Influences of Mankind on Climate

There is a growing realization, both in and outside of the scientific com­ munity, that mankind does indeed have the capability to modify the climate of our planet on a global scale. The purpose of this review is to outline the various human activities that can cause such climatic changes, to indicate the state of our knowledge of the system that determines our climate, and to draw a of climatic scenario of the future. The last step involves a prediction, and it is important to make a dis­ tinction between of the natural behavior of the climate on one hand and a specification of its behavior as we inadvertently alter the characteristics of the atmosphere or land surface. We are still very far from a generally accepted technique for making useful of weather and climate for a season or a year ahead, and indeed there are the pessimists who believe that the noise of the more-or-Iess random daily fluctuations of the weather patterns will always stand in the way of long-range weather or climate forecasts. There is a second of prediction, however, that is based on the knowledge that some feature or boundary condition of the climate system will be changing in a specified way, and then estimating how the climate system will respond to that change. The success of such predictions of the second kind [Lorenz, Appendix 2.1 in Global Atmospheric Research Programme (GARP) 1975] depends on the degree to which we can specify the course of the future external influence, be it natural or anthropogenic, and the degree to which our theoretical models of the climate system