According to the Cicero Center for International Climate Research, cement manufacturing is No. 3 in carbon dioxide emissions behind fossil fuels and land-use change and the pace of production has increased by 30 times since the 1950s and by 40 times since 1990. Part of this growth is reflective of increased construction activity in China and other countries that have seen construction booms during the past few decades. U.S. Concrete says that one ton of cement production releases one ton of carbon dioxide into the atmosphere.