Carbon stocks of tropical land use systems as part of the global C balance: effects of forest conversion and options for clean development activities

Abstract

Around 1890, Arrhenius, a Swedish chemist, was the first to predict a quantitative increase in global temperature (of 5 to 6 degrees Celsius) due to a doubling of the atmospheric concentration of CO2 resulting from the use of fossil fuel. But to him, living in Sweden, this could only have a positive effect on human livelihoods. In a 1908 paper he remarked: 'By the influence of the increasing percentage of carbonic acid in the atmosphere, we may hope to enjoy ages with more equable and better climates, especially as regards the colder regions of the Earth, ages when the Earth will bring forth much more abundant crops than at present for the benefit of the rapidly propagating mankind” (Christianson, 1999). In the 100 years since then, have Arrhenius’ predictions come true? And have attitudes changed? Certainly, in the last two decades, global temperature has increased steadily, and this has corresponded with a sharp increase in atmospheric CO2 concentrations (Figure 1). During the last 10 years the possibility that human activities can, and do, change climates all over the earth, has moved from the realms of a scientific debate to the general recognition that this change needs to be controlled, and to an international convention that tries to do so (UNFCCC- the United Nations Framework Convention on Climate Change)