Agriculture
Global mean temperature increase can deplete water resource systems and cause agricultural yield losses:
At present, the greatest pressure on water resources results from rising human populations, particularly in urban areas. Increase in water requirements due to increased agricultural production to meet the growing needs of a burgeoning population, and rapid economic growth to tackle widespread poverty, would substantially increase total water requirements in Bangladesh. Simultaneously, climate change is expected to decrease freshwater availability in large river basins (IPCC, 2007). Projected changes in the timeline and distribution of rainfall will impact current cropping and harvesting patterns. The lack of potential water storage facilities means that the available water cannot be used to compensate for the seasonal requirements of freshwater for cultivation. Climate change is also projectedto further decrease dry season water flows in Bangladesh, which will impact groundwater storage and soil moisture content due to high evaporative losses.
There will be significant changes in land classes that are widely used for crop production: Mirza (2003 and 2005) estimated substantial changes in land categories due to an increase in the magnitude of floods and the extent of flooded areas. Changes in inundation categories may result in reduced cropping intensity in Bangladesh. The agricultural sector of Bangladesh may suffer substantially from this loss of land productivity. The World Bank (2010) also estimated similar trends in land class changes.
Sea level rise and salinity intrusion can increase the loss of agricultural lands and food insecurity in the coastal region:
Rising sea-level will permanently inundate vast agricultural lands, making them unsuitable for crop agriculture in the coastal area of Bangladesh. Saltwater intrusion could progress further inland in the future through tidal inflows, increasing soil salinity seasonally or permanently. A World Bank (2000) study suggests that increased salinity from a 30cm sea level rise would cause a net reduction of 0.5 million metric tons of rice production, which could feed about 3 million people for a year.
There will be significant changes in land classes that are widely used for crop production: Mirza (2003 and 2005) estimated substantial changes in land categories due to an increase in the magnitude of floods and the extent of flooded areas. Changes in inundation categories may result in reduced cropping intensity in Bangladesh. The agricultural sector of Bangladesh may suffer substantially from this loss of land productivity. The World Bank (2010) also estimated similar trends in land class changes.
In the National Climate Change Vulnerability Assessment (NCVA) report, 2018: three main climate vulnerability assessments have been conducted with respect to agirculture, namely, vulnerability to land loss, vulnerability to decrease in water quality and availability, and vulnerability of crops (potential decrease in yields).
Climate Vulnerability assessment in agricultre
The analysis, indicates that the vulnerability of crop yield is low to medium. This analysis corroborates the view of sectoral experts who participated in the national workshop, and argued that rice crops are growing well, and may not be particularly vulnerable. However, seasonal flash floods currently damage boro rice almost every year. Participants at the regional workshop in Sylhet raised this as a chronic problem for farmers of the area. There is concern that the yield of rice crops, in particular boro rice has been steadily declining. Findings from the regional workshop and the FGD sessions have recorded similar voices. In some southern coastal areas, crop yield may suffer due to increased salinity. As shown in the map, crops in the areas along the Meghna are flooded every year.