1. Introduction
Climate change refers to a statistically significant variation in either the mean state of the climate or in its variability, persisting for an extended period - typically decades or longer - (VijayaVenkataRaman et. al., 2012). Climate change may be due to natural internal processes or external forcing, or to persistent anthropogenic changes in the composition of the atmosphere or in land-use. Climate change has long-since ceased to be a scientific curiosity, and is no longer just one of many environmental and regulatory concerns. Ever since the Industrial Revolution began about 150 years ago, man-made activities have added significant quantities of green house gases (GHGs) to the atmosphere. …show more content…
Easterling and Apps (2005) stated that a lack of appropriate physiological models that relate climate to animal physiology rather limits the confidence that can be placed in predictions of impacts. It is clear, however, that warming will alter heat exchange between animal and environment, and feed intake (SCA, 1990), mortality, growth, reproduction, maintenance, and production are all affected, potentially. Hahn (1999) reported that giving the thermal comfort zone for temperate-region adult cattle as being in the range 5–15 °C. McDowell (1972) noted that significant changes in feed intake and numerous physiological processes do not occur in the range 5–25 °C. However, the thermal comfort zone is influenced by a range of factors, and is much higher in tropical breeds because of both better adaptation to heat and the lower food intake of most domestic cattle in smallholder systems. Clearly, hot and humid conditions can cause heat stress in livestock, which will induce behavioral and metabolic changes, including reduced feed intake and thus a decline in …show more content…
One of the most significant of these is the impact on human health. As with livestock diseases, the changes wrought by climate change on infectious disease burdens may be extremely complex. Patz et al. (2005a) list several diseases as high priority for their large global burden of disease and their high sensitivity to ecological change. For the tropics, these include malaria across most systems; schistosomiasis and lymphatic filariasis in cultivated and inland water systems in the tropics; dengue fever in tropical urban centres; leishmaniasis and Chagas disease in forest and dryland systems; meningitis in the Sahel; and cholera in coastal, freshwater and urban systems. While climate change impacts may have few direct impacts on other important diseases such as HIV/AIDS, climate variability impacts on food production and nutrition can affect susceptibility to HIV/AIDS as well as to other diseases (Williams,