Abstract
The emission of ozone precursors as CO, and NOx has increased over the last decades, this report looks at how this increase potentially could affect the concentration of tropospheric ozone over India. It gives a short introduction in the different sources and sinks of ozone in the troposphere, and how an increase in ozone can affect the radiative forcing. I have perturbed the anthropogenic emissions to a worst case scenario for 2050 to look at how the surface air quality will be affected, and how this increase will affect the radiative forcing, and the surface temperature. All simulations has been done by Oslo CTM3. This is a three dimensional global chemical transport model (CTM). When calculating the change in radiative forcing and surface tempera ture I have used equations from the IPCC fourth assessment report, together with the change in ozone concentration, and methane lifetime from the model. What we see is that the ozone production is highly sensitive to both meteorology, and emission of ozone precursors. Increasing the emission of CO, NOx and VOC gasses will lead to increased ozone production, high solar radiation increases the chemical production, and also reduces the deposition to the ground. Increasing the emissions to simulate a worst case scenario for 2050 gives an increase in surface ozone up to 50%, resulting in concentrations as high as 50-70 ppbv over the continents. These concentrations exceeds the World Health Organization (WHO) recommendations for air quality and can damage the vegetation and be dangerous for human health. The large increase in NOx is also so high that it will exceed the level recommended by WHO in the larger cities. We also see a increase in the surface temperature as a result of increased concentrations of both ozone and methane in the troposphere. My calculations show that as a result of increased tropospheric ozone there will be a global increase in surface temperature of 0.003 K. And the increase in methane as a result of a decrease in OH oncentration will according to my calculations lead to a increase in global surface temperature of 0.0019 K. This means that if no precautions is taken, and the increase in anthropogenic emissions keeps on increasing the surface pollution will be dangerous for both human and vegetation, and the radiative forcing will be affected.