Mr Pugh's 1,200km journey is due to begin from the Norwegian island of Spitsbergen on 29 August. The lawyer, 37, of Russell Square said: "We have lost more than half the Arctic summer sea ice cover decades ahead of predictions, showing climate change has been hugely underestimated. We must insist our leaders take urgent action. Although sea ice is melting fast, I sincerely hope there is more than predicted and it is impossible for me to kayak all the way."