40% of the U.S. carbon dioxide emissions come from power plants that burn fossil fuels to make electricity.
Coal accounts for 93 percent of the emissions from the electric utility.
Coal emits much more carbon per unit of energy when burned than both oil and natural gas causing there to be more pollution and greenhouse gases.
The waste that factories make can harm surrounding forests and trees causing the carbon dioxide to hang around in the air and go into the atmosphere.
Methane can also be created in the making of different products.
Beside the natural excretion of water vapor, industries add extra huge amounts when they are burning things or making products.
Even in regular Buildings there is some carbon dioxide increased which makes a difference.
Other Human Causes are automobiles and agriculture pollution.