Pen Hadow returns to Arctic to study acidification of the oceans

The explorer Pen Hadow is mounting a new expedition to the Arctic to research “climate change's evil twin” – the acidification of the oceans caused by emissions of carbon dioxide.

Click here to see a map of the expedition.

Starting next month, his team will face temperatures of minus 75 – when the wind chill factor is included – as well as frostbite, thin ice and polar bears, to sample sea water far out over the sea ice, as well as from a base in Arctic Canada. They will be seeking to measure how far soaring emissions of CO2 from industry and transport are turning the waters acidic – a phenomenon which may pose a serious danger for marine life.

It will be the second successive year that Mr Hadow, who in 2003 became the first man to walk unaccompanied to the North Pole, has led an Arctic expedition to investigate climate-related problems. Last year, in the Catlin Arctic Survey 2009, he headed a mission to map in detail the thinning of the floating sea ice with rising temperatures. The Catlin Arctic Survey 2010 will bring together marine biologists, oceanographers and explorers to investigate the impact of increased CO2 absorption by the seas.

Acidification, which occurs when CO2 reacts with water to produce carbonic acid, is believed in to threaten the marine food chain, by damaging organisms at its bottom which use calcium carbonate to build their shells or structures. As reported in today’s Independent, scientists at the American Association for the Advancement of Science meeting in San Diego said this week that if CO2 emissions continued on their present course, rising acidification would lead to all the world’s coral reefs beginning to disintegrate by the end of the century.

Global CO2 emissions, which were about 21bn tonnes in total in 1990, are something over 30bn tonnes annually now, and are thought to be rising at about two per cent per year.

The case of the Arctic Ocean is perhaps even more urgent, as the cold waters of higher latitudes absorb more CO2 than the warm waters of the tropics. "Hardly anyone goes to the Arctic Ocean – they don't see it, they don't experience it and, inevitably, the understanding is low on a global basis of what the Arctic Ocean is,” Pen Hadow said today. “It’s my view that never has there been a greater need for exploration if we are to understand how the natural world works.”

Six scientists will be among a group of 12 travelling to an “ice base” on Ellef Ringnes Island on the edge of the Artic Ocean to take water measurements, while others will be trekking out onto the sea ice itself.

In case of polar bear attack, Mr Hadow said the team would carry "bear bangers" – a kind of warning firework – but would also be armed. He added that although in his exploring career the had encountered polar bears between 20 and 30 times, he had never had to shoot one, and had only hurt one once, when a bear poked its head into its tent. “I hit it on the eyebrow with a saucepan, which made a Booing! noise,” he said. “The bear fled. I think it was as scared by the noise as much as by me hitting it.”