Project 4: The Indirect Global Warming Potential of NOx Emissions
The Indirect Global Warming Potential of NOx Emissions
The goal of this project is to investigate the overall climate impact of NOx emissions in terms of CO2-equivalence factors and to incorporate these variables into the Lifecycle Emission Model (LEM). The effect of NOx emissions on direct climate species is modeled based on results derived from primary chemical/climate literature. The net climate forcing is the sum of numerous atmospheric and surface effects. Positive climate forcing effects include increased tropospheric ozone levels (O3) due to reaction with VOCs (volatile organic compounds), and increased N2O levels from soil nitrogen fixing. Negative climate forcing effects are decreased CO2, decreased methane levels and increased ambient lifetimes, and increased particulate nitrate levels. Finally the LEM will be used to calculate the net climate forcing resulting from NOx emission pulses in various regions, based on regional NOx emission inventories. The overall expected effect is a slightly negative climate forcing and sensitivity to emissions is uncertain.