China recently announced that it would join the International Renewable Energy Agency. China is a global leader in terms of installed capacity and investment in clean energy, though the acknowledgement of its status may come as a surprise to some, given the recent headlines on the country's air pollution. But in 2012, China invested $68 billion to develop renewable energies, 55 percent more than US investments, making it the largest clean energy investor in the world.

What is important for energy sustainability, however, is not only the scale of clean energy products and the amount of investment, but also the environmentally friendly approach through which the sector is built and operated. Although clean energy is certainly not to blame for a large part of the pollution problems, China's efforts to rapidly develop renewable energy have generated some environmental problems.

The lack of effective environmental policymaking and regulation has led to unsustainable practices in China's renewable energy sector that have cast a shadow on the country's "top spot" numbers.