Climate Change Vulnerability of Crop Agriculture

Abstract

A simulation study was conducted to assess the vulnerability of foodgrain production due to climate change in Bangladesh. Two general circulation models were used for development of climate scenarios. The experiments considered impact on three high yielding rice varieties and one high yielding wheat variety. Sensitivity to changes in temperature, moisture regime and carbon-di-oxide fertilisation was analysed against the baseline climate condition. The GFDL model predicted about 17 per cent decline in overall rice production and as high as 61 per cent decline in wheat production compared to the baseline situation. The highest impact would be on wheat followed by Aus variety. CCCM model predicted a significant, but much reduced shortfall in foodgrain production. It was found that increase in 4°C temperature would have severe impact on foodgrain production, especially for wheat production. On the other hand, carbondi-oxide fertilisation would facilitate foodgrain production. A rise in temperature cause significant decrease in production, some 28 and 68 per cent for rice and wheat, respectively. On the other hand, doubling of atmospheric concentration of CO2 in combination with a similar rise in temperature would result into an overall 20 per cent rise in rice production and 31 per cent decline in wheat production. It was found that Boro rice would enjoy good harvest under severe climate change scenario. The apparent increase in yield of Boro and other crops might be constrained by moisture stress. A 60 per cent moisture stress on top of other effects might cause as high as 32 per cent decline in Boro yield, instead of having an overall 20 per cent net increase. It is feared that moisture stress would be more intense during the dry season, which might force the Bangladeshi farmers to reduce the area for Boro cultivation. Shortfall in foodgrain production would severely threaten food security of the poverty ridden country.