Gas concentrations. Another large source of uncertainty is the expected rates of increase in the concentration of greenhouse gases in the atmosphere. These will depend on the scenarios adopted for future energy demands and supplies and other human activities. Biomass. We need to assess how localized changes from deforestation, biomass burning and emission of particles, which have a profound influence on the regional climate, interact with the global-scale warming effect of the gaseous pollutants. Of particular interest in the case of Africa is the grasslands. Oceans. The oceans play a dominant role in governing the timing and the rate of the warming because of the enormous heat capacity of oceans compared to the land. We are at the very early stages of understanding the interactions between the greenhouse warming and the dynamics of the oceans. Significant improvement in understanding this problem is needed to improve the predictions of regional climate changes. 1.1