9.1 Introduction
9.1.1 Summary of knowledge assessed in the Third Assessment Report
The Third Assessment Report (TAR) of the IPCC identified a range of impacts associated with climate change and variability, including decreases in grain yields; changes in runoff and water availability in the Mediterranean and southern countries of Africa; increased stresses resulting from increased droughts and floods; and significant plant and animal species extinctions and associated livelihood impacts. Such factors were shown, moreover, to be aggravated by low adaptive capacity (IPCC, 2001). Many of these conclusions, as shown below, remain valid for this Fourth Assessment Report.