China’s rapid development over the past three decades has lifted hundreds of millions of people out of poverty and catapulted the country into the ranks of the world’s largest economies. Over the next several decades, as China’s economy continues to grow and the pace of urbanization accelerates, the country must not only ensure that it has sufficient and secure energy resources but also mitigate the impact such growth will have on the environment.

China must address these issues without compromising its growth or the living standards of its people. But the population’s huge size and the scale of the economy have created a uniquely challenging problem. To deal with it, China’s policy makers have developed an extensive body of regulations and policies to raise the energy efficiency of many sectors and thereby reduce growth’s environmental consequences, including carbon emissions.

To help policy makers and business leaders identify and prioritize additional opportunities to raise energy efficiency in China and make its growth more sustainable, we undertook a study of technologies, measuring their impact on greenhouse gas emissions. We looked only at approaches that are technically feasible and likely to be commercially available no later than 2030.

Our findings indicate that by...