Agriculture Reference
In-Depth Information
19.1 INTRODUCTION
Significant variation in either mean state of climate or in its variability,
persisting for an extended period (typically decades or longer) is referred
as climate change, which may be due to natural internal processes or ex-
ternal forcing or to persistent anthropogenic changes in the composition
of the atmosphere or in land use (NRAA, 2014). Climate change is being
perceived as greatest threat to mankind in twenty-first century however,
its nature, extent and magnitude are variable in different regions and loca-
tions. Indian agriculture is very diverse due to wide range in edapho-cli-
matic conditions. Over the past century, surface temperatures have risen,
and associated impacts on physical and biological systems are increas-
ingly being observed (PRC, 2007). Rise in temperature shall enhance res-
piration rate, reduce crop duration, alter physiology of flowering, fruiting
and hasten ripening and maturity which may adversely affect the crop pro-
ductivity and adaptability. Earlier studies conducted in India also gener-
ally confirm the trend of agricultural decline with climate change (Sinha,
1993). Climatic extremes like droughts, floods, tropical cyclones, heavy
precipitation events, hot extremes and heat waves are mainly originated
and triggered by climate change causes negative impact on agricultural
production. It has been projected by the recent report of the IPCC and a
few other global studies that unless we adapt, there is a probability of 10-
40% loss in crop production in India by 2080-2100 due to global warming
despite beneficial aspects of increased CO
2
(Parry et al., 2004). According
to the Intergovernmental Panel on Climate Change's (IPCC) Fourth As-
sessment Report of 2007 (AR4), climate change can reduce agricultural
yields as much as 50% under rainfed farming. In India rainfed agro-ecol-
ogies contribute 60% of the net sown area (Vision, 2050) hence climate
change is expected to cause serious difficulties for Indian agriculture.
Arid and semiarid regions of India are more prone to climate change
and experiencing erratic and poor rainfall and temperature induced cli-
matic extremes. Increase in atmospheric temperature and change in pre-
cipitation pattern due to climate change has significantly raised the sea
level and steadily shifted/moved the climatic zones of country. The cli-
mate change also affects the atmospheric temperature and relative humid-
ity which are the major factors affecting infestation of pests and diseases.
Climate change projections made up to 2100 for India indicate an overall
increase in temperature by 2-4°C with no substantial change in precipi-
