Declining sunshine takes toll on food production
The sunshine has reduced between 3.3 and 5.2 percent per decade putting long-term effects on food production particularly on rice and wheat in the country.
A team of Bangladesh University of Engineering and Technology (Buet) made the observation after analysing the sunshine data of over the last 46 years.
The highest decrease in sunshine was recorded in the winter season and the lowest in the monsoon, said principal analyst of the team Prof M Shahjahan Mondol of the Institute of Water and Food Management (IWFM) while talking to the news agency.
Prof Mondol said the team came to this conclusion after analysing data available from the sources of Bangladesh Meteorological Department (BMD), Climate Change Cell of the Department of Environment (DoE), Centre for Environment and Information Service (CEGIS) and IWFM during the period from 1961 to 2006.
“Total sunshine has been decreased 16 to 24 percent over the last 46 years. Due to the reduction in day length by 25 percent, the yield of paddy might reduce by 15 to 20 percent. The optimum day length for paddy is about 8-10 hours,” he said.
Prof Mondol said the effects of decrease in sunshine on food production remained out of sight due to use of high yielding varieties, fertiliser and other modern technologies.
He said the overall annual decrease of sunshine in Bangladesh was about 4.3 percent per decade and the highest decrease was in Dhaka and the lowest in Chandpur.
The maximum decrease of sunshine was found during the coldest period, he said, adding that the urban areas showed more dimming compared to nearby agricultural areas.
Prof Mondol said the sunshine deceased 8.87, 9.19 and 8.99 percent respectively in Dhaka, Bogra and Jessore in the winters during 1961-1975 period.
“The decline was 5.89, 6.19 and 5.84 percent respectively in those districts in winters during 1991-2006. The highest decrease of sunshine was 15 percent from March to May,” he added.
The main reasons for the decrease in the sunshine was air pollution triggered by dust, black carbon, organic carbon, sulfur oxide and other salty particles in the sky, said Prof Mondol.
Besides, there are many regional and global reasons that contributed to air pollution and cloudy weather, he said, adding that evaporation and transpiration, which are essential for plants, were also reduced due to decline in sunshine.
Comments