STUDENT VERSION A SIMPLE MODEL FOR CLIMATE BIFURCATION

The Earth’s climate and its variations has always been of great interest to humans as it has major impact on human activities. In this paper we present prototype models for the mean temperature of the Earth which will enable us to explore possible bifurcations in the Earth’s climate which might due in part to anthropogenic emissions and natural forcing processes. These model are based in part on the approach presented in [13, 4]. More elaborate and sophisticated models are available in the literature [8, 19, 4]. Much was written lately about the gradual change in the mean temp of the earth due to human intervention which is expected to range by 1-2 degrees by the end of this century. However the real danger of these changes is that they may lead to a rapid major change in the Earth climate (viz. climate bifurcation [3]) in the same way that a rubber band snaps suddenly when it is over stretched or a sudden snow avalanche occurs on the slopes of a mountain. The Earth climate system is composed of the following components: land, biosphere, atmosphere, ocean and the cryosphere (ice and frozen water), These components display a broad range of variability on temporal and spatial scales such as the Dansgaard-Oeschger cycles which occur quasi-periodically on a millennial time scale or the El Niño-Southern Oscillation in the equatorial Pacific. Thus a refined model of such a complex system requires vast amounts of data and elaborate sophistication. In the following we stick to the basics.