Climate change is manifested in a range of short-term weather events and long-term climatic trends that are deeply affecting agricultural systems, especially the rain-fed and subsistence ones. The most common changes being witnessed are unreliable rainfall periods (delayed commencement or early cessation of rains), erratic rains, leading to extended dry spells punctuated by intermittent rainfall events, heavier-than-usual rainfall events and above-average air and soil temperatures.
Crops are dependent on temperature, light, moisture and CO2 to produce grains and other crop products to satisfy the basic human needs. Climate change is very likely to affect food security at the global, regional, and local level. Climate change can disrupt food availability, reduce access to food, and affect food quality. Increases in temperature, changes in precipitation patterns, changes in extreme weather events, and reductions in water availability may all result in reduced agricultural productivity.
Higher CO2 levels can affect crop yields. Some laboratory experiments suggest that elevated CO2 levels can increase plant growth. Though rising CO2 can stimulate plant growth, it also reduces the nutritional value of most food crops. More temperature both high and low and precipitation can prevent crops from growing. Extreme events, especially floods and droughts, can harm crops and reduce yields. These are a source of rising concentration of greenhouse gases which in turn are the major reasons of global warming and other changes in climate The climate change is characterized by rising temperature, erratic and lower rainfall declined frequency but with greater intensity, changing seasons, and occurrence of extreme events floods and droughts.
Resource poor farmers are greatly affected by these changes that result in lower or failed agricultural production, higher incidence of pests and diseases, and an overall reduction in the efficiency and productivity of farming systems. There is an urgent need to adapt traditional agricultural systems to these changes in order to make them more resilient to climatic shocks and stresses. Broader actions are also needed to mitigate climate change itself in other words to actually reduce the magnitude or rate of climate change.
Climate Smart Agriculture may be a viable mitigation tool that includes both new and old agricultural practices that are considered effective in helping farmers adapt to climate change and among some groups to mitigate climate change. Apart from this varieties which are tolerant to high temperature and drought should be developed so that losses could be avoided. The temperature component may shorten the growth periods; therefore the cultivating time should be adjusted accordingly.