Concrete is the most widely used artificial material in history. Only water surpasses it as the most consumed resource on the planet.
But even though cement – the most important ingredient in concrete – has shaped a lot of the surrounding structure, it also leaves a large coal track.
It is source of about 8% of emissions of carbon dioxide (CO2) in the world, according to the British study center Chatham House.
If the cement industry was a country, it would be the third largest emitter in the world, behind China and the United States It emits more carbon dioxide in the atmosphere than aviation fuel (2.5%) and is not far from agricultural agriculture (12%).
The cement industry leaders participated in these days UN Conference on Climate Change, COP24, heldor in Poland, to find a way to meet the requirements of the Paris agreement.
According to the Pact's annual emissions of cement they should fall at least 16% from here until 2030.
Advantages of concrete
For those who hate it, concrete, as an important material in most buildings, parking lots, bridges and ponds have allowed the construction of some of the Worst architectural monster in the world.
In the United Kingdom, it contributed to the tremendous development after World War II, but today it still raises shared views.
But concrete is also the reason why some of the world's most impressive buildings owe their existence.
the orpears in Sydney, in Australia, the Lotus Temple in Delhi, India, Burj Khalifa in Dubai, United Arab Emirates, or the magnificent Pantheon in Rome, Italy, which has the largest unsupported concrete dome in the world. Everyone owes their shape to this material.
Constructed with a mixture of sand and gravel, a conglomerate of cement and water, concrete is universally accepted by architects and builders who one of the best building materials.
"It is affordable, it can be produced almost anywhere and has all the right structural features to build a sustainable building or infrastructure, "explains Felix Preston, Deputy Research Director at Chatham House Department of Energy, Environment and Resources.
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And it is despite the known problems of durability using steel reinforcement that can crack the concrete from the inside, The concrete is still the most widely used material in the world.
"It's a challenge to build without it, even if it's possible," says Preston.
The growth of the cement industry
These unmatched concrete designations have contributed to increasing global cement production since the 1950s. In this unavoidable upturn, Asia and China represent the bulk of growth since the 1990s.
the production has increased in more than thirty times since 1950 and almost four times since 1990. China used more cement between 2011 and 2013 than the USA throughout the 20th century.
Now that Chinese consumption seems to stabilize, it is expected that most of the future growth of construction will occur in the emerging markets of Southeast Asia and sub-Saharan Africa, driven by rapid urbanization and economic development.
Forecasts show that the world's built-up areas will double over the next 40 years, which means that cement production will increase by 25% by 2030.
However, despite its widespread presence, the environmental impact of concrete has been the subject of further analysis in the past two decades.
Portland cement production, the most common type, not only involves stone mining in quarries, which pollutes the air through dust emissions, but also requires the use of huge ovens that consume large amounts of energy.
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the chemical process of cement manufacture It also emits incredibly high levels of carbon dioxide.
The sector has made progress: the improvements in the energy efficiency of fossil fuels and the substitution of fossil fuels for waste incineration have resulted in average carbon dioxide emissions per tonne of production having fallen by 18% in recent decades, according to Chatham House.
The recently established Global Cement and Concrete Association (GCCA), as currently represents about 35% of cement production capacity of the world focusing on sustainable development, participate in COP24 meetings.
The organization's CEO, Benjamin Sporton, says that the fact that the organization has recently existed is "a demonstration of industry's commitment with sustainability, including adoption of measures against climate change ".
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GCCA has to publish a set of sustainability guidelines that its members must follow.
"By bringing together global actors to find focus and develop a detailed work program, we can help guarantee a sustainable future for cement and concrete, and for future generation needs, "says Sporton.
But despite promises, Chatham House reminds that the industry reaches the limits of what it can do with current actions.
If the sector has any hope of meeting its commitments reflected in the Paris Climate Change Agreement of 2015, it should review cement production, not only reducing the use of fossil fuels.
Clínker, the biggest pollution
It is the clinker production process, the most important component of cement that is formed after calcination of limestone and clay, which produces the largest amount of carbon dioxide in the production.
In 2016 global cement production generated 2 200 million tonnes of carbon dioxide, which corresponds to 8% of the world's total. More than half came from the calcination process.
Together with thermal combustion, 90% of the sector's emissions can be attributed to clinker production.
Because of this, the Chatham House expert claims that the industry urgently needs to follow a series of strategies for reducing carbon dioxide emissions.
Further efforts with regard to energy efficiency, reduced use of fossil fuels and coal search and storage will help, but in isolation they can do a little.
"We have a long way to close the gap," said Preston.
What the industry really needs to do is to strengthen efforts produce new types of cementHe says.
The fact is the development of carbon dioxide cement and new types of cement could eliminate the use of clinker completely.
Ginger Krieg Dosier, co-founder and CEO of BioMason, a company like uses triljar of bacteria to manufacture concrete stones, is one of the companies trying to get more support for alternative cement.
The technique, which involves placing sand in molds and inject it with microorganisms, initiates a process similar to that created by the coral.
"I was always fascinated by cement and marine structures," explains Krieg Dosier, who began investigating alternative manufacturing of bricks with respect for nature 10 years ago.
Her discoveries led her to create her own material, which after four years of development only requires four days to manufacture.
The process is done outdoors, without the need for fossil fuels or calcination, two of the most important sources of carbon dioxide emissions from the cement industry.
Krieg Dosier believes that "green" cement and techniques like the one she has developed offer a solution to the problem of emissions of sectors.
"Traditional Portland cement production continues to release CO2 due to the chemical process behind it," he says, adding that instead of resorting to carbon capture and storage, we should invest more in technicians who actively remove carbon from the atmosphere.
"Alternative cement and conglomerate technology goes beyond CO2 capture."
"Transformation of forces"
Along with alternative cement, other "transformative" forces begin to make changes. Digitization, machine learning and increased awareness of sustainability have an impact on the cement industry's culture.
"Partly change due to how people want to live, but also our ability to design new structures and innovative and test them with calculation models, "said Preston. "There is also the opportunity to build cheaper things with robots, using automation."
But changing processes that are fast enough to meet the cement industry's obligations is a challenge.
The sector is dominated by a small number of producers that are reluctant to change the business model. Architects, engineers, contractors and customers are also careful about the use of new materials in buildings.
"This sector, which is difficult to change, begins to collide with these deep transformations as we begin to see in construction," says Preston.
However, as very few carbonic acids reach the stage of commercialization, and no one applies to the scale in the industry, it seems likely that still necessary state aid over time.
If governments do not run the industry or provide money, it may not be possible to see next-generation cement on the market within the required timeframe.
But Krieg Dosier believes there are reasons for optimism.
"I think the construction industry is approaching a point there The alternative materials will generalize their assumptionhe says.
"This is due, inter alia, to market demand, the emergence of other innovative technologies and increased concern for climate change."
Preston says it is imperative that governments and industry act quickly in a time when global development is expected to increase but carbon dioxide emissions are decreasing.
"There is an urgent need to build quality and affordable housing"He says.
"There is a need to have new infrastructures, we can only square this circle if we can exponentially improve how we build so that these Buildings are constructed in general, with net emissions as close as possible to zero".
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