Raising energy efficiency is the easiest way for the country to reduce its greenhouse gas emissions and improve its air quality

The whole world is looking for ways to reduce greenhouse gas emissions and conserve energy. The most powerful strategy is to find solutions that handle both problems at once. For example, if new buildings are built with modern, energy-efficient technologies, they will drastically cut energy waste, and thus carbon dioxide, the principal greenhouse gas. At the same time, they will cut their demand for electricity, cooling, and heat, which will minimize the use of power plants and heating boilers.

I mention buildings because world-class building codes, properly enforced over time, can cut their energy consumption by up to 80 percent. We know this because California has now achieved it in new buildings compared to those constructed before the present code was introduced. New York City's mayor has calculated that three-fourths of his city's energy is consumed in buildings, so he is launching a new initiative to make them more efficient. China, too, can ensure its new buildings are efficient and built to last.