This is the first part of a series on the effects of global warming in Antarctica.
At 28 degrees, this blue stretch of antarctic ocean is so cold only the salt keeps it from freezing. That's just the way Adelie penguins like it. But this march of the penguins is becoming increasingly perilous.
Biologist David Ainley has been studying Antarctic penguins for 12 years.
He took CBS News correspondent John Blackstone to Cape Royds, a spectacular place few people ever see, to show the unexpected impact of global warming.
So far, climate change has been good for the penguins of Cape Royds. Clearing ice has left plenty of open ocean for feeding. But the air is still frigid, averaging just 15 degrees in the summer.
"In the short term, Cape Royds is the place to be if you're a penguin," said Ainley.
This year, 5,000 Adelie penguins converged at Royds to breed and raise their young.
"Penguins are the favorite of a lot of people. They look like little people," said Ainley.
CBS News first visited Ainley in 1999. Penguins need sea ice but back then, there was too much of it. This forced the penguins to walk for miles to get to the ocean. Those chubby chicks are among the parents at Cape Royds today. The chubby chicks we photographed then are among the parents at cape royds today.
As cute and curious as they are, these penguins are also pretty tough. But in antarctica, there are fewer and fewer places that are just right. While the population is thriving on Cape Royds, on the peninsula colonies are collapsing. There, temperatures have risen five times faster than in the rest of the world.
"Basically, penguins are moving in large numbers from areas that are no longer suitable," says Ainley.
Meaning, areas where temperatures are rising too fast to keep the ice they need in place.
"They must have ice to live," said Ainley's assistant Jean Pennycook. "So like many songbirds require trees, if you cut down the trees, the songbirds won't be there anymore. If the ice goes away, these penguins will no longer be able to survive."
"When we see species like penguins having to make these changes, it's an indication we may have to make these changes," said Pennycook.
Increasingly severe climate changes in Antarctica are having devastating effects on some of the colonies Ainley and Pennycook study.
A colony Pennycook was studying on Cape Bird is at the base of a very large glacier. She photographed that glacier as it rapidly melted, flooding the colony and leaving penguins struggling to keep their eggs above water.
"It was very sad," she said.
"It's not so much about global warming, but about climate change. But when there's more warmth, that means more evaporation, and that means more storms," says Pennycook.
For now, the complex interactions of a changing climate seem to favor this one small colony at Cape Royds. But this really is the end of the earth--as far south as penguins can go in search of the cold climate essential to their survival.
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