Bangladesh, one of the most densely populated countries in the world, has long been witnessing an abnormal shift in its traditional six seasons due to changes in temperature, wind-flow and rainfall patterns, threatening the country’s future food security, according to local environment and weather experts.
They also said frequent natural disasters like flashfloods, cyclones, growing incidents of lightning strikes and landslides, induced by global warming are also causing huge losses to human lives and natural resources.According to a recent report of Global Climate Risk Index 2019, Bangladesh is the seventh most-affected country in the world due to “extreme weather events” over the last 20 years from 1998 -2017.
The report also said 407 people died in Bangladesh in 2017 due to extreme weather-related events while the country suffered an economic loss of about USD 2,826.68 million during the same period.
Talking to UNB, M Abdul Mannan, a senior meteorologist at the Bangladesh Meteorological Department (BMD), said Bangladesh has been experiencing abnormal behaviour of the weather pattern over the recent few years with a change in length and duration of sessions. “We can’t now predict when a season will exactly start or end due to a freak behaviour of weather.”
For example, he said, “We felt less cold during December last year and the length of winter was very short that year. But we’re witnessing that mercury dropped in December this year, but the intensity of clod is not at the expected level. The winter season will be very short this year as well as we may see rise in temperature from mid-January. Usually, winter begins early December and ends on February 28 in Bangladesh.”
Besides, Mannan said, a depression was formed over the Southwest Bay and adjoining areas this month which is very unusual. “We’re supposed to experience such disturbance during pre-monsoon (March-April) period, but we didn’t face it at that time.”
He said the rainy season was very dry this year and its duration was short with inadequate rainfall, hampering paddy, jute and other crop cultivation. “The situation was so bad that the farmers in the country’s northern region had to cultivate paddy with groundwater for lack of rainwater during the rainy season. It’s very unusual behaviour of weather.”
Mannan also said several heatwaves swept the country during rainy season-–June, July and August–this year which also an unusual behaviour of weather. “We’re facing the growing number of cyclones, floods, lightning strikes and landslides as seasons in Bangladesh are shifting a bit arbitrarily,” he added.
According to BMD statistics, the lightning frequency is gradually rising in the country during pre-monsoon period since 1981 due to change in the thunderstorm formation area along with other causes like deforestation, climate variability and global warming.
“We’re observing greater number of fatal incidents of lightning in recent years due to global warming,” said.Mannan said nearly 200 people were killed in lightning strikes this year and 270 in 2017.Bangladesh’ noted environmental expert Dr Atiq Rahman said the country’s farmers are facing immense difficulties with the cultivation of various crops due to abnormal weather events.
Citing an example, he said, farmers face problem in rotting their jute plants for lack of rainwater while they cannot plant their paddy during the traditional monsoon period for lack of adequate rainfall.Besides, Dr Atiq said, the winter is getting less biting one gradually but causing greater fogs. “Crops are being affected adversely with the increased fogs.”
He said disorders are now visible in the pattern of traditional seasons of Bangladesh due to the rise in temperature affecting the flowering periods of various other plants. “The overall uncertainty in crop production in Bangladesh is on the rise.”
Dr Atiq, executive director of the Bangladesh Centre for Advanced Studies, think warmer weather and climate change are causing more water evaporation from the land and ocean, increasing cumulonimbus cloud which is generating fatal lightning strikes in Bangladesh and its adjoining regions.
Another eminent climate expert Ainun Nishat thinks wind-flow and precipitation pattern always play a role in breeding of animals and plants. “The rise in temperature and changes in wind-flow and rainfall patterns ultimately lead to a disarray in the agricultural calendar that has long been followed by the farmers of the country. It’s also harming the food chain.”
Mentioning that rainy season comprises the cultivation and harvesting periods of the country’s major crops like paddy and jute, he said annual rainfall intensity has declined in the country over the last few years.
Dr Nishat, Professor Emeritus of BRAC University, said as the seal level is rising due to global warming as the annual rise in sea level in Bangladesh ranges between 6mm and 20mm. “It’ll have a serious impact on the country in the future as salinity will be increased.”
According to the annual report 2016 of BRAC, an international non-government organization based in Bangladesh, some 27 million people are “predicted to be at risk” of sea-level rise in Bangladesh by 2050.
It said two-thirds of the country’s land is less than five metres above sea level, and floods are increasingly destroying homes, croplands and damaging infrastructure.Approximately 10,000 hectares of land is lost every year due to riverbank erosion, the port said.
It said agricultural land is shrinking by 1 percent annually while the population is growing by 1.2 percent. This is creating a rise in demand for food, while increasingly unpredictable weather conditions pose a growing challenge to farmers trying to meet those demands, the report added.