DESPITE hostility from many foreign governments and airlines the European Union last month went ahead and introduced a requirement for airlines to buy permits to cover the carbon-dioxide emissions of all flights into and out of European airports, including the portion of those flights that is outside EU airspace. China was one of the states most vehemently opposed to Europe's unilateral imposition of this "carbon tax" and today the Chinese official news agency Xinhua said the government had banned the country's airlines both from buying permits and from adding supplements to their ticket prices to cover their cost. In theory the EU could now ban Chinese airlines from European airspace, possibly triggering a horrendous global trade war. But in practice the airlines have until early next year to account for this year's emissions, so there is still plenty of time for negotiation. It will be interesting to see who blinks first. 

No doubt the Chinese airlines will in public uphold the party line, and continue to protest at being included in Europe's emissions-trading scheme (ETS). However, they may privately be looking with envy at the rest of the world's carriers, which are free to start adding ETS surcharges to their ticket prices. To explain why, here are some rough calculations that Andrew Charlton of Aviation Advocacy, a consultancy, has made about Ryanair's new ETS supplement of 25 euro-cents per passenger per flight.

In the first year of their inclusion in the ETS, airlines will be given 85% of the carbon permits they need, and only have to buy the remaining 15%; in subsequent years the proportion of free permits will fall to 82%. Ireland's environment agency has announced that Ryanair will receive just under 5.6m permits; since these must represent 85% of its needs, it therefore must need to buy about 980,000 further permits, equivalent to the balance of 15%. At the moment the permits are trading at just under €8 ($10.5) each, but Mr Charlton supposes that their price might go up to, say, €8.50. If so, the cost to Ryanair for this year's permits will be €8.3m. Last year the airline flew 76m passengers. Supposing it flies at least as many this year (indeed its passenger numbers are likely to grow), that 25-cent charge will rake in at least €19.1m, which means that Ryanair will enjoy a profit of at least €10.8m from the supplement after buying the permits. When the airline announced the extra charge its communications chief, Stephen McNamara, said the ETS permits would cost it €15m-20m a year. But this seems to be the cost of buying 100% of them, not the 15% that the airline has in practice to pay for.

This further demonstration of Ryanair's ingenuity in finding new ways to supplement its revenue is bound to delight its admirers among Europe's travelling public. It will surely inspire other carriers to follow suit: the airline business barely scrapes a profit at the best of times, so any means of squeezing a little bit extra out of passengers while blaming governments is more than welcome. 

Mr Charlton says no one from Ryanair has yet challenged his sums. We'd love to hear from the airline if only it published some means of contacting its press office. So if you're reading this, Mr McNamara, and want to reply, write to