As a result of the Kyoto Protocol (KP) and its so-called “flexibility mechanisms,” climate change and mechanisms to mitigate its potential effects have attracted considerable economic and policy attention. A major reason for this attention is that the KP has a complex set of instruments that enable countries to achieve emissions reduction targets in a wide variety of ways, some of which are unlikely to lead to real, long-term reductions in greenhouse gas emissions. One purpose of this chapter, therefore, is to provide an overview of economic reasoning applied to climate change and to illustrate how terrestrial carbon uptake credits (offset credits) operate within the KP framework. Attention is focused on the feasibility of terrestrial carbon sinks to slow the rate of CO2 buildup in the atmosphere.1