A chimney is seen framed in the background by devices for collecting samples of Beijing's air, which are installed on the rooftop of the air quality forecast and warning center, in Beijing, China, May 21, 2015. Beijing's city government organized a media tour on Thursday to its environmental protection monitoring center and a gas-fired thermoelectricity power plant to showcase its efforts to promote clean energy transformation. (Photo by Kim Kyung-Hoon/Reuters)
