In an Oxford lecture, the head of the British Antarctic Survey argues that leaders are failing to combat climate change, writes THERESA THOMPSON

In 1775, when Captain James Cook was prevented from reaching Antarctica by freezing fog and floating ice he decided there was probably not much to be gained from getting there. The world would derive no benefit from it.

How wrong he was. And one man who knows this better than most is Prof Chris Rapley CBE, Director of the British Antarctic Survey (BAS), who was in Oxford last week at the Said Business School for the second annual Oxford Earthwatch lecture. Its title: Absent Leadership and Shrinking Ice: How They are Connected and What to Do.

In a controversial lecture confronting the problems that we are facing, we, the inhabitants of earth, a finite place where, as Prof Rapley said, there's no user's manual, no spares, and no second chances, he cited the failure of governments worldwide to take sufficient action in the face of the global warming crisis.

Reminding us how much how the planet works as an integrated whole, he issued warnings about human kind's "energy addiction", a dependence driven by technology as we shifted from an "organic era" where energy came from beasts, slaves, and natural forces, to one where it comes from fossil fuels. While the former type of energy is a constant flow, the latter is a finite stock.

He argued that if human kind is to reduce this dependence on cheap, transportable, high-density energy from fossil fuels, new forms of leadership will be required.

"Leadership has so far been either absent or inadequate," he continued, adding that over the last five years, in spite of much rhetoric, the world's carbon emissions have continued to increase with no sign of our following a course that would limit global warming to levels considered acceptable.

Expressing his concerns about the sort of schemes most governments are adopting, he said there is a limit to what can be gained from carbon sequestration and trading. What matters is the amount of carbon we extract from the ground - locked up as coal, gas, oil - and released into the atmosphere - in the first place.

"It needs to be regulated if we are truly going to protect future generations. The best thing to do is what we did with CFCs," he argued.

Twenty years ago CFCs - chlorofluorocarbons, the man-made gases that caused a hole in the ozone layer over the Antarctic, discovered by BAS scientists in 1985 - provided a startling demonstration that earth functions as a complex whole. Scientists urged nations to control the use of CFCs and, by 1987, an international agreement saw countries phasing out their use to protect the ozone layer. Effectively, CFCs were made illegal.

"Carbon needs the same approach. Not banned, regulated," said Prof Rapley. "Better to keep carbon in the ground and regulate extraction. But you won't find many leaders who are willing to talk bout that."

Levels of carbon emissions are at six gigatons a year. Warning that we must learn to emit no more than two gigatons a year, he added that if we continue as business as usual, levels will rise to 16 gigatons by 2060.

Although CFC emissions around the developed world largely ceased after regulation, the damage to the stratospheric ozone layer continues even today, though it is diminishing. It would be the same for carbon. Even if emissions were stabilised instantly, we would have 0.1C temperature increases for decades, plus sea level rises as a result of greenhouse gases already emitted.

Prof Rapley has a long career of gathering climate change evidence. His first degree, in physics, was from Jesus College, Oxford University. He has worked on had an extended period leading UCL's space science laboratory, and also worked as Principal Investigator on NASA and European space prgrammes, and Agency satellite missions; most recently he has been involved in planning International Polar Year 2007-2008.

His biggest concern is rising sea levels, he said: "All the evidence from the past shows that a warmer world has higher sea levels."

Sea levels rise because as ice melts into water it warms and expands in volume. Ice sheets in Greenland and the Antarctic, built up over thousands of years, add to the problem once they melt and enter the sea.

Glaciologists are shocked, Prof Rapley said, by the rate at which ice is moving towards the sea and breaking up. Evidently, the Antarctic ice sheets are melting in response to warming rather more quickly than thought.

The facts are alarming: the temperature in West Antarctica is rising by almost four times the global average, the ocean below Antarctica is warming, there have been successive collapses of ice shelves - one, the size of Belgium, shattered in 2002 "like a car windscreen" - and these in turn seem to speed the rate at which ice on adjacent land is moving. But, how much ice could go and how quickly has yet to be answered.

"This melting could ultimately drain enough ice to raise sea levels by 1.5 metres," Prof Rapley warned, changing the world's coastline, displacing millions of people and disrupting critical infrastructure.

But he said there is cause for hope. People are trying to address the issues of climate change as never before and a combination of changed attitudes, behaviour and new technology can solve the problem.

What it needs, however, is a clear vision, a credible plan, integrity - in short, unprecedented global leadership.

Prof Rapley said: "105 years ago, Captain Scott turned back during his sled journey in Antarctica." We too have a long way to go, a lot to learn. Turning back is not a choice. We have to adapt to committed changes - and the reality will be painful but the longer we leave it, the harder it becomes. Then, he offered encouragement, Quoting John F. Kennedy, he said: "Our problems are man-made, therefore they can be solved by man."

Finally, in anticipating the Government's draft Climate Change Bill this week, Prof Rapley said: "How exactly does the Government imagine we are going to achieve the 60 per cent reduction by 2050?"

The Environment Secretary, David Miliband, has unveiled a Bill which has four main pillars: sets a carbon budget every five years, creates a committee of experts to advise the Government on the economic impact of carbon, sets up a system of annual reporting to Parliament on progress, and will include enabling powers to set up carbon trading schemes.