Newsnight's Susan Watts joins a team of scientists travelling to the Arctic to carry out crucial climate research.
By Susan Watts
BBC Newsnight, science editor
The email arrived one Saturday morning. Out of the blue, the chance to join an Arctic research expedition for the Summer.
Over the next few weeks, the Scottish Association of Marine Sciences (SAMS) will be taking a detailed scientific snapshot of life in the Arctic Ocean - on board the UK's famous Arctic research vessel - the James Clark Ross. And Newsnight's going with them.
Dr Jeremy Wilkinson explains to Susan Watts awhat has been happening to the sea ice in the Arctic and what may happen in the future.
The scientists' mission: to investigate the tiny life forms that live in the icy Arctic waters, and hopefully to gain a better understanding of the effects of climate change.
OK, phytoplankton might not be the first thing you think of when you think of the Arctic - that's probably ice - but this microscopic sea life is vital, not only to the future of life in the Arctic, but perhaps all life on the planet.
As Ray Leakey, chief scientist for the expedition, puts it: "The Arctic is getting warmer - it's the fastest warming part of the planet. The melting of the sea ice affects not only the physical system, but also the plants and animals.
"So this research cruise will investigate how the eco-system responds to a warming Arctic, and hopefully give us an insight into what might happen in the other oceans."
Dr Raymond Leakey tells Newsnight's Susan Watts about what they will see in the Arctic.
Filmed at their base at the Scottish Association for Marine Science - or SAMS in Oban.
Phytoplankton, sometimes referred to as microalgae, sit at the bottom of the food webs that branch through shrimp-like creatures, or zooplankton, and up to fish, then seals and eventually to the polar bears that call the Arctic their home.
Take away the phytoplankton, and you put everything higher up at risk. More than that, what happens to phytoplankton at the poles will help scientists to predict what might happen to the types of phytoplankton that live in warmer oceans. In a warmer world, the polar seas heat up first.
So they are a laboratory, or test bed, for the rest of the world.
Ray and his team want to find out how well phytoplankton can adapt to this warmer world. Will they flourish or flounder? And what might this mean for their cousins in warmer oceans?
Navigation Officer Douglas Leask tells Newsnight's Ming Tsang where the James Clark Ross is heading.
Because the startling fact is that the oceans - or more correctly, the life forms that live in them, account for about half of all the absorption by the planet of the carbon dioxide that circulates through the atmosphere. If we disturb that so-called carbon "sink", then the world could be in big trouble.
The oceans' carbon cycle goes something like this. The phytoplankton take in carbon from the atmosphere to survive. They're eaten by microbes and zooplankton (like algae, but animals) - which give out CO2.
The phytoplankton and the animals that feed on them die, which locks carbon away in a stable form on the ocean floor.
Scientists suspect that warming the Arctic Ocean, and melting the ice above it so that more light filters through, will make life quite pleasant for many phytoplankton.
But it's not straight forward. More phytoplankton might grow, but they might not be the right kind for the zooplankton to eat.
In the Arctic Ocean, two oceans collide - the salty, relatively balmy Atlantic, and the icy, fresh water of the Arctic itself.
As the water at this collision zone becomes warmer, scientists aren't sure which type of phytoplankton might thrive, those that normally prefer the Atlantic habitat, or those more comfortable in the Arctic mix. The shifting balance in these populations will affect the amount of carbon the ocean absorbs.
Another intriguing possibility is that the changing food web might mean an abundance of zooplankton and an abundance of fish.
The Arctic could even become the world's bread basket - as the Mediterranean and tropical seas warm so much that they become uninhabitable. We know from historical records that dramatic shifts in the life forms of an ocean can take place in just a few decades - a process that scientists refer to as "regime shift".
As Newsnight follows the cruise, three scientists - all from the SAMS home base in Oban on the west coast of Scotland, will blog day-by-day for the Newsnight website, keeping us up to date with the experiments, and life on board.
And then of course, there's the ice. Our research team could find themselves witnesses to a defining moment for the world. Early this month, newspaper headlines screamed an alarm for summer 2008.
The ice in the Arctic naturally thins outs every summer - with its lowest point in July and August each year. But 2007 saw the Arctic sea cover reach a record low.
All eyes are on the waters above Longyearbyen to see if the trend continues. If it does we the team may see a summer thinning of the Arctic ice so unprecedented that it disappears completely at the North Pole.
The SAMS "ice expert", Jeremy Wilkinson, told us that the daily satellite images of the ice cover look grim - though if he were forced to make a prediction he thinks it's too early to see zero ice at the North Pole.
But his look ahead is still pretty dire. Within just two decades, he believes, a North Pole with no ice at all could be the norm for the summer months.
George Pagliero, a documentary filmmaker, will join the mission for Newsnight for part of its journey, and producer Ming Tsang and I will join the ship for a few days on its way home at the end of August.
We'll join at the Ny Alesund polar research base on Svalbard - the same infamous Svalbard of Lyra's Golden Compass adventures from Philip Pullman's His Dark Materials trilogy. We'll travel with the team to Longyearbyen, the Arctic "tourist" destination where the mission ends.