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Concrete in numbers before the planet
These days, the famous newspaper The Guardian, celebrates the «Concrete Week». Where the aesthetic and social achievements of the concrete (See concrete houses), and in turn, they also investigate the innumerable damages that concrete has produced and will produce to try to understand its repercussion and what possibilities we have towards a less gray world.
Today, it is time to shell concrete in numbers at a global level to understand its impact. And what better way to start by reviewing an article published by Jonathan Watts (See Ref. 1 - The Guardian Article). It has no waste, and starts with …
In the time it takes to read this sentence, the global construction industry will have poured more than 19,000 concrete buckets
By the time I am in the middle of this article, the volume will fill Albert Hall and spill over into Hyde Park. In one day it would be almost the size of China's Three Gorges Dam. In a single year, there is enough to build a patio on every hill, valley, nook and crevice in England.
Although there is some debate about when and where the first concrete was used. The truth is that the Romans were the first to use concrete the way we do today.
Later, the invention of reinforced concrete gave the material a new life. It was pioneered in France (mid-19th century), but was popularized by the Californian engineer Ernest Ransome, who poured over iron (and later steel) bars to improve their tensile strength.
Since then, after water, concrete is the most widely used substance on the planet. But its benefits hide enormous dangers for the environment as we have already related in our blog, for human health and for the culture itself.
How much concrete is produced globally?
The cement, the key component of concrete and one of the materials most used by man, it is now the cornerstone of global construction. It has shaped the modern environment, but its production has a massive footprint that neither industry nor governments have been willing to address.
More than 4 billion tons of cement are produced each year, representing around 8% of global CO2 emissions.
Actually, if we look at the latest Chatham House report (See Ref. 2) that investigates the innovation of low carbon cement and concrete. The numbers are impressive!
Each year more than 4,000 million tons of cement are produced, which represents around 8% of global CO2 emissions. If it were a country, the cement industry would be the third largest in the world, only behind China and the United States.
And if we compare. All the plastic produced in the last 60 years amounts to 8,000 million tons. We complain a lot about plastic! … That amount of concrete is manufactured every two years.
All the plastic produced in the last 60 years, amounts to 8,000 million tons. That amount of concrete is manufactured every two years.
Following the trajectory of the report A blueprint for a climate friendly cement industry (Report issued by WWF - See Ref. 3). World cement production will increase to more than 5 billion tons per year in the next 30 years.
Why is demand increasing so much?… Rapid urbanization and economic development in regions such as Southeast Asia and Sub-Saharan Africa will increase the demand for new buildings, and therefore for concrete and cement.
With up to 3 billion people who could need a home by 2050, new housing solutions are urgently needed, especially in emerging economies.
And not only housing, infrastructure is needed, the need to build dams, roads, water supply, sanitation, energy services or the increase in personal wealth, have fueled the demand for concrete material.
Its carbon footprint is so large that unless it is transformed and made to adopt cleaner practices, the industry could, on its own, jeopardize the entire 2015 Paris agreement.
Let's remember COP21, whose objective is to keep world temperatures below 2 degrees Celsius. To put it in line, the UN says its annual emissions need to be cut by 16% over the next 10 years, and much more in the future.
Although some of the older cement companies They have reduced the carbon intensity of their products by investing in more fuel efficient kilns, most of the improvements achieved have been overshadowed by the massive increase in global cement and concrete production.
Who consumes the most concrete worldwide?
Currently, the reality is that, with more population, more consumption of cement and concrete. So we can already intuit who is at the forefront of reproducing more cement worldwide.
And yes also, they like to build infrastructure in a big way. We just have to head to China!
China already houses the world's largest concrete structure: The Three Gorges Dam across the Yangtze River. China's "new Great Wall" and its hydroelectric power station is the largest in the world in terms of capacity.
Beijing's new airport is just the latest megaproject that has seen China pour more concrete every two years than the United States in the entire 20th century.
The international airport, nicknamed "the starfish" coined by the architecture studio Zaha Hadid Architects, will open in October and could handle more than 100 million passengers a year.
These ambitious infrastructure projects require an immediate and ample supply of concrete. It is a demand that has been easily satisfied by the country's supply of cement: in 2022, China produced 2.4 billion tons of this material, more than the rest of the world as a whole (See Ref. 4).
China produced 2.4 billion tons of this material, more than the rest of the world combined
How much water do you consume globally?
Previous studies on environmental impacts of concrete production They have mainly focused on the materials involved and the energy consumption.
While some voices are raised announcing that the gold of the future will be drinking water. Concrete is a thirsty giant, which is responsible for 9% of industrial water withdrawals worldwide.
Concrete is responsible for 9% of industrial water withdrawals worldwide
It is estimated that (See Ref. 5), in 2050, 75% of the demand for water for concrete production will probably occur in regions affected by drought and water stress.
How can you reduce the effects of concrete?
The cement sector it faces a major expansion at a time when its emissions must decline rapidly.
To understand how to reduce it, we must first look at the cement manufacturing value chain:
From a technical point of view, there are several solutions to reduce the emissions associated with the cement productionor; all of them will need to be deployed at scale to meet the challenge of decarbonization.
Some of these solutions are well recognized and common to other sectors: for example, the energy efficiency of cement plants can be increased, fossil fuels can be replaced by alternatives, and the CO2 emitted can be captured and stored.
The following scheme simplifies emissions and mitigation solutions throughout the cement supply chain:
However, the main focus is to focus on those emission mitigation solutions that require the transformation of cement and concrete, and which are therefore unique in the sector.
More than 50 percent of emissions from the cement sector are intrinsically related to the clinker production process, one of the main ingredients of cement. Therefore, reducing the need for clinker and mixing it with alternative materials will be an important avenue.
Let's remember the article about a stronger and more ecological concrete thanks to carrots.
It will also be essential to abandon the use of fossil fuels in cement productionor. China and India, in particular, have significant potential to switch to sustainable low-carbon fuels.
In Europe, it has been shown that cement plants they run on 90% non-fossil fuels. A key challenge will be to ensure the availability of biomass from truly sustainable sources.
The European Union, in its report A sustainable future for the European cement and concrete industri (See Ref. 7). It proposes a roadmap for decarbonization focused on three key points:
- Use cutting-edge technologies.
- Efficient use and recycling.
- Structural optimization and principles of circular economy (See article on what is circular economy).
The report shows that by considering all stages of the value chain, it is possible to achieve reductions of up to 80% in CO2 emissions, compared to the 1990 values, being achievable by 2050.
The barriers to deep decarbonization of cement
- The sector is dominated by a handful of large producers, who are cautious about pioneering new products that challenge their existing business models.
- There are few short-term economic incentives to make changes in the cement sector.
- Architects, engineers, contractors, and clients are understandably wary of new construction materials.
- The implementation of new practices also implies a critical role for millions of workers involved in the use of concrete throughout the urban landscape.
As a recent report (Zero Carbon Industry Plan Rethinking Cement from Australia) points out …
When cement emissions are mentioned in public debate, it is typically to point out that little can be done about it.
Concrete can take our civilization to the top, 163 stories high if we look at the tallest skyscraper in the world Burj Khalifa in Dubai. But it also pushes the human footprint, spreading through fertile land and suffocating habitats.
The biodiversity crisis, with the terrestrial and aquatic ecosystems in decline - which many scientists consider a threat as great as climate chaos - is mainly due to the conversion of natural spaces in the face of intensive agriculture, industrial estates and blocks of households.
For hundreds of years, humanity has been willing to accept this environmental disadvantage in exchange for the undoubted benefits of concrete. But the balance may now be tipping in the other direction.
Bibliographic references:
- Article The Guardian (Concrete: the most destructive material on Earth).
- Chatham House Report (Making Concrete Change: Innovation in Low-carbon Cement and Concrete).
- Report issued by WWF (A blueprint for a climate friendly cement industry).
- Article on cement production in China (Via Forbes)
- Nature report (Impacts of booming concrete production on water resources worldwide)
- Recent report from Australia (Zero Carbon Industry Plan Rethinking Cement).
- How stamped concrete is made
- U. Europea report (A sustainable future for the european cement and concrete industri).
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