Every year thousands of doctors and scientists fly to meetings all over the world, but with climate change accelerating, can this type of travel be justified, two doctors debate the issue in this week's BMJ.

Flying across continents in great numbers to exchange information will soon become as outdated and unsuitable to the modern world as the fax machine and the horse-drawn carriage, writes Professor Malcolm Green, from Imperial College, London.

Driving less and low energy light bulbs can contribute a little to reducing our carbon footprint, but if doctors stop going to international conferences they could make a real difference and be seen to be taking the lead, he argues.

In 2006, over 15 000 doctors and scientists from all over the world attended the American Thoracic Society meeting in the US. The flying delegates produced about 10 800 tonnes of carbon, representing 100 million person air miles. If you add in all the conferences all over the world this would equate to about 600 000 tonnes of carbon a year, says Green, and this is without including the energy costs of large hotels and enormous conference centres.

With the advent of teleconferencing, videoconferencing and other modern technologies there is no reason why doctors cannot attend virtual medical conferences, an already highly successful and common practice in organisations such as oil companies and financial institutions, he concludes.

But Professor James Owen Drife, from Leeds General Infirmary, argues that giving up medical conferences will have only a minuscule effect on global warming.

He points out that although people respect doctor's opinions on medical matters, this influence is unlikely to extend to persuading holidaymakers, who make up 60% of UK international travellers, to stop attending football matches or tropical weddings.

He argues that conferences are essential for inspiring and motivating and can even stimulate global action—would the 1964 Declaration of Helsinki have had as much effect on research ethics if it had been a group email, he asks.

In the 1980s the internet was heralded as the replacement to such meetings, in the 1990s it was electronic conferences, and last year, "Facebook for science" appeared, but nothing, he says, can or has replaced genuine communication.

Although Drife believes doctors should continue to attend medical conferences he accepts a compromise is essential. For instance, delegates should be urged to visit and learn from local populations and there should be a networking facility to prevent conferences on the same topic being offered back to back in different continents.

But, he concludes, "hiding behind our computer screens and pretending that this is helping the planet" is not a realistic option.