Acement factory emits 900 kilograms of co2 to produce 1,000 kilograms of cement. a fully grown tree removes six kilograms of co2 per day from the air. one acre of land can support 200 mature trees. a company builds a factory that will produce 100,000 kilograms of cement. to make the factory carbon neutral, the owners need to grow trees over an area of land measuring acres.