It can sound surprising, but after water, concrete is the most used substance in the world. Concrete is the foundation of modern development in the world. The same goes for Bangladesh as well. Over the decades, concrete has been in the driving seat of our country’s development, putting rooftops over the heads of millions of people, building a defense against natural disasters, and providing health care, education, transportation, and energy industry infrastructure. We are using concrete to conquer the sky and tame nature. Concrete blocks protect us from the threats of being in the open. Concrete is keeping the rain away from our heads, mud away from our feet, and cold away from our bones. But concrete is also creating the most dangerous gas and polluting the atmosphere. It is sucking up the fresh water and causing infertility of lands. It is constipating rivers and choking natural habitats. While concrete is driving us into modern development, it is also driving our environment into disaster.
The popularity of concrete is rapidly growing in Bangladesh. Due to its durability, the real estate industry is using concrete blocks in most of their project nowadays. However, every coin has its flipside. Though concrete provides a large set of benefits, it also brings a huge disaster to the environment. The environmental impacts of concrete blocks generate from their components. The main component of concrete blocks is cement. The production of cement has a huge environmental impact. If the concrete industry was a country, it would be the world’s third-highest carbon emitter.
Greenhouse Gas Effect
The cement industry in Bangladesh is considered to be one of the main producers of carbon dioxide. According to UK-based think tank Chatham House, cement is the source of more than eight percent of the world’s carbon dioxide emissions. Carbon dioxide is one of the potent greenhouse gases. Greenhouses gases absorb the infrared radiations and create a greenhouse effect. Similar to the actual greenhouses that trap heat from the sun within the glasshouse to grow the plant, greenhouses gases trap heat radiated back from the earth and make the earth’s atmosphere warmer.
As the demand for concrete increases, the need for cement increases in tandem. The more cement production, the more carbon dioxide gets released into the environment. Carbon dioxide is one of the primary contributors to global warming- a phenomenon of a gradual increase in the earth’s average temperature. As the average temperature of the earth increases, the icebergs in the poles begin to melt. As a result, the earth’s sea level is rising each year. A lot of coastal areas are now in danger of being completely underwater in the coming years. Moreover, greenhouses gases contribute to the formation of natural disasters such as tornadoes and tsunamis.
Dhaka is getting hotter each summer. Life in the capital city of Bangladesh becomes unbearable at times due to the extremely hot weather in summer. The environment experts believe concrete is one of the primary contributors to the urban heat island effect. People residing in concrete buildings are using air conditioners to deal with the extreme summer heat. But air conditioners are emitting greenhouse gases into the atmosphere and contributing to global warming. Hence, we are trapped in a vicious cycle of increasing greenhouse gases that are causing extreme hot weather in urban areas.
Air Pollution and Smog
According to the news of Prothom Alo, the air of Dhaka is one of the most polluted in the world. The air in the capital city is filled with dust. When the dust particles get mixed with the gas emitted from cars and factories, smog is formed. Smog is extremely harmful to human health. It can severely damage the lung and other inner organs. Researchers have found that concrete dust largely contributes to smog creation. The air quality in Bangladesh has been sharply declining over the last decade. As many mega infrastructure projects are ongoing in Dhaka, concrete is being heavily used. These megaprojects are releasing an extreme amount of concrete dust into the air and adding to the air pollution.
The concrete industry is heavily dependent upon freshwater. To prepare concrete blocks, you need gallons of water. From preparing the concrete mixture to the strengthening process of concrete blocks, freshwater is required in each step. The concrete industry is often compared with a thirsty behemoth that is sucking up more than ten percent of the world’s total industrial freshwater use. Bangladesh is at risk of facing a freshwater crisis in the upcoming decades. The concrete industry greatly contributes to that risk.
The concrete block requires water to strengthen. Upon pouring, concrete mixtures absorb the water from the land. If one repeatedly continues the process of concrete pouring into the same surface, the surface will soon run out of water. In addition, the land surrounding the concrete pouring area is often at risk of becoming infertile.
Surface runoff is a phenomenon when liquid material runs off impervious surfaces or water-resistant surfaces. Impervious concrete blocks can induce surface rain and can cause soil erosion and flooding. In urban areas, surface runoff can become an issue during rain; impervious concrete blocks cannot absorb the water. Hence, if the ground area is made of concrete, water can jam and create waterlogging. Especially in Dhaka, we face extreme waterlogging during the monsoon season because the concrete streets cannot absorb the rainwater fast enough.
While we are ripping the benefits from concrete, concrete is taking away our natural resources. However, we can find a balance in preparing concrete in such a manner that the environmental impacts can be put to a minimum. Green concrete brings that balance to the equation. Green concrete is an eco-friendly concrete that is prepared from waste or residual materials from various industries. Moreover, it requires far less energy than traditional concrete. Most importantly, green concrete produces carbon dioxide at a far lower rate than traditional concrete. Green concrete is also cheap and durable. The primary goal of green concrete is to minimize the burden on natural resources and increase dependency on the material that can be recycled. Green concrete is sustainable and has the potential to become an eco-friendly alternative to traditional concrete.
The Concrete blocks in Bangladesh taking our civilization upward- literally building skyscrapers and creating living spaces in the thin air. Concrete blocks are making mega infrastructure projects like metro rail possible. As the concrete block is greatly contributing to Bangladesh’s development towards a modern nation and taking us upwards, it is also pushing our carbon footprints outwards- sprawling across the fertile lands, choking the natural habitats, squeezing out the freshwater reservoir. For decades we have agreed to accept the environmental downside of concrete blocks in exchange for undoubted benefits from their durability. However, considering the current environmental situation of our country now is really the time to find a balance in using concrete blocks while minimizing the environmental impacts.
How can I avoid surface runoff in my concrete parking space?
Ans: Pervious concrete blocks can be produced using the right mixture of aggregates. Pervious concrete blocks have a higher capability to soak up the water.
How to reduce concrete dust in my project sites?
Ans: Using water will greatly reduce the concrete dust. However, it will be wise not to use freshwater just to wet the concrete blocks.
How can I stop soil degradation in the lands adjacent to my concrete pouring site?
Ans: There is no way to stop it. Hence, one should avoid pouring concrete into nearby fertile lands that are being used for growing crops.
Are there environmentally friendly concrete blocks available in Bangladesh?
Ans: Yes. There are green concrete blocks available in the Bangladeshi market.
What is an eco-friendly option to mitigate urban heat?
Ans: Trees are the best choice to mitigate urban heat. If all buildings in Dhaka use their open area to plant trees, the summer heat will drastically go down.