Attempts to Separate the Effects of Aerosol, Greenhouse Gases and Urbanization in the Temperature and Precipitation Trends in China

Climate changes result from all forces, natural and anthropogenic. Among various anthropogenic factors, greenhouse gases, aerosol and urbanization are arguably the most significant ones whose effects are often hard to differentiate, as they often come into play simultaneously due to human activities. It is, however, extremely, important to separate their effects for the sake of both science (e.g. accounting for them in GCMs) and for making sound policy in light of their diverse implications. Few places in the world are more affected by all three factors than China where decades of fast development have drastically altered atmospheric and terrestrial environment with huge greenhouse emissions. Such changes have left deep footprints in the climate system. While the anthropogenic impact is substantial, it is a nontrivial task to detangle them. In this talk, I will present a pilot study showing how changes in temperature and precipitation are linked with these factors with a particular focus on temperature and precipitation. From their long-term observations, we are able to see the contributions of increasing air pollution to mean, maximum and minimum temperatures, and rainfall of varying intensity from drizzle to thunderstorms.