The European Union's proposed "carbon border tax" on imports could introduce uncertain and harmful factors to otherwise friendly cooperation in climate talks, an adviser to China's negotiating team at a United Nations conference said on Wednesday.
The EU's senior climate official said in October the newly installed European Commision would push for a tax to account for carbon emissions of foreign firms. Such a tax would likely raise the price of Chinese products in Europe.
That could trip up talks underway in Madrid to settle the final items of the Paris Agreement before it enters an implementation phase next year, when countries are set to unveil more ambitious targets for cutting greenhouse gases.
The tax would run counter to the Paris accord which is founded on multilateralism and countries' voluntary participating, said He Jiankun, a professor at Tsinghua University who is travelling with China's official delegation.
"If this carbon tax is unilaterally instituted, it could bring uncertain and some harmful factors to the process," he told reporters, stressing it was his personal opinion.
"Currently adopting this type of cross-border measure could influence the friendly atmosphere of cooperation in the process of confronting climate change."
Last week, China issued a report saying the tax would seriously harm global efforts on climate change.
At the time, Zhao Yingmin, China's vice minister of environment, said that unilateralism and protectionism should not be allowed to hurt the will of countries to jointly tackle climate change. Zhao is the ranking member of China's negotiations team at the climate talks.
The tax is part of the European Green Deal, the signature environmental policy of the new European Commision, and aims to protect European firms from unfair competition by raising the cost of products from countries taking inadequate action on climate change.