The first line of The Waste Land (published in December 1922), a masterpiece of T S Eliot, is “April is the cruelest month”. That has become environmentally true after 100 years. Global warming is nothing new but it is an undeniable fact that summers are getting gradually hotter. April 2022 had the highest temperature in 122 years.
The threat of global warming is now evident everywhere. Attention is required to search for the source of this heat. In this situation, a question naturally arises. In the context of global warming and climate change, there are various policies for sustainable development but have heatwaves and other climate-related issues been given importance in policymaking? Overall, researchers did not find its reflection in practice. But it is clear from meteorological data that the amount of burning in summer is increasing every year.
Bangladesh meteorologist Mohammad Tariful Newaz Kabir said that in 1965 the maximum temperature of Dhaka reached 42 degrees Celsius. Earlier in 1960 it was 42.3 degrees Celsius. The highest temperature recorded in Rajshahi was 45.1 degrees Celsius on 18th May 1975. That is the record in Bangladesh so far. A study by the Department of Architecture of BUET showed that the average temperature in Dhaka is 4-6 degrees Celsius higher than in areas with trees and water bodies. Moreover, due to the gradually increasing use of air conditioners, the temperature outside the building rises. According to Meteorological Department, the temperature of Dhaka has increased more than 1.5 times compared to other places in the country during the last 100 years.
Environmentalists say that indiscreet development and construction work are the main causes of warming. Dhaka (and other places) is a glaring example of it. As more people are moving to Dhaka, pressure on its environment is increasing. Construction has increased in a small space to accommodate many people. The construction sector has gone almost doubled in the last twenty years. The amount of green space has alarmingly decreased. In many places cutting down century-old trees in the name of the expansion of roads is a common sight.
Construction is also going on by destroying green or filling swamp land. Due to the increase of multi-storied buildings heat refraction is increasing. Walls of lime and brick dust and windows of wooden Venetian blinds are now obsolete. Now concrete, steel, glass and aluminium are reigning and heat is continuously increasing. When the maximum daytime temperature is 40 degrees, the temperature of heated building structures is 1.5-2 times more which takes a long time to become normal. So, the burning of the sun continues also at night. Increasing construction structures is blocking the normal flow of air. Not only the upper class, but air conditioners have also entered middle-class houses. The house is temporarily cooling but the blast of outgoing hot air is heating the environment. Cities are now like insulated islands.
According to experts, an ideal city requires 20%-25% road of its total area whereas Dhaka has only 7%-8%. Professor Shamsul Haque of BUET says that this amount is very insufficient for around 2 crore people. Traffic density is very high and the movement of vehicles is slow. Traffic congestion is creating particle pollution (particulate matter PM 2.5, PM 10 and nitrogen dioxide NO2.) and coarse particles carry toxic heat. Air pollution caused by nearby industries is severely damaging the ozone layer which acts as a protector of the atmosphere. Reaching the surface harmful ultraviolet ray is heating everything.
A piece of research by the Bangladesh Institute of Planners shows that in 1999 open space in Dhaka was 14%. Now it is only 4.61%. The amount of green area has decreased by about 38% percent in 20 years. As reported in the Bengali daily ‘Bangladesh Pratidin’ (13-5-2023), Dhaka South City Corporation has cut down 563 trees in the name of beautification in Dhanmondi. Many trees in other places have been cut down by different organisations. As a result, greenery in the city is decreasing and temperature is rising. According to international standards, 25% of a city should be covered with greenery whereas Dhaka has only 8%. In the name of development, protectors are sawing even that 8%. Rainfall is associated with trees. Where there is green, there is biodiversity. Road dividers have been made smaller by cutting these trees. Except flower plants, large trees cannot be planted there. However, DSCC Mayor said that cutting trees is very sad but we only do it when there is absolutely no other way. According to him, three trees will be planted against one tree felled. Critics say that it is not a solution because a plant takes around 20-25 years to get matured. During this period, the situation will turn terribly worse.
The writer is a former Commissioner of Taxes