Chapter 2Literature Review2.1 IntroductionClimate change is currently generally considered a major global problem that is particularly acute in developing countries. This study focuses on the impacts of climate change and variability on smallholder farmers, their vulnerability and adaptation strategies at a micro-scale in a developing country. To get a complete picture of these issues, this chapter reviews the literature on climate change and vulnerability. . It begins by defining climate change and analyzing global climate change in general and its impacts on the livelihoods of local smallholder farmers in a developing country such as Zimbabwe. Finally, the chapter also assesses adaptation measures that smallholders can use to increase their adaptive capacity and resilience to climate change and variability.2.2 Definition of climate-related phenomena2.2.1 Climate changeClimate change refers to changes in the average state of the climate or in its variability, persisting for an extended period of several decades or more (Ziervogel and Zermoglio, 2009). This is the change in average atmospheric behavior and the change in patterns of variation around this behavior (Rumbach and Kudva, 2011). The Intergovernmental Panel on Climate Change (IPCC) has stated that climate change is unequivocal, as evidenced by observed changes in several global and regional climate indicators (IPCC, 2007). At the national level, climate change refers to observable changes and permutations (undefined geographic variations) in temperature, precipitation and extreme climatic events and their unique or collective impacts on various agricultural productions (Lasco, et al., 2009 ). Climate change is largely attributed to anthropogenic factors that have caused a certain amount of paper......and feed grains (Nyong, 2008). Higher temperatures can harm the physiological development of crops, for example by causing increased respiration, shorter periods of seed formation, and reduced biomass production, leading to accelerated maturation and reduced crop yields (Adejuwon , 2004). Global warming and drought have altered the incidence and distribution of pests and pathogens, presenting challenges for crop management and livestock production. Humidity and temperature are important climatic elements that determine the occurrence and location of pests and diseases (Adejuwon, 2004). Indeed, pest and disease vectors thrive under optimal conditions of high temperature and abundant water supply. In this way, climate change and global warming have expanded the range of certain pests and diseases, thus worsening the plight of farmers..