Air transport associations and 21 airlines from home and abroad expressed strong opposition at a seminar on Monday against an EU plan to force countries into its Emissions Trading Scheme (ETS).

Starting Jan 1, all airlines flying to Europe will be required by the EU to be included in the ETS, a system that compels polluters to buy permits for each ton of carbon dioxide they emit above a certain cap. Those who do not join the system will face fines and flight suspensions.

Airlines said that they are required to buy permits for emissions released over the whole flight, only a small percentage of which may actually be in EU airspace.

Nancy Young, vice-president of environmental affairs with the Air Transport Association of America, said their monitoring results showed less than 9 percent of emissions from a flight from San Francisco to London take place in EU airspace.

Some 29 percent of the emissions take place in US airspace, 37 percent in Canadian airspace, and 25 percent over the high seas, she told the seminar.

Hosted by the China Air Transport Association, the seminar was attended by eight mainland airlines and 13 overseas carriers including American Airlines, Delta Airlines, United Airlines, All Nippon Airways, Singapore Airlines, Qantas, as well as one from Africa, one from the Hong Kong Special Administrative Region and two from Taiwan.

The imposed tax is more than just "inappropriate", said Zhang Baojian, regional vice-president of International Air Transport Association North Asia.

"The EU ETS is illegal," he said.

Though the ETS plan is part of the EU's climate policy, it is not helping emission reductions at all, and could be counterproductive, airline delegates said.

Mark Watson, head of environmental affairs with Cathay Pacific, said the EU ETS penalizes non-stop long-haul flights, which are more fuel-efficient than flights with intermediate stops.

For example, a Hong Kong to London non-stop flight is 16 percent shorter and will emit less carbon dioxide. But it will attract an additional 76 percent charge than a flight from Hong Kong to London routed via an intermediary stop in the Middle East, because only the second leg from the Middle East to London will attract a carbon charge, he said.

In addition, the EU has not guaranteed the revenues generated by the sale of carbon trading permits will be directed to environmental or climate change projects. It means individual EU member states will be able to generate additional revenues from aviation, he said.

A good example, Watson said, is in the United Kingdom where departing passengers pay Air Passenger Duty, which was established as an environmental tax but is used to swell the general taxation pot, he said.

Australia, New Zealand and Japan are also mulling over schemes to charge airlines for emitting CO2 in their airspace.

Airlines are likely to be charged more than once for the same CO2 emissions, and the cost will eventually be passed on to passengers.

"We are not in denial about climate change and we are serious about tackling our environmental responsibilities Our emission must be regulated - but this needs to be done at a global level through the implementation of a global approach," Watson said.