Cooperation on climate change has been a bright spot in China-US relations in recent years. The two nations have cooperated extensively, from their Climate Change Working Group and Clean Energy Research Center to programs on heavy-duty trucks, electric cars, smart grids, smart and low-carbon cities, energy efficient buildings and industry, carbon capture use and storage and nuclear energy cooperation. The list is both long and expanding.

While China, still a developing nation, has shown leadership in the global efforts to fight climate change, the Obama administration also deserves credit for its resolve, especially given the strong opposition it has faced from the US Congress.

There is one contradiction, though, the Obama administration's protectionist trade policy on renewable energy. Over the past years, the US government has imposed stiff punitive anti-dumping and countervailing duties on solar and wind products from China. The World Trade Organization judged last year that some of the US countervailing duties were set too high, yet many punitive US measures still pose a threat to Chinese solar and wind power companies while at the same time increasing the cost for US consumers, who have to pay more than people in many other countries to access solar and wind energy.

The protectionism at the expense of the climate and environmental cause has drawn sharp criticism from environmental groups not just in China and the US, but also globally.

I still remember back in 2010 when then New York Mayor Michael Bloomberg attended a meeting on climate change and environment in the Hong Kong Special Administrative Region, and called on Americans to stop blaming China for their own problems. "Let me get this straight: There's a country on the other side of the world that is taking their taxpayers' dollars, and trying to sell subsidized things so we can buy them cheaply, and have better products, and we're going to criticize that?" asked Bloomberg, who is now UN Secretary General's special envoy for cities and climate change and was selected this week to lead a global task force on climate change.

As world leaders race to reach a climate deal in Paris on Friday, Obama wants the deal to become a key legacy of his eight-year presidency. However, his protectionist policy that undermines China's renewable industry and the climate cause will tarnish this legacy.

The author is deputy editor of China Daily USA. chenweihua@chinadailyusa.com