China threat over EU airline emissions trading
China is threatening legal action against the European Union for the emissions trading scheme (ETS) it is planning to introduce to airlines next year.
"I believe we have to take legal action," said Wei Zhenzhong, head of the China Air Transport Association.
Under the scheme, international airlines will have to pay for their carbon emissions in flights to Europe.
The head of Airbus has warned that the measure could lead to a trade war.
In a letter to EU climate commissioner Connie Hedegaard, Tom Enders said it was "madness to risk retaliation".
But Ms Hedegaard said the EU would stand up to any threats.
"When some parties start to threaten specific European companies, I think Europe should be very firm," she said.
Other industry figures have also opposed the Emissions Trading Scheme (ETS).
"We are now perhaps the highest taxed entity of any business on the planet today," said Tim Clarke, president of Emirates airline.
"The answer to this is obviously to get a global system. The problem with that is that it is long and slow to get to the end game, which is to see a reduction in carbon emissions."
US industry group Air Transport Association of America is also challenging the ETS in EU courts.
Non-EU airlines will be able to negotiate an exemption from the scheme if they can demonstrate that they are from a country with an equivalent emissions scheme.
"The last thing that we want to see is a trade war," said Giovanni Bisignani, head of the International Air Transport Association, adding that the EU had to heed a "growing chorus of countries strongly opposing an illegal extraterritorial scheme".