Daniel Schweimler, BBC News 28 Apr 08;
Earlier in April, UK scientists attending a conference in Vienna warned that sea-levels could rise by up to 1.5 metres by the end of this century, putting low-lying countries such as Bangladesh under threat.
One of the main causes is the rapidly melting glaciers which cover huge areas of the world's surface - mostly in the Antarctic, Greenland and the south of Argentina and Chile.
Glaciers melt and grow naturally, but the rate of change is raising concerns.
Two million hectares of ice are found in the Magellan Strait at the southern tip of South America. Charles Darwin came here in the 1830s.
It is where he began to formulate his Theory of Evolution, before sailing on to the Galapagos Islands.
But the remoteness and difficult weather conditions, as well as the high cost of transport, mean few have studied in this particular area since.
As a result, there is little scientific data about the fauna and flora of the Tierra del Fuego region.
But there is plenty of anecdotal evidence from the few who work here - fishermen and tour guides.
Early penguins
A huge lump of ice falling from the melting Pia glacier is a dramatic sight. Tourists gasp in wonder.
Mauricio Alvarez has been bringing tourists here on the Australis cruiser for six years and has seen significant changes in that time.
"This is one of the highlights of our journey," he said.
"We have a very personal opinion about the behaviour of this glacier. We're not really sure. It's really hard to determine whether it's advancing or growing or whatever. But the effects of global warming are undeniable down here."
The tourists should also have seen penguins, but the birds refused to cooperate and migrated, several weeks earlier than in previous years.
Those who have been observing them believe this is because temperatures are rising.
Another person who has been living and working in these remote and often hazardous waters for many years is Sergio Ruiz.
He was a fisherman, then a ship builder and now works as the bosun on the Australis.
Standing on the deck in a short-sleeved shirt in freezing temperatures he told me that in 10 years he has seen dramatic changes.
"The glaciers, you can see they have moved backwards or forwards.
"You can easily see the changes, on the beach area for instance. From one week to another, if you do the same route all the time you can't help note the changes."
The cruiser also carries scientists, desperate to get to the area and confirm, or not, what the fishermen and tourist guides are telling them about what all believe to be the effects of global warming.
Diving down
Americo Montiel San Martin and Cesar Cardenas are from the University of Punta Arenas in southern Chile and are two of the few marine biologists to have dived in the icy waters of the Magellan Strait.
Mr Cardenas has discovered several sub-species.
The two researchers have come with diving dry-suits and underwater cameras.
Their plans to dive are often thwarted by strong currents and bad weather.
Both said they were pretty much starting from scratch since, apart from the 19th Century works of Charles Darwin, they have very little scientific data to work with.
They are starting small, studying plankton and seaweed.
"There's plenty of studies on the romantic animals - the penguins and killer whales, but very little on the tiny stuff," says Mr Cardenas.
Dinghies take us from the ship to a small beach which the researchers say has probably never been investigated. Dolphins accompany us on both sides.
The marine biologists were hoping to find a spot on the rocky bottom to conduct long-term studies on the changing habits of the life forms that inhabit the icy waters.
But as he emerged from the water Mr Cardenas wore a look of disappointment.
"Plenty of sand and king crabs and kelp," he said. "But it's not for us. We'll have to keep looking."
Pressing questions
The Magellan Strait is home to 11 major glaciers and hundreds of smaller ones.
Some are melting at a rapid rate while others are growing. No-one really knows why.
The glaciers began their retreat from this region just 7,000 years ago, so the life that then bloomed here is still relatively young.
Mr Montiel was cautious about blaming global warming for the changes, aware of the scarcity of data and the need for long-term research.
But what proof do they need that global warming is having an impact?
"There are creatures that live in cold water," he explained.
"And if we start to find creatures that like the warmer water, then that would be a strong sign.
Few doubt that the compromised ozone layer and human behaviour thousands of kilometres from here are having an effect.
The changes have increased the desire for scientists such as Mr Montiel and Mr Cardenas to follow in the footsteps of Charles Darwin.
Their work is only just beginning - while the ice keeps melting.
