The interface between construction activity and climate change cannot be disregarded while discussing the role and importance of both these areas in sustainability of economic development.
The construction industry and environment or climate change have two-way mutual repercussions. On the one side construction is an industry that has a lot to contribute to the climate change dynamics, negatively or positively depending on the construction techniques, while on the other side climate change impacts the construction industry itself in more than one way.
The first and foremost impact of construction is on existing natural locale and topography that is compromised in order to erect concrete and steel structures. Land erosion, desertification and dereliction are a few inevitable fallouts of large-scale construction pursuit.
The term concrete jungles is already in vogue due to incessant, unbridled and mostly unplanned construction sprees in Pakistan for decades, thanks to the real estate craze championed by tycoons and mafias running this business that involves huge profiteering. Hundreds of thousands of acres of fertile land has been sacrificed for housing extravaganza, generally to the luxurious satiation of the already rich instead of providing relief and shelter to the poor and needy.
Depletion of natural climate leads to the destruction of habitats for wildlife, flora and fauna, thus creating imbalance in the ecological order. This further disturbs the climate equilibrium, giving way to a host of harms including global warming, excessive rains and flooding, extended droughts to mention a few.
It may not be out of place to point out that experts and researchers have linked outbreaks of many endemics and pandemics to climate change – Covid-19 included. The entire lifecycle of building and construction actually affects environment in one way or the other. The lifecycle comprises production of raw material, processing and storage, transportation, manufacturing and output.
Provision of basic raw material, cement, bricks, gravel, iron, steel, other metals and wood necessarily take the toll on natural resources. Production and processing of these materials require huge amounts of energy for which fuels like coal, gas and oil are used, which emit greenhouse and acidifying gases into the atmosphere. The construction sector is highly energy and carbon-intensive, currently producing between 25% and 40% of global carbon emissions. Around 8% of the overall global CO2 emissions come from the production of steel and concrete, for example.
Mining, processing and production of iron and steel is highly energy-intensive and causes air pollution in the form of nitrous oxide, carbon dioxide, carbon monoxide and sulphur dioxide.
Brick manufacturing
Cement is the major component of concrete, solely responsible for 5-7% of the total anthropogenic carbon emissions. Brick manufacturing is another mainstay of the construction sector.
Despite contributing a healthy 1.5% to the country’s gross domestic product, at the same time it enormously adds to the air pollution, especially around urban areas.
Brick production in Pakistan follows traditional brick-firing technology widely used in South Asia that consists of handmade bricks, which are baked in the Fixed Chimney Bull’s Trench Kilns (FCBTK).
This is one of the most contaminating techniques for brick production. This method results in a range of environmental impacts including air pollution, climate change and health hazards. Fuels in these traditional brick kilns include coal, furnace oil and all sorts of garbage like used tyres, rubber and plastics. All these types of fuels burnt make a mix of air pollutants emitted by the sector including sulphur, nitrogen and carbon oxides, forms of particulate matter including black carbon, and additional harmful compounds.
In recent years a few studies, including the one by this writer, have been conducted to assess the scope for new techniques of brick production.
Skat Consulting, with financial assistance from the Swiss Agency for Development and Cooperation (SDC), started implementing a project for technology transfer in Pakistan with the aim of piloting and demonstrating environment-friendly construction materials and technologies, in particular the introduction of Vertical Shaft Brick Kiln (VSBK) technology.
The VSBK technology, which originated in China, is a brick manufacturing system which is far more energy-efficient and environment-friendly than most of the traditional systems, hence reducing air pollution in urban settings.
The technology has become a great success in Nepal and two pilot kilns have been established on the outskirts of Islamabad, however, it has yet to take off commercially in the country. With enormous demand expected in the near future, it is time that such initiatives are given serious impetus.
Impact of environment
Besides construction having its susceptible effects on climate change, the state of environment has its own impact on construction work including raw material, supply chain, processing and output, ie infrastructure and buildings. Durability and sustainability of buildings and structures is primarily dependent on environmental conditions. The current government has both construction as well as climate change among its priorities, however, surprisingly its national housing policy does not include and address the climate change and environment element per se.
In Pakistan, construction projects are undertaken by the public as well as private sectors with the latter leading the volume.
Whereas for public sector development projects, there exists a mechanism to assess the environmental impact before giving the green light to projects, the private sector has not been educated and sensitised enough to take this important factor into account.Construction and building laws and bylaws, even that do exist, are commonly evaded through a lack of strict compliance, implementation lacunae, malpractices and governance issues.
Now that a huge construction and housing initiative is to be implemented in coming years, it is imperative that the climate factor is aptly assessed and coordinated. A concerted effort has to be made by all the stakeholders belonging to both these spheres in sync for ensuring sustainability.
A departure from traditional production, processing, storage, design and planning is the need of the hour.
As many developed and some developing countries have already started, it is necessary that private sector builders are educated about the global climate commitment, for example the Paris Agreement, and facilitated to meet such obligations.
While planning new construction projects, sites may be selected in such a manner that forestry and agriculture are harmed minimally. Besides, it may be made obligatory through legislation that natural resources depleted due to construction activity are compensated by the builders.
