N2O emissions from global transportation

Direct emissions of N2O from global transportation (land, air, water) are estimated to be 0.142 ± 0.065 Tg N2O–N yr−1 in 2010 with the majority (≈55%) of emissions resulting as an unwanted by-product from catalytic emission control systems of light-duty vehicles. Emissions from global transportation accounted for 3 ± 1% of current estimates of the total anthropogenic emissions. With anticipated improvements in the emission control systems of light-duty vehicles, the emissions of N2O from global transportation are expected to decline to 0.108 ± 0.065 Tg N2O–N yr−1 by 2030 despite a substantial increase in global transportation activity.