Long-term changes in temperature and weather patterns are referred to as climate change. Such fluctuations may be brought on by significant volcanic eruptions or variations in the sun's activity. But since the 1800s, human activity -- primarily the combustion of fossil fuels like coal, oil, and gas -- have been the primary cause of climate change.
In the last few months, Bangladesh has been facing inordinately high temperatures affecting the people's health. According to the weather forecasting report temperature in Dhaka city goes between 33 degrees to 35 degree Celsius -- which is intolerable for everyday life.
The Intergovernmental Panel on Climate Change (IPCC) has issued a warning that the increase in global temperatures must be limited to 1.5 degree Celsius or less and 1 degree Celsius, which means that the time to act is now. If we started to take action immediately we may reduce carbon dioxide levels in the atmosphere by up to 25% -- levels last seen about a century ago, according to the global tree restoration potential study. Planting trees is accessible, affordable (at least in comparison to high-tech carbon devices whose effectiveness hasn't been established yet), and simple for the general public to participate in.
Trees are our most effective tool in the war against climate change. As trees grow, they help stop climate change by removing carbon dioxide from the air, storing carbon in the trees and soil, and releasing oxygen into the atmosphere. In the city of Dhaka alone, there is close to 4,500 hectares of rooftops which are underutilized. The sole purpose of Green Savers was to instill environmental awareness among city dwellers and cover the city with green roofs.
As they expand, trees take in carbon dioxide, and the carbon they store in their wood slows the rate of global warming. As they lose moisture and reflect heat upward from their leaves, they lower wind speeds and chill the air. One of the research outcomes showed trees may cool cities down by up to 7 degree Celsius. With their ability to hold hundreds of litres of rainfall, trees also aid in reducing soil erosion and flooding.
Every community benefits from having trees. By introducing natural features and wildlife habitats into urban areas, trees improve the quality of life. The heat island effect brought on by paved surfaces and commercial buildings can be lessened in cities by simply planting more trees.
By supplying oxygen, enhancing air quality, reducing climate change, conserving water, maintaining soil, and giving shelter to wildlife, trees benefit their surroundings. Trees also absorb carbon dioxide during photosynthesis and turn it into the oxygen we breathe. One acre of forest may absorb six tons of carbon dioxide and emit four tons of oxygen, per the US. Department of Agriculture. This is enough to cover 18 people's annual needs. By eliminating dust and absorbing other pollutants including carbon monoxide, sulfur dioxide, and nitrogen dioxide, trees, shrubs, and turf also act as air filters. Rain washes harmful particles to the ground after trees catch them.
By reducing the effects of the sun, rain, and wind, trees regulate climate. The radiant energy of the sun is absorbed and filtered by leaves, keeping things cool in the summer. By acting as a windbreak, trees also keep the heat in. They not only control wind direction and speed, but also protect us from precipitation such as hail, sleet, and rain. By maintaining low levels of carbon dioxide, trees also lower air temperatures and lessen the intensity of the greenhouse effect's heating.
The best places to put trees and other vegetation as a mitigation approach is around buildings and pavements. According to research, it is usually best to plant deciduous trees or vines to the west of a structure to provide shade for windows and a portion of the roof. It's also completely visible that some places in Dhaka city next to the roads have lots of trees which look very beautiful and with comparatively lower temperature than that of other areas.
Although individual trees and shrubs have value and can help save money, a well-maintained landscape as a whole has the biggest impact on property value and has a meaningful economic benefit. When a home is shaded by a tree, cooling costs are reduced, and when a tree acts as a windbreak, heating costs are reduced. The USDA Forest Service states that strategically positioned trees around buildings can lower the need for air conditioning by 30% and save 20–50% on heating energy.
Climate change is very real, and we only need to just live our everyday lives in our capital to truly to understand that.
Mahmodul Hasan Shesheir is a Research Assistant at the BRAC James P Grant School of Public Health, BRAC University.
