Construction is the world's biggest polluter. Often, when we talk about pollution, the images that come to mind are those of smoking chimneys, traffic jams or sprawling livestock farms. We rarely think about the impact of the buildings around us, the concrete that makes up our homes, offices and cities.
Yet construction, that silent giant, is the main culprit of global CO2 emissions, contributing a staggering 37% to global pollution, a figure that dwarfs sectors traditionally singled out as the main environmental villains.
This figure, although alarming, is not usually a topic of conversation. We worry about the energy efficiency of our appliances, the carbon footprint of our food, even the impact of the clothes we wear. But how often have we stopped to think about the environmental cost of the buildings we live in, the infrastructure we use every day?
All around us, in a never-ending cycle, new buildings are being built: homes, offices, shopping centres, warehouses… a testament to our development, but also an indelible mark on the planet.
The problem lies in the two fundamental pillars of construction: cement and steel. Cement production, for example, involves the calcining of limestone at high temperatures, a process that releases huge amounts of carbon dioxide into the atmosphere. On the other hand, the manufacture of steel, although recyclable, also involves high energy consumption and the emission of greenhouse gases. Together, these two materials form the basis of most modern constructions, perpetuating a cycle of high pollution that often goes unnoticed.
It is true that the construction industry is not a monolithic monster. There are increasingly relevant efforts to develop more sustainable alternatives. Research is being done to create cements with a lower carbon footprint, using recycled materials and exploring new production processes. Progress is also being made in the production of green steel, using hydrogen as an energy source instead of coal, which drastically reduces emissions.
However, despite these encouraging advances, we are still a long way from a real transformation of the sector. The production of these “green” materials remains expensive and their large-scale implementation faces significant technological and economic challenges. Today these materials are not “green” at all.
Why then, despite its impact, does construction not receive the same attention as other polluting sectors? One of the main reasons is its intricate relationship with economic growth. Construction is a vital economic engine for virtually every country in the world. It generates employment, drives demand for materials and services, and stimulates investment.
When a building is built, it is not only the construction companies and the workers directly involved that benefit, but also a wide network of auxiliary industries: from furniture and appliance manufacturers to transport and logistics companies. This multiplier effect makes construction a strategic sector for governments, which often prioritise short-term economic growth over long-term environmental sustainability.
Another factor that contributes to the invisibility of the environmental impact of construction is the difficulty in quantifying it and attributing it to a specific actor. While the emissions of a car or a factory are relatively easy to measure and control, the carbon footprint of a building is diluted among multiple actors: from the manufacturer of the materials to the end user. This complexity makes it difficult to implement effective policies and assign responsibilities.
So what can we do? The solution is not simple and requires a multifaceted approach. Firstly, it is essential to raise awareness of the environmental impact of construction, both among professionals in the sector and among the general population. We need to demand more sustainable buildings, built with recycled materials and with a design that minimizes energy consumption.
In addition, it is crucial to promote research and development of alternatives to traditional cement and steel, as well as to encourage the implementation of more efficient construction practices.
Governments, for their part, must play an active role in the transition to more sustainable construction. It is necessary to implement policies that encourage the use of low-carbon materials, that promote the rehabilitation of existing buildings and that penalize polluting construction practices.
Construction, that silent giant, must stop being one. It is time to recognize its environmental impact and take concrete measures to transform it into a more sustainable sector. The future of our planet depends on it.
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