EFE
The housing construction sector needs to convert existing buildings and use more bio-based materials, such as wood and bamboo, to reduce its growing CO2 emissions, which already account for 37% of the global total, a UN report released Tuesday said.
The report, produced by the UN Environment Programme (UNEP) and the Yale Center for Ecosystems + Architecture (Yale CEA), highlighted that globally urbanization is advancing so rapidly that every five days as many buildings are constructed worldwide as already exist in Paris.
This rate of construction is causing the construction sector to be responsible for 37% of all global carbon dioxide emissions, although that proportion is increasing.
Sheila Aggarwal-Khan, director of UNEP's Industry and Economy Division, stated that emissions are partly increasing because in many countries traditional building materials are being replaced by others with a higher environmental cost.
"Until recently, most buildings were constructed using local materials such as earth, stone, wood and bamboo," he explained when presenting the report.
"But modern materials like cement and steel often only give the illusion of durability and end up in landfills, contributing to the growing climate crisis," Aggarwal-Khan added.
Three-front strategy
The report, which falls under the mandate of the Global Alliance for Buildings and Construction (GlobalABC), a platform created at COP21 with 298 members, 40 of which are countries, to achieve the goal of zero emissions in the sector, suggests a three-pronged strategy for eliminating CO2.
- First, avoid waste by retrofitting existing buildings, which reduces emissions by 50 to 75% compared to constructing new structures. At the same time, it is necessary to promote construction using fewer materials and those with a lower environmental impact.
- In this regard, the second proposal of the report's authors is the replacement of materials such as cement, steel and aluminum with renewable and biological products, such as wood, bamboo and biomass.
Experts estimate that the replacement could accumulate savings of up to 40% of the sector's emissions in many regions of the world by 2050.
- And finally, the report points out that when materials cannot be replaced by renewable and biological alternatives, it is necessary to improve the production process of cement, steel, aluminum, glass and bricks.
The production of cement, steel, and aluminum for building construction aloneaccounts for 23% of global carbon dioxide emissions.
To decarbonize the production of these construction materials, it is a priority to use electricity from renewable sources, increase the use of recycled materials, and use innovative technologies.
In this regard, the authors said in a statement, if future building materials come from the carbon capture process, buildings could even be "carbon negative," meaning they would not only not contribute to CO2 emissions but would participate in their removal from the atmosphere.
Aggarwal-Khan, one of the researchers, believes that if governments implement "appropriate policies, incentives and regulations" following these guidelines, the construction sector can achieve zero emissions by 2050, according to the statement.
Anna Dyson, the report's lead author and founding director of Yale CEA, added that "policies must support the development of new models of cooperation around the construction, timber and agricultural sectors, to galvanize a just transition to circular economies based on bio-based materials.".
Until now, the study added, most policies andinitiatives in the sector have been aimed at reducing emissions from building operations, such as heating, cooling or lighting.
These initiatives have been successful, as it is expected that the measures underway will reduce emissions from building operations by between 50 and 75%.
Photo: buildings in Santo Domingo.
