On World Environment Day, which falls on Wednesday, European environmentalists and clean-tech leaders are campaigning a stone's throw away from the European Union headquarters to expand the use of solar power and other alternative energy sources.

However, in the building nearby EU trade officials will most likely be choosing to slam the door on China's multibillion-dollar exports of competitive solar products by exerting an average 47 percent of anti-dumping tariffs on China's solar panel producers.

It is a decision that could trigger a trade war and damage EU-China relations at a time when Beijing's new leadership is seeking to further boost the so-called strategic partnership.