Experts clash over volcanic ash

The inadequacy of technology to provide definitive answers about the threat of volcanic ash has become a central concern for scientists as authorities step up efforts to restore air travel.

Ash clouds from Iceland’s Eyjafjallajoekull volcano have been floating across most of northern and central Europe over the past five days with all non-emergency flights prohibited from leaving or entering UK airspace until at least 1300hrs tomorrow.

But EU transport ministers are only now holding emergency talks by video conference on how to ease the air travel crisis.

The International Air Transport Association has criticised the way European authorities have handled the situation so far, saying that it is ‘incredible’ that Europe’s transport ministers have taken so long to organise a teleconference.

Giovanni Bisignani, IATA’s director general, said: ‘We are far enough into this crisis to express our dissatisfaction on how governments have managed it - with no risk assessment, no consultation, no coordination, and no leadership.’

Leading airlines, who claim to be losing more than £130m a day as a result of the disruptions, are urging the civil aviation authorities to open the skies after having conducted trials of their own.

The problem centres around the fact that there is no way to accurately model ash plumes and understand what level of ash is safe to fly through. So far, it appears much of the decisions being made have been based on scientific guesswork.

Dr Craig Underwood from Surrey University said: ‘Aircraft routinely carry radar to check for weather but the trouble is the particles of ash are too fine for the radars to detect so pilots can find themselves suddenly in a plume without any warning.’

‘There is no known safe level of ash to fly through,’ he added: ’It’s all about the level of risk you want to take. Perhaps it would be possible to fly in some parts of it but you just don’t know what the density and the effects will be.’

The COBRA civil contingencies committee of UK cabinet ministers is also in meetings today to consider the situation. Reports so far suggest that Gordon Brown will be sending three Royal Navy ships to bring stranded Britons home from Spain.