We-Building not only carries out construction of schools and public buildings in Africa and Latin America, but also focuses on educational work on sustainable building.
This is because not enough people are aware that conventional construction and unsustainable use of buildings lead to serious problems for people and the environment worldwide.
Most are surprised when we explain the construction industry is responsible for 38% of CO2 emissions globally while the airline industry only emits 3%, a statistic from the United Nation’s “2022 Global Status Report for Buildings and Construction”. The most common response we hear is “I didn’t know that”, often followed by, “there’s nothing we can do about it, we need houses.”
Indeed, we all need a roof over our heads. In our temperate climate zone alone, an estimated 80-90% of our lives are spent indoors (Deutsche Gesellschaft für Nachhaltiges Bauen, 2020). Living, learning, working, meeting up and having fun, that’s what 8 billion people in this world – the entire global community – wants. To meet that enormous need requires more buildings, with many more in the future. Fortunately, it’s not true that “there’s nothing we can do”.
This “do nothing” mentality is not only wrong, but also fatal because:
The construction industry …
- Is the main driver of climate change due to the highest CO2 emissions of all global industries
- Is responsible for an enormous consumption of raw materials and production of high levels of non-recyclable waste with damage to life on land (ecosystems, biodiversity)
- Is, in industrialized countries, responding to the desires of wealthier populations and has led to a ‘construction boom’ at the expense of those in poverty, especially in the Global South, resulting in human rights violations, food insecurity, energy injustice, among others
- Consumes very high amounts of electricity, water, heating, and cooling energy in the manufacturing of building material, which come predominantly from fossil energy sources, with negative effects on the climate that disproportionately affects the Global South (droughts, storms, floods and negative public health consequences).
The building boom and climate change
Even though all these problems have existed for many years, the situation has become more pressing than ever. There has been a global increase in construction activity, and the construction industry is booming. In Germany alone, around 2.5 million people work in the construction and finishing trades, in more than 330,000 companies. (Statistisches Bundesamt, 2020) Even during the peak of the COVID pandemic in 2020, the world’s top 100 largest construction companies had a combined revenue of 1.5 trillion US dollars, growing by 3.7 percent.
The highest CO2 emissions are attributable to cement and steel. Cement – the binder in concrete – accounts for 8% of greenhouse gas emissions during production. Research is being carried out into alternatives, but none of the technologies are yet proven and ready for use or affordable for the global market. Around one third of steel is produced for the construction sector. In reinforced concrete, it is one of the most widely used modern building materials. In addition, steel beams and plates are also used. The enormously high temperatures involved in steel produced by fossil fuels, as well as chemical reactions when iron ore is mixed with coal, cause around 10% of global CO2 emissions. Because steel will not be completely dispensed with in construction, low-emission fuels and in the search for “green steel” play an important role.
In many regions of the world, the high consumption of concrete is leading to a shortage of basic concrete materials of sand and gravel in the required quantity and quality. This constant extraction of sand and gravel can affect biodiversity, pollute water bodies and groundwater, and change the water table and the landscape. In Indonesia, sand mining has already led to the complete disappearance of some islands. Sand mining of riverbeds in China and African countries is causing rivers to dry up and farmers to be displaced.
The global construction boom (especially in China, the USA and other industrialized countries) is still being implemented with conventional building materials, like concrete and steel. This is driving environmental pollution and climate change. In the USA alone, 822,000 newly built single-family homes were sold in 2020. (U.S. Census Bureau) The construction of single-family housing estates on newly developed land on the outskirts of large cities means that new infrastructure (electricity, water, sewage, roads, etc.) is created at great expense for a privileged few. Deforestation takes place, and biodiversity is destroyed.
The dream-home desires of the wealthy also triggers a chain of problematic consequences. Single-family homes harm the environment because they take up large areas of previously undeveloped land. Paved surfaces seal away natural soil, which means that the soil can no longer absorb and store rainwater. The water seeps away into the drainage, resulting in a long-term lack of groundwater and a higher risk of flooding during heavy rains. The local climate heats up from the surface pavement, creating an urban heat island effect.
Overexploitation of resources and land
The construction sector consumes an enormous amount of raw materials – around 50% of the raw materials taken from nature are used in the construction industry. As a result, the environment and climate are polluted worldwide – and disproportionately so in the Global South.
The construction industry also accounts for 50% of the waste generated in Germany (including demolition waste). Demolition materials are recycled – if at all – in an inferior manner and a large proportion becomes non-recyclable waste that pollutes the soil.
The construction sector is dependent on raw material imports from the Global South for the production of various building materials. In some cases, the extraction of raw materials has extremely negative effects on people and their environment. Human rights violations and environmental pollution with serious consequences for human health can result.
Take copper, for example – this metal is needed for roofs and gutters, facades, and pipes for tap water and heating systems. One of the world’s largest copper producers is Zambia. Copper mining in this resource-rich but income-poor country in southern Africa provides revenue and jobs, but also has a strong negative impact on the environment and human rights. Communities near mine sites struggle with poor water quality and health problems. Forced relocations and the destruction of local agriculture occur repeatedly as part of the construction of new mines. This has a negative impact on food security in local communities. Farmers harvest lower yields due to soil and water contamination or lose their livelihoods altogether due to forced relocation.
Disproportionately high energy consumption
Construction consumes a lot of energy. The energy used for industrial production and material transport, as well as the electricity, heating and cooling energy used in buildings, is predominantly obtained from fossil energy sources. The “gray energy” that is generated during the production, transport or storage of building materials, among other things, is enormous.
CO2 emissions are disproportionately caused in the Global North, but the environmental consequences (including droughts and famines) impact communities in the Global South.
For example, the European Union and North America regions, led by the United States, accounted for about 35% of global CO2 emissions in 2021. In contrast, the entire African continent is responsible for only 3.6%. (Ritchie et al., 2020) Germany contributes about 2%. For average per capita consumption of carbon dioxide, Germany is far ahead of others. In 2020, each of the 83 million inhabitants in this country consumed an average of 11.6 tons of CO2. In contrast, the Democratic Republic of Congo, with 86 million inhabitants, consumed only 0.04 tons per individual.
What can we do?
This overview of the global building industry is to illustrate the serious damage being done to the climate, environment, and human well-being. Not only can we make progress towards a better future by being aware of the facts, but we can also enact change now. What can be done, and what is already being done to make construction more climate-friendly? Our next blog post, “Climate-friendly building is possible” will be about this topic.
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- Deutsche Gesellschaft für Nachhaltiges Bauen. (2020). Bauen für eine bessere Welt. https://www.dgnb.de/de/aktuell/pressemitteilungen/2020/dgnb-report-sdgs
- Key figures in the construction industry, 2020. (2020). Statistisches Bundesamt. https://www.destatis.de/EN/Themes/Economic-Sectors-Enterprises/Construction/Tables/key-figures-construction-industry.html
- United Nations Environment Programme. (2022). 2022 Global Status Report for Buildings and Construction: Towards a Zero‑emission, Efficient and Resilient Buildings and Construction Sector. Nairobi. https://globalabc.org/our-work/tracking-progress-global-status-report
- US Census Bureau. (2022). New residential sales. https://www.census.gov/construction/nrs/index.html
- Ritchie, H., Roser, M., & Rosado, P. (2020). CO₂ and greenhouse gas emissions. Our World in Data. https://ourworldindata.org/co2-and-greenhouse-gas-emissions