The emission of fine carbonaceous particles in China is a serious threat to human health, ecological systems, and regional and global climate regimes. China is thought to release about 20 percent of the global black carbon through the combustion of coal and biofuels without adequate particle controls. The household and industrial sectors are mainly responsible, but the country's growing transportation sector is a concern for the future. The economic cost of damage from black carbon likely exceeds the cost of controlling emissions by several fold, but as yet such costs have not been quantified.