BRUSSELS — The European Commission said Monday that it would continue charging airlines for their greenhouse gas emissions, despite an announcement from China that its carriers would be forbidden to pay without its permission.
The E.U. program, which began Jan. 1, requires airlines to account for all emissions on flights using European airports and represents the Union’s boldest move to protect the environment.
Europe says its system is less costly than portrayed and would speed up the adoption of greener technologies at a time when air traffic, which represents about 3 percent of global carbon dioxide emissions, is growing much faster than gains in efficiency.
Earlier Monday, the Chinese air regulator effectively prohibited the country’s carriers from paying those charges or other fees, or increasing ticket prices in response to the E.U. system, without permission from the government.
The Chinese government said it was also considering unspecified measures to protect Chinese companies, something Europe can ill afford as it looks to China to help ease its debt crisis. European countries also want access to China’s fast-growing economy, including free-spending Chinese tourists who might not show up.
The intensifying dispute is another sign that European environmental regulations could lead to a trade war if governments start retaliating against carriers or products.
Much is at stake for Europe, which has sought to improve its international stature by spearheading initiatives on climate protection, including folding aviation into the Union’s six-year-old Emissions Trading System, in which polluters can buy and sell a limited quantity of permits, each representing a ton of carbon dioxide.
But making airlines account for flights that begin or end in faraway cities like Beijing has turned the system into one of the most contested environmental initiatives ever undertaken.
Airbus, the European aircraft maker, has already raised concerns that a trade conflict over the law could affect its businesses, and on Monday, Antony Tyler, the director general of the International Air Transport Association, a body representing the global airline industry, warned that some airlines could face a backlash.
“We’re concerned also about retaliatory measures taken by non-E.U. governments against E.U. carriers,” Mr. Tyler said. That was “an increasingly possible outcome,” he said, since the United States, China, India and Russia could discuss such steps at a meeting in Moscow on Feb. 21.
In the United States, the House of Representatives approved a bill last year that would ban U.S. air carriers from participating in the system. A similar bill has been introduced in the Senate.
The first payments by the airlines are due in early 2013, covering emissions from 2012. That still could leave time for the Europeans and foreign governments and airlines to reach a compromise, perhaps through the International Civil Aviation Organization, or I.C.A.O., an arm of the United Nations.
In the past, Europeans have strongly criticized the I.C.A.O. for dragging its heels on establishing standards and targets for greenhouse gases from aviation, a responsibility it was given under the Kyoto climate treaty 15 years ago.
But if the member countries of the I.C.A.O. significantly step up action to create a global system, the Europeans could relax, or even drop their system, and still save face.
Mr. Tyler, the head of the airline association, said Europe’s decision to unilaterally introduce its system had already pushed the I.C.A.O. to take a more urgent approach.
“Europe can take credit for that,” Mr. Tyler said.
For the moment, there is unlikely to be any immediate disruption to flights between Europe and China, or Europe and the United States, or penalties for Chinese and American airlines.
But airlines soon could be in a legal limbo, where their governments prohibit them from participating, but where they also risk breaking European law by refusing to pay.
Last month, the commission warned that airlines that flouted the law would face steep fines and then could face being banned from European airports.
In fact, many airlines probably will face little pain to begin with, and some may even profit.
Airlines will receive about 85 percent of their permits at no charge, to make it affordable for the carriers and their passengers to bear the cost of the system while the industry develops ways of cutting pollution.
Chinese airlines are among those that have applied for their free allocation.
Most airlines are expected to pass along the costs of the permits they buy — as well as the ones they receive free — by charging passengers a bit more for their tickets.
“The savviest airlines are figuring out that it makes sense to participate,” said Annie Petsonk, the international counsel for the Environmental Defense Fund, an environmental organization that favors carbon trading as a means to reduce emissions.
Last month, Delta added a $3 surcharge on fares to Europe in response to the system, and U.S. Airways and American Airlines have taken similar measures.
The added revenue from those charges could enable the airlines to buy the credits they need in advance while the prices of permits are low because of the weak economy, and to sell any surplus at a profit if prices recover, Ms. Petsonk said.
According to E.U. officials, the maximum increase in the price of a ticket between Europe and China should be less than €2, or $2.60, far less than the amount that many passengers routinely pay in the form of airport taxes in many countries.
The bigger worry for airlines is that they are looking at the thin end of an enormous wedge. The sums charged by the Europeans for permits could grow substantially in coming years if governments decide to auction a larger proportion of permits and if demand for the permits rises.
Mr. Tyler, the head of the airline association, conceded that some airlines that had cut capacity in recent years might be able to make money from the system.
But he said that the majority of airlines had grown capacity significantly since the European Union made its calculations about the volume of emissions and that, over all, the airlines would face costs of $1.2 billion in 2012 to pay for permits, rising to $3.6 billion in 2020.