Causes And Effect Of Temperature Essay

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3. Impacts of elevated temperature Increased greenhouse gases causes increasing global mean temperature. Global mean temperature will increase by 1oC above present value by 2025 and by 3oC by 2100. In temperate latitude, temperature rises will causes increased photosynthesis and respiration of plants. Rising temperature shows respiration increasing more than photosynthesis. It causes an autocatalytic component to global warming. High temperatures limit growth, development and ultimately adversely affecting crop yield. Detrimental effects of high temperatures have been observed during both the vegetative and reproductive stages of various plant species. However, reproductive stages are most sensitive to high temperature stress compared to vegetative stages. High temperature induced reduction in the crop yield is attributed to the negative effects of high temperature stress on cell structures and physiological and metabolic processes. High temperatures disrupt the integrity of cellular membranes and cause changes in enzyme activity that lead to alterations in the rates of biochemical reactions and ultimately an imbalance in metabolic pathways. The molecular basis of high temperature damage involves changes in protein conformation (Berry and Bjorkman 1980; Levitt 1980; Larkindale et al., 2005). Plants may be exposed to severe high temperature stress during germination, which can cause loss of vigor, ultimately leading to reduced emergence and seedling establishment. During
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