1. INTRODUCTION
1.1 Background of the Study
Climate change is a change of climate which attributed directly or indirectly to human activity that alters the composition of the global atmosphere (UNFCC, 2001). Climate change is a phenomenon due to emissions of greenhouse gases from fuel combustion, deforestation, urbanization and industrialization resulting variations climate elements such as solar energy, temperature and precipitation (Upreti, 1999).
Temperature rises beyond 2°C due to climate change and variability is likely to result in reduced crop yields in particular in most tropical, sub-tropical, and mid-latitude regions and some ecosystems will be irreversibly damaged or lost. It will contribute to result in much more drought and flooding in low-lying areas with decline in food production, an increase in disease, and the extinction of plants, animals, and entire ecosystems (IPCC, 2007).
Climate change and variability affects agriculture in several ways, one of which is its direct impact on crop productivity (Ziervogel et al. 2006). Global food security, which is threatened by climate change and variability, is one of the most important challenges in the 21st century to supply sufficient food for the increasing population while sustaining the already stressed environment (Lal R, et al, 2005). Climate change has already caused significant impacts especially on water resources, food security, hydropower, human health (Magadza, 2000). Studies on climate impacts and