Climate Change

COP27: Carbon emissions, energy consumption due to constructions back to pre-COVID levels

Report reveals 10 gigatonnes of carbon dioxide emitted in the atmosphere in 2021; Most significant energy demand in last 10 years

By Seema Prasad
Published: Friday 11 November 2022
A lull in emissions was recorded in 2020 when the construction sector had temporarily come to a halt. Photo: Wikimedia Commons

Carbon emissions and energy consumption in the buildings and construction sector rebounded to pre-COVID-19 pandemic levels in 2021, a new report has shown. 

Around 10 gigatonnes of carbon dioxide (CO2) were emitted into the atmosphere in 2021 by the construction sector, according to the 2022 Global Status Report for Buildings and Construction. The report was released November 9, 2022, at the 27th Conference of Parties (COP27) to the United Nations Framework Convention on Climate Change at Sharm El-Sheikh, Egypt.

This is equivalent to a 5 per cent increase from 2020 levels, exceeding the last peak in 2019 by 2 per cent, the report said. 

Read more: Technology advancement not matching energy demand, leading to emissions: report

2021 also saw the most significant increase in energy demand in the buildings sector in the last ten years at 135 exajoules, as per the data from intergovernmental organisation International Energy Agency, quoted by the report. 

A lull in emissions was recorded in 2020 when the construction sector had temporarily come to a halt, but the study reveals a rebound back to pre-pandemic levels.

The report said: 

Energy is consumed in the form of electricity and gaseous, liquid and solid fuels and district energy for building energy uses (eg heating, cooling, cooking, lighting and equipment) and is responsible for around 27 per cent of global operational-related CO2 emissions (10 GtCO2). 

The production of materials used in the construction of buildings, including steel, aluminium, concrete, glass and brick, when combined with CO2 emissions, “account for around 37 per cent of global energy and process-related emissions.”

Net Zero Emissions

The energy intensity of buildings is currently at 150 kilowatt hours per square metre (kWh/m2). However, a 35 per cent drop to 95 kWh/m2 at a rate of 5 per cent per year by 2030 is needed to achieve Net Zero, the IEA projected.

“The building renovation rate must increase to 2.5 per cent per year (or 10 million dwellings per year) by 2030 in developed economies alongside decarbonisation of the grid for Net Zero,” the IEA said in a 2021 study. 

A higher reduction of emissions at 95 per cent was quoted by the Sixth Assessment Report of the United Nations Intergovernmental Panel on Climate Change. 

Read more: Cities and climate change: why low-rise buildings are the future – not skyscrapers

There is “a growing gap between the actual climate performance of the sector and the necessary decarbonisation pathway,” according to the 2022 update of Global Buildings Climate Tracker. The tracker monitors the progress of the buildings and construction sector toward achieving the Paris Agreement. 

The number of countries that referred to buildings-related emissions in their Nationally Determined Contributions (NDC) grew from 69 per cent in 2020 to 80 per cent in 2021. Furthermore, around 23 countries updated their NDCS with policies showing increased commitment to building efficiency and adaptation.

Building Codes

Energy codes set the standard for energy usage and emissions of a new or renovated building. “As of September 2022, 40 per cent of countries have mandatory or voluntary regulations or codes for building energy performance,” the report said. 

However, this mostly refers to commercial buildings. When the authors studied energy codes and regulations for residential and non-residential buildings, only 26 per cent of countries had them.

“In 2021, seven US states adopted more stringent building codes for enforcement, including Washington and New York states, which have focused on promoting electrification and the use of heat pumps, and geothermal heating and cooling systems,” the report said. 

Only 9 per cent of African countries have a compulsory building code. 

Report’s recommendations

There’s an opportunity to recycle materials and reduce emissions when the demand for raw materials is touted to double by 2060 as the world’s economy grows, according to United Nations’ International Resource Panel. 

“In Group of Seven (G7) countries alone, material efficiency strategies, including the use of recycled materials, could reduce greenhouse gas emissions in the material cycle of residential buildings by over 80 per cent in 2050,” the report said.

Read more: ‘The Earth is revealing the carbon cycle to modern science’

In another solution, the potential of embodied carbon, which refers to the ‘whole life cycle’ of materials used in building construction and the greenhouse gas emissions associated with them, was highlighted by the analysis. 

A whole life cycle approach consists of “measures ranging from building less, requiring less material and using low-carbon materials, to circular approaches and improved designs that have a longer lifetime and lower operational emissions during building use.”

“To decarbonise the building materials sector, all stakeholders need to take greater responsibility to understand the environmental impact of their decisions regarding material selections across the life cycle. Doing so requires getting the right data to the right stakeholders at consequential stages of decision-making,” the report recommended. 

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