, but also looks at regions where novel climates will appear."

"While the idea of novel climates may seem like a positive consequence of humans using the atmosphere as a sewer and causing rapid, unprecedented climate change, I would argue that mitigation of our pollution should be an even stronger reaction to these results," said Robock, who was not part of the research team.

"The potential consequences and how these new regimes will be populated are poorly known, and the potential for new threats to humans through disease vectors could be a real danger," he said.

National Geographic 27 Mar 07
Warming to Create Previously Unknown Climates, Study Says
Hannah Hoag for National Geographic News

Global warming will redraw Earth's climate map by the end of the century, causing some of today's climates to disappear and creating other climates unlike anything known today, according to a new study.

Specifically, brand-new climates will appear in the tropical and subtropical regions, while some climates of the tropical mountains and the regions around the Poles will be entirely replaced by 2100.

For the new study, researchers used forecasts from the most recent report from the Intergovernmental Panel on Climate Change (IPCC) to create a computer model that estimates how different parts of the world would be affected by warming. The results appear in this week's issue of the online early edition of the Proceedings of the National Academy of Sciences.

"So much of the novel and disappearing climates are occurring at the low latitudes [around the Equator]," said study co-author Steve Jackson of the University of Wisconsin, Madison.

"None of us expected this." That's because Jackson and colleagues thought the greatest shifts would happen at Earth's Poles, where the largest temperature changes are expected to occur.

Instead, small changes in temperature and humidity in other regions, particularly in the tropics, will have greater affects on those overall climates, the study shows.

The researchers also found that the predicted changes could trigger local extinctions, reshuffle current plant and animal communities, and make conservation efforts more difficult.

From Novel to Nonexistent

Jackson and colleagues' computer model shows that the overall climates of North America and Europe will shift, but will resemble climates we already know. The Florida peninsula, however, will develop a never before seen climate that is much hotter and drier in the summer.

The Amazon Basin will also develop a new climate that will be hotter and wetter between June and August than it is now, the model predicts.

"It won't be like anything we've experienced since the last interglacial period," Jackson said. "Some of these novel climates have probably never existed on Earth, or at least not in the last few million years."

At the same time, climates along the highest points of the Andes mountains of South America will disappear due to temperature increases. "These are the coolest parts of the tropics, and that climate is being pushed off the mountaintops and into the atmosphere," Jackson said.

The climates of the mountains along Africa's Great Rift Valley, southeast Australia, portions of the Himalaya, the Indonesian and Philippine archipelagos, and some circum-Arctic regions are also among those that will disappear, according to the model.

Hot Spots at Risk

The predicted changes would create conservation challenges, the authors note, because many of the areas where climates are disappearing are concentrated in biodiversity hot spots--areas rich with unique and threatened plants and animals.

Climate change appears to already be causing extinctions for some species, especially those confined within narrow temperature ranges and those living in colder parts of the globe

"Some species will respond quite quickly to climate change and move into a region or out of a region, but others will move more slowly," said John Williams, a study co-author also at the University of Wisconsin, Madison.

When a climate disappears, some of the plants and animals adapted to it might not be able to adjust or migrate to a friendlier but far-away climate.

"Plants in biodiversity hot spots [for example] are very poor at dispersing their seed" in a relatively short time frame, said Guy Midgley of the South African National Biodiversity Institute. "There is very little chance that they would be able to disperse on the order of tens of kilometers, let alone hundreds of kilometers."

And animal species that are already at risk wouldn't be helped by traditional conservation techniques such as reintroducing captive-bred creatures to the wild if their native habitats are drastically altered.

Even more radical moves such as assisted migration would no longer be viable if the animals didn't have a receptive region to move to.

Alan Pounds is a biologist at the Monteverde Cloud Forest Preserve in Costa Rica, where he has linked amphibian declines to climate change. "We could lose entire cloud forest communities. As climate spaces disappear, it will be very difficult to save species," Pounds said. "We're going to lose a large number of species if we don't reduce our greenhouse gas emissions."

PlanetArk 27 Mar 07
New, Unknown Climate Zones Seen By 2100 - Study
Story by Deborah Zabarenko, Environment Correspondent

WASHINGTON - Global warming could re-make the world's climate zones by 2100, with some polar and mountain climates disappearing altogether and formerly unknown ones emerging in the tropics, scientists said on Monday.

And when climate zones vanish, the animals and plants that live in them will be at greater risk of extinction, said Jack Williams, lead author of a study published in the journal Proceedings of the National Academy of Sciences.

"What we've shown is these climates disappear, not just regionally, but they're disappearing from the global set of climates, and the species that live in these climates really have nowhere to go as the system changes," said Williams, a geographer at the University of Wisconsin-Madison.

Previous studies have raised the concern about species extinctions in specific areas -- such as the cloud forest of Costa Rica or the Cape region in South Africa -- but this is the first to predict this global change, Williams said in a telephone interview.

As Earth warms, predicted to happen by up to 15 degrees F (8 degrees C) at some latitudes by the end of this century, climate zones are likely to shift away from the equator and toward the poles, the study said.

"It's those climates near the poles or at the tops of mountains that are being pushed out...," Williams said. "It's getting too hot." Polar bears and ring seals, which depend on Arctic ice, could be among those species threatened by the shifting of climate zones, Williams said, but the study did not specifically address the fate of these animals.

As polar climate zones disappear, new zones will be created in the parts of the world that are already the hottest, the study predicted, using models of climate change. The change in temperature is likely to be greater in the Arctic and Antarctic because when snow and ice melt, their ability to reflect sunlight goes away too, accelerating the warming effect.

However, because normal fluctuations in temperature and rainfall are smaller in the tropics, even small changes in temperature can make a big difference in this warm region, co-author John Kutzbach, also of the University of Wisconsin-Madison, said in a statement.

Williams attributed the warming to the building of carbon dioxide and other greenhouse gases in the atmosphere. A report in February by the Intergovernmental Panel on Climate Change said that with 90 percent probability, human activities are responsible for the warming of the planet.
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