We were homeward bound one night on the deep
Swinging in my hammock I fell asleep
I dreamed a dream and I thought it true
Concerning Franklin and his gallant crew.
With 100 seamen he sailed away
To the frozen ocean in the month of May
To seek a passage around the pole
Where we poor sailors do sometimes go.
On a wall of the chapel of St John the Evangelist situated inside Westminster Abbey is set a white marble bust of a man dressed in naval uniform, his gaze fixed on some unknown horizon. Beneath it are some lines of verse, specially written by Tennyson, which read: "O ye frost and cold, O ye ice and snow, Bless ye the Lord: praise him and magnify him forever."
The statue is that of Sir John Franklin, one of Britain's most famed and celebrated explorers, yet a man who is best known for what he ultimately failed to discover: the Northwest Passage. Franklin died in 1847 while desperately searching for this fabled route - a way for commercial shipping through the Arctic sea ice and a short cut from the Atlantic Ocean to the treasures of the Pacific that avoided the vast and perilous journey around Cape Horn.
To this day the remains of Franklin and most members of his 129-strong crew have never been recovered. The bust in Westminster Abbey was erected by his wife, Lady Jane Franklin who commissioned several of the 20 or so Arctic expeditions sent to try and find out what happened to her husband. She, too, was the author of the words to "Franklin's Lament", a song made popular in the Sixties by the folk singer Martin Carthy.
Though Franklin never discovered a route through the Arctic waters - the winter sea ice stranding him and his two ships HMS Erebus and HMS Terror - something remarkable is now happening in those previously hard-frozen wastes where he and his men lost their lives. Warming sea temperatures and retreating sea ice mean the almost mythical Passage could soon become a reality for mariners.
Some believe that within as little as a decade or two, ships from Europe could be regularly travelling to the Pacific through this new route, avoiding the Panama Canal and cutting up to 6,000 miles - and the resultant time and fuel costs - from their journeys. Other already existing sea routes, such as the so-called Arctic Bridge between Canada and Russia, are likely to be operational for a longer part of the year.
The implications of this are enormous. Already a number of countries are scrambling to ensure they are ready to reap the benefits from what may be the most significant maritime development in centuries. Nations such as Russia, the US and Canada are fighting to protect their claims to Arctic waters while regional authorities and corporations are spending millions of dollars developing new infrastructure in some of the world's most barren and forgotten sea ports as they anticipate a gold rush.
"It's the positive side of global warming, if there is a positive side," said Ron Lemieux, the transportation minister of Manitoba, the Canadian province that is investing millions of dollars developing the infrastructure surrounding Churchill, a once decaying port on the Hudson Bay. "We have seen the potential for the Arctic ports. As we see it, Manitoba has always been a gateway to North America or Europe. We see it becoming a gateway to the world."
The port of Churchill, actually owned by a far-sighted US businessman who bought it for a token C$10 (£4) from the Canadian government in 1997, is just one of many Arctic ports and cities that are likely to see a boom in the years ahead as companies and governments seek to make use of the retreating ice to develop new fishing grounds, previously out-of-reach oil and gas resources and even new destinations for cruise liners. The man who owns Churchill, Pat Broe, told The New York Times he believes the port could make $100m a year. He has already spent $50m upgrading the port, whose season as a destination port as part of the Arctic Bridge, he believes, could grow to 10 months of the year from its current four.
Indeed, in all of the five Arctic nations that have borders with the Arctic Ocean - Canada, Denmark, Norway, Russia and the US - preparations have already started to benefit from the changes. Authorities in the Russian port of Murmansk, the largest city within the Arctic circle, likewise anticipate a turnaround in their fortunes.
All of this is happening because of the rapid shift in polar geography taking place due to global warming. Earlier this year it was reported that for the second winter in consecutive years, Arctic sea ice had failed to reform after summer melting. There are fears that "positive feedback" may have already started and that the melting ice itself causes the seas to warm further as more sunlight is absorbed by a dark ocean rather than being reflected by white ice.
Mark Serreze, a sea-ice specialist at the US National Snow and Ice Data Center in Colorado, said: "In September 2005, the Arctic sea-ice cover was at its lowest extent since satellite monitoring began in 1979, and probably the lowest in the past 100 years." Traditionally, sea ice in the Arctic, which floats on the ocean surface, normally covers an area of around 2.4m square miles - or the size of Australia - during the month of September. Satellite images taken in September 2005 showed a reduction of around 20 per cent from the long-term average.
In 2004 the Arctic Climate Impact Assessment (ICIA) said Alaska, western Canada and eastern Russia, had experienced an increase in average winter temperatures of as much as 4C in the past 50 years. Within the next 100 years temperatures are projected to increase by a further 7C. By the year 2070 it is estimated that Arctic polar ice will only cover a fraction of the area it currently does.
In the Arctic region, where the effects of global warming are intensified, the physical evidence of this change are obvious. Glaciers are in rapid retreat, permafrost is melting, causing buildings to subside and tumble, voracious beetles that previously could not live in the Arctic climate are now stripping forests bare. Sea ice is forming later in the year and less solidly, offering less protection to the land from the erosive powers of the sea.
Last September, when experts recorded the lowest ice coverage on record, I travelled to the Alaskan coastal town of Barrow, the most northerly community in the US and past which ships travelling through the Northwest Passage would journey. There, senior members of the Inupiat community said that they had been aware of the change in the climate for the past 20 years - before the scientists instruments had detected the shift.
At that time the sea ice should have been fixed in hard rigid sheets stretching towards the North Pole; instead it was forming far out at sea, 100 miles from the shore. "We have been saying this for a number of years," said Eugene Brower, the local fire chief and captain of a whaler. "In the Fall, it takes longer for the ocean to freeze. By now there should be ice here."
The broader implications of this ice melt are extraordinary and the scale is difficult to put measure to. Scientists have warned that the geography of the world's landmass could change as low-lying areas flood, that entire habitats could change and the lives of many millions of people living in some of the most vulnerable places in the world could be threatened.
How different the situation was when Franklin journeyed to the Arctic. He had first travelled to the region in 1818 and became fascinated by it, even though his subsequent expeditions there were considered unsuccessful. By the time he set sail on what would be his final Arctic expedition in May 1845, he had served for six years as Governor of Tasmania and at the age of 59 was essentially considered a man whose career had run its course.
Nevertheless, when Franklin and his crew set sail - his instructions from the Admiralty to travel to Baffin Bay, thence to Lancaster Sound and from there through the Bering Strait - this greying mariner had captured the imagination of at least some of the citizenry. The Times reported of his departure: "There appears to be but one wish amongst the whole of the inhabitants of this country, from the humblest individual to the highest in the realm, that the enterprise in which the officers and crew are about to be engaged may be attended with success and that the brave seamen employed in the undertaking may return with honour and health to their native land."
There are many accounts of the fate that was to befall Franklin and his men. One of the most detailed, Frozen in Time by Owen Beattie and John Geiger, argues that the expedition was beset by two overwhelming factors - lead poisoning caused by the lead used in the sealed cans in which they carried much of their supplies and harsh weather which for two subsequent winters froze solid the channels through which they'd hoped to travel.
There was no news of the expedition for a full five years and then in 1850, an expedition dispatched from London discovered relics of the Franklin party on Beechey Island, along with the graves of three men. Subsequent expeditions discovered more details, including evidence that members of the party had resorted to cannibalism to try and survive. Finally, in 1859, yet another expedition discovered a note on King William Island, written by Franklin's second-in-command, which detailed what had happened to their leader.
Beattie and Geiger write: "Beset by pack-ice since September 1846, Franklin's two ships ought to have been freed during the brief summer of 1847, allowing them to continue their push to the western exit of the passage at the Bering Strait. Instead they remained frozen fast and had been forced to spend a second winter off King William Island. For the Franklin expedition this was the death warrant."
The search for the Northwest Passage had consumed mariners for centuries. As far back as 1539 Hernan Cortes ordered one of his officers to sail the length of what is now the Baja California peninsula in search of a route that the Spanish called the Strait of Anian. Thirty or so years later the explorer Martin Frobisher made three separate voyages into the Canadian Arctic in search of a route. He failed but was rewarded with a bay that is named after him. In 1609 Henry Hudson sailed up the river that is now named after him, also in a failed attempt to find the passage. Hudson Bay is also his legacy.
But it was the explorers of early 19th-century Britain that set about discovering the passage with perhaps the most dedication. In the aftermath of the defeat of Napoleon in 1815, Arctic exploration became seen as a suitable way of putting to work young officers. In addition to Franklin's own expeditions to the Arctic in 1818 and then a second shortly afterwards, exploration of parts of a passage were made by John Ross, William Edward Parry and James Clark Ross.
"The quest for the Northwest Passage was a holy grail of exploration. It was a glittering prize to be won, but it was partly a prestige thing," said Pieter van der Merwe, a historian at the National Maritime Museum in Greenwich. "The extent to which they thought this route would be commercially viable is difficult to determine. This was happening in the 1820s, after the French wars, when Britain had dominion over the seas. The Navy was full of testosterone-filled young men and they had to find occupations for them."
Yet despite the efforts of those British Victorian explorers, driven by a host of motivations including that of scientific discovery, the Northwest Passage would not be their prize. A route though the ice was not found until 1906, when the Norwegian explorer Roald Amundsen - the same man who would later beat Robert Falcon Scott to the South Pole - completed a three-year voyage that ended with a traverse of the Passage in a 47-ton fishing boat called Gjøa. His route was certainly not commercially viable - it had taken too long and parts of his route were extremely shallow - but it was undoubtedly an achievement.
Amundsen had been alerted of his success while in his cabin when the cry went up that another vessel was approaching them from the west. It meant they had cleared the route. "The North West Passage had been accomplished - my dream from childhood," he later wrote in a memoir of the journey. "This very moment it was fulfilled. I had a peculiar sensation in my throat. I was somewhat overworked and tired, and I suppose it was weakness on my part, but I could feel tears coming to my eyes. 'Vessel in sight!'. The words were magical."
Amundsen's achievement was no small feat. Indeed it would not be until 1957 that US Coast Guard cutters traversed a route through the Northwest Passage that could handle a deep draft vessel. It was this route that explorers - Franklin among them - had been searching for for almost 500 years.
Experts say it is unclear at exactly what pace the sea ice of the Arctic will continue to disappear. Some believe that those who say the Northwest Passage will be routinely ice-free within as little as two decades are likely to be proved wrong.
A recent paper by a group of ice experts from the Meteorological Service of Canada concluded that "predicting an ice-free Arctic by the middle of this century may lead many into a false sense of optimism regarding the ease of future shipping in the Canadian Arctic. Sea ice conditions are highly variable and there will still be summers of occasional heavy ice conditions. It is important to remember that with our present, imperfect ability to predict future impacts on Arctic sea ice there are a number of plausible climate change scenarios."
One of the report's authors, John Falkingham, based in Ottawa, told me that even if the ice continued to melt at the current rate his team believed that on the data collected over the last 40 years, the last ice in the Arctic would be in the Canadian Arctic. "The other thing I always caution about is the annual variability - we know that the ice can vary year to year."
He said given such uncertainties and that ships might put to sea only to discover themselves becoming trapped, owners might prefer to dispatch their vessels on a longer but guaranteed route. "We don't think in the near future there is going to be no ice. We're still going to see a lot of ice around."
While some experts warn of caution, governments are already moving quickly to respond to the new opportunities. Stephen Harper, who was elected last January as Canadian Prime Minister, had made the assertion of Arctic sovereignty one of his campaign issues. He vowed to spend more to ensure Canada's military presence in the region, including the construction of three armed icebreakers to be located at Iqaluit.
Indeed, one of Harper's first diplomatic battles as Prime Minister was with the US Ambassador to Canada who said Washington did not approve of Canada's plans to militarise the North and did not recognise its claims to Arctic waters of the Northwest Passage. He claimed, instead, that they were part of a free international shipping route. "The United States defends its sovereignty. The Canadian government will defend our sovereignty," Harper responded.
It is impossible to know what Franklin would have made of all this, whether he would have appreciated the irony of the Northwest Passage being conquered not as a result of man's dedication and effort, but as a result, ultimately, of man's failure to address global warming and to curb its addiction to fossil fuels.
Certainly, one of his descendants is very concerned about the rapid changes happening to the planet. Adrian Gell, related to Franklin because "his only daughter from his first marriage, married my great, great grandfather", says he fears change may be happening too fast, that as a society we need to act more cautiously. Gell, who has studied the life and expeditions of his celebrated ancestor, is also concerned that Franklin's reputation has suffered recently from revisionists who have portrayed him "as a fool".
"This man had the opportunity to explore uncharted areas. He went there and died in the process, effectively having discovered that route," Gell told me. "He has been poo-poohed and it's been said he should not be a hero."
"I feel," he added, "that the world is moving at a rather frightening speed and, in a way, that man has been staggeringly careless."