A worker maintains the green rooftop of a building at the Beijing University of Chinese Medicine in Beijing, capital of China, July 12, 2013. According to Beijing Rooftop Landscaping Association, the city's green rooftop area has expanded to more than 1.2 million square meters up to the end of 2012, one percent of the total area. Planted over waterproofing membrane, green roofs help reduce pressure on urban drainage system and boost buildings' insulation value. (Xinhua/Luo Xiaoguang)
The green rooftop of a building is seen at the Beijing University of Chinese Medicine in Beijing, capital of China, July 12, 2013. According to Beijing Rooftop Landscaping Association, the city's green rooftop area has expanded to more than 1.2 million square meters up to the end of 2012, one percent of the total area. Planted over waterproofing membrane, green roofs help reduce pressure on urban drainage system and boost buildings' insulation value. (Xinhua/Luo Xiaoguang)
Workers maintain the green rooftop of a building at the Beijing University of Chinese Medicine in Beijing, capital of China, July 12, 2013. According to Beijing Rooftop Landscaping Association, the city's green rooftop area has expanded to more than 1.2 million square meters up to the end of 2012, one percent of the total area. Planted over waterproofing membrane, green roofs help reduce pressure on urban drainage system and boost buildings' insulation value. (Xinhua/Luo Xiaoguang)
Ma Liya, a researcher specializing in rooftop greening, introduces carpet sedum (Sedum Lineare), an ideal plant for the greening of flat-roofed building, on the green rooftop of a building at the Beijing University of Chinese Medicine in Beijing, capital of China, July 12, 2013. According to Beijing Rooftop Landscaping Association, the city's green rooftop area has expanded to more than 1.2 million square meters up to the end of 2012, one percent of the total area. Planted over waterproofing membrane, green roofs help reduce pressure on urban drainage system and boost buildings' insulation value. (Xinhua/Luo Xiaoguang)
A butterfly flutters over the green rooftop of a building at the Beijing University of Chinese Medicine in Beijing, capital of China, July 12, 2013. According to Beijing Rooftop Landscaping Association, the city's green rooftop area has expanded to more than 1.2 million square meters up to the end of 2012, one percent of the total area. Planted over waterproofing membrane, green roofs help reduce pressure on urban drainage system and boost buildings' insulation value. (Xinhua/Luo Xiaoguang)
Green rooftops are seen at the Beijing Institute of Fashion Technology in Beijing, capital of China, July 12, 2013. According to Beijing Rooftop Landscaping Association, the city's green rooftop area has expanded to more than 1.2 million square meters up to the end of 2012, one percent of the total area. Planted over waterproofing membrane, green roofs help reduce pressure on urban drainage system and boost buildings' insulation value. (Xinhua/Luo Xiaoguang)
The green rooftop of a building is seen at the Beijing University of Chinese Medicine in Beijing, capital of China, July 12, 2013. According to Beijing Rooftop Landscaping Association, the city's green rooftop area has expanded to more than 1.2 million square meters up to the end of 2012, one percent of the total area. Planted over waterproofing membrane, green roofs help reduce pressure on urban drainage system and boost buildings' insulation value. (Xinhua/Luo Xiaoguang)
