A growing coalition of cities, NGOs, and private companies are advancing building efficiency efforts that save money and greenhouse gas emissions. Photo by Omar Barcena/Flickr.

Urbanization is reshaping the economy, energy systems, and climate of our planet. By 2050, the world’s cities are expected to add 2.

Improving building efficiency presents a major opportunity to curb greenhouse gas emissions while saving money and improving quality of life. Photo by deano7000/Flickr.

If you want to find major emitters of greenhouse gases, look no further than your city’s skyline.