Carbon dioxide (CO2) is one of five primary greenhouse gases (GHG) recognized by the Intergovernmental Panel on Climate Change (IPCC). Many of these gases are produced by both natural and human activities, but particular attention has been given to CO2 emissions since they account for the vast majority of manmade GHG emissions (83% in the U.S.). According to the IPCC, almost all CO2 emissions come from the consumption of petroleum products, with diesel fuel accounting for 22%.
The use of SCR in heavy-duty trucks results in measurable CO2 reduction. According to original equipment manufacturers (OEM) Detroit Diesel Corporation and Daimler Trucks North America, CO2 emissions could be reduced by more than 70 tons per truck over an average lifespan of 10 operating years or 1 million miles per truck. Based on using SCR in an average fleet of 50,000 trucks per year, this would result in eliminating more than 3.5 million tons of CO2 per year over the average lifetime of the trucks put into service beginning in 2010.
SCR versus non-SCR equipped engines: Fuel Benefits and Emissions