Bangladesh sees sea change in climate

Iftekhar Mahmud | Update:

Autumn is the time of white clouds floating in the blue sky, matched by the long white-tufted grass of the kaashbon, and sparkling dew drops here and there.

But things have changed. Over the last few years, autumn and the rainy season have had very little difference. The autumns have been seeing the scorching heat of summer and the pouring rain of the monsoons.

The rains this time round have exceeded that of the heavy monsoons, said the meteorological office. There was a total of 155 mm of rain in the capital on Friday and Saturday, which would be about 16 cm, or 6.2 inches, in a standard vessel. Such volume of rain at this time of the year has been rare, according to weather experts.

The weather was different before these three days of torrential rain. The temperature in the capital city Dhaka and other places around the country had hovered between 34 and 37 degrees Celsius, a state which is normal only at the height of summer. But this year most of September witnessed such scorching heat.

The change in rainfall and temperature has been gradually taking place over the past 30 years.

This is seen by local and foreign researchers as the impact of climate change.

This has resulted in decreased food production in the country, increased incidence of natural disasters, disease outbreaks and large numbers of people being displaced.

Bangladesh University of Engineering and Technology (BUET)’s water and flood management institute has carried out a study in climate change in Bangladesh.

The institute’s researchers said that climate change is the cause of these rains at this time of the year. And like all over the world, there has been a rapid increase in temperature in Bangladesh.

If things go on in this manner, Bangladesh’s average temperature will go up by one and a half to two degrees within this century. If the temperature goes up by even one and a half degrees, production of the Boro and Aman rice crop will probably fall by 10 per cent. That means food production will decrease by around 4 million tonnes.

The Department of Meteorology and Bangladesh Centre for Advanced Studies (BCAS), in two separate studies, have projected the changing pattern of rainfall in the country. According to the studies, rainfall has been steadily increasing in the country’s southern region, that is, in Chittagong region, over the past 30 years. This has increased the incidence of landslides in that region.

On the other hand, rain is decreasing in the country's southwest region. This is increasing the salinity of the region which has naturally higher salinity as it is. As a result, crop production is decreasing in both regions.

The UN Food and Agriculture Organisation (FAO) recently issued a special warning to eight countries regarding food security. The organisation blames climate change for the haor (marshland) embankment breaking and crops being flooded as well as the serious floods in the mid-region of Bangladesh.

America’s agricultural agency USDA published a report in June this year concerning the state of Bangladesh’s crops. That report also pointed to climate change as the reason behind fall in crop production.

Professor of BUET’s water and flood management institute, and head of the climate research group, professor Saiful Islam said, “We had so long been talking about the possible effects of climate change. There are normally floods in the haors in April and May. This year we saw serious floods there in March. And during the floods in the north of the country this August-September, the water level reached the highest in 100 years. All this is the impact of climate change.”

Bangladesh in danger

According to the fourth assessment report of the UN Intergovernmental Panel on Climate Change (IPCC), one-third of Bangladesh will be submerged under water within this century. About 60,000 sq km of 19 districts are at risk and this may displace around 20 million people.

The BUET report has presented new data on how many coastal inhabitants will be displaced if the sea level rises, though it apprehends a lesser area being submerged. The research, headed by Saiful Islam, states that if the water level of the Bay of Bengal increases by one metre in this century, then 3930 sq km will go under water. And around 6 million people will be displaced from around 4 per cent landmass.

Saiful Islam told Prothom Alo, “The IPCC prediction was based on a global consideration, on perception. We specifically calculated the rise in water level over the past 30 years of the Bay of Bengal and the rivers connected to it. Our research was based on this trend, if it continues in this manner."

This year’s report of the international agency German Watch states that Bangladesh was hit 185 times by severe adverse weather, taking third position in the world in this regard.

Bangladesh stands in fourth position among countries facing highest financial loss due to adverse weather conditions from 1996 to 2015. And the country takes third position in the number of human deaths due to adverse weather.

Rain increases down south

According to the meteorological department, there was 70 per cent more rain than usual this month in the Chittagong division. Over the past three days alone, rainfall in Sandwip exceeded 400mm.

The meteorological , with support of Norway’s department of meteorology, last year published a detailed research report on Bangladesh’s climate. This study on the changing weather patterns from 1981 to 2010, states that rainfall in Teknaf increased by 36 per cent, in Cox’s Bazar by 22 per cent, and in Patuakhali and Barguna by 15 and 10 per cent respectively. Cox’s Bazar’s temperature increased by .50 degrees Celsius. On the other hand, rainfall decreased in Bhola, Khulna-Bagerhat and Satkhira by 20 per cent, in Feni by 25 per cent and in Madaripur by 28 per cent.

BCAS researcher Abu Sayeed carried out a study in 2016 on the impact of increased rainfall and temperatures in Bangladesh due to climate change. Presenting the change in rainfall and temperatures of over the past 30 years in the country, he pointed out that rainfall had decreased in the areas. As a result, during the rainy season where 10 per cent of the coastal area has salinity, this increases up to 40 per cent in winter.

One of the main researchers of the meteorological department’s ‘Bangladesh Climate’ study, Bazlur Rashid, told Prothom Alo, “Though rainfall has increased in Chittagong division, we noticed it has fallen in Rajshahi and Satkhira. Also, heavier rains fall in a shorter span of time. The weather is otherwise normal in other times of the year.”

New danger in lightning

This year many people died in such a phenomenon of nature that so long hadn’t been considered as a disaster. A total of 170 persons were killed by lightning this year. Over the past seven years, 1760 persons were hit and killed by lightning.

The internationally renowned journal Nature, in a report last year, said that the incidence of lightening had increased around the world due to climate change. It said that in places where temperature went up by one degree Celsius, the incidence of lightening increased by 12 per cent. Over the past 30 years, the global temperature has gone up by one degree, and so the incidence of lightening has increased too.

However, according to Bangladesh Disaster Forum’s member secretary Gowher Nayeem Wara, previously there had been many more trees in the country and the lightning would strike the trees. And the buildings would also have lightening rods. That has decreased too and so lightning directly hit people instead.

Biggest flood in 100 years

Upstream Brahmaputra saw record rainfall in 100 years. Around 8 million people in the country were affected when this water flowed down through the north and mid regions of Bangladesh into the Bay of Bengal.

Gowher Nayeem Wara, also a teacher at Dhaka University’s department of disaster management, told Prothom Alo, “The vagaries of weather are nothing new, but the increases in these are signs of climate change.”

Frequent cyclones

Climate experts say that increased temperatures of the ocean surface due to climate change is creating frequent cyclones in the Bay of Bengal. And this has affected Bangladesh the most. From 1971 to 2006, cyclones would hit Bangladesh every 4-5 years. Since 2007, strong cyclones have hit Bangladesh every other year.

Climate change leads to landslides

There have been regular landslides in the country over the past decade. Previously these would be concentrated in Chittagong and Cox’s Bazar. This year Chittagong Hills Tracts witnessed the worst landslides in living memory. So far 156 people in the hill tracts died in the landslides.

It is said that unplanned settlements and excavation of hills have led to landslides. Climate researcher Abu Sayeed told Prothom Alo that temperatures are rising in the dry season in Chittagong Hill Tracts. "This is cracking the earth there. Again, rain is increasing there during the monsoons, leading to landslides. And unplanned development is accelerating the incidence of landslides," he added.

Bangladesh’s Centre for Environment and Geographical Information Services (CEGIS)’s Deputy executive director Malik Fida Abdullah Khan told Prothom Alo, “So long we had taken up development plans based on what has happened in the past 30 years. But for the first time the matter of climate change was taken into consideration when drawing up the design for the Padma Bridge. We must keep climate change in mind when dealing with water-logging in the cities and constructing rural bridges, roads and other infrastructure.”

* This piece, originally published in Prothom Alo Bangla edition, has been rewritten in English by Ayesha Kabir, Consultant (Content) Prothom Alo English Online.

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