The inconclusiveness of the Poznan talks last weekend signals once again that our leaders are prepared to drink in the last chance saloon - with last orders being called (Global climate change decisions on hold for Obama, 15 December). There is just a year left for our political leaders to put a post-2012 deal in place at Copenhagen next year, if there is to be any hope of preventing global warming from reaching really dangerous levels. But slow progress seems to signal a deal that will fall short of expectations.

Scientists have presented a barrage of evidence for global warming and I have seen with my own eyes the irrevocable changes taking place in the Arctic Ocean. Each year more and more of the fragile multi-year sea ice melts and it could be less than a generation before the ice cap disappears completely. The loss of this astonishingly beautiful place will be a tragedy in itself, but a still greater calamity for us all is its unbalancing of the Earth's whole eco-system.

Next year, during the critical few months before Copenhagen, I will be leading a scientific expedition to the north pole to assess the status of the ice. Using a specially designed ice-penetrating radar, the Catlin Arctic Survey team will take millions of readings of the thickness of the floating ice over a 1,200-kilometre route. The data will be analysed by the world's leading scientists from organisations including Nasa.

I believe I owe it to my children and future generations to carry out this important, if hazardous, survey. Putting our abilities as explorers at the disposal of climate scientists is our team's small contribution to securing a solution. It is to be hoped world leaders recognise early enough they have a still greater role to play in Copenhagen next year.

Pen Hadow

Catlin Arctic Survey