13 Feb Global Warming and Agriculture
ग्लोबल वार्मिंग और कृषि पर प्रभाव The climate of earth is a dynamic one promoting the evolution of various living forms and changing the structure and chemical composition of the atmosphere. Over the past few decades, acceleration in the human-induced changes in the climate of the earth has become the focus of scientific and social scrutiny. The gaseous composition of the atmosphere has undergone a significant change mainly through increased industrial emissions, fossil fuel combustion, widespread deforestation and burning of biomass as well as changes in land use and land management practices. These anthropogenic activities have resulted in an increased emission of radiatively active gases, e.g., carbon dioxide (CO2), methane (CH3) and nitrous oxide (N2O),popularly known as the 'greenhouse gases'. The atmospheric concentrations of carbon dioxide, methane and nitrous oxide were 280±6 ppm, 700±60 ppb and 270±10 ppb between the period 1000 and 1750 AD (IPCC, 2001. Climate change: Impacts, adaptation and vulnerability. Inter-Governmental Panel on Climate Change, Report of the Working Group II. Cambridge, UK.) Today, these values have become 369 ppm, 1750 ppb and 316 ppb, respectively. These greenhouse gases trap the outgoing infrared radiation from the earth's surface. The process, generally referred to as the greenhouse effect, adds to the net energy of the lower atmosphere and, therefore,...