UN: CO2 emissions from buildings and construction hit new high

The United Nations has said CO2 emissions from buildings and construction have hit a new high leaving the sector off track to decarbonise by 2050

Despite an increase in energy efficiency investment and lower energy intensity, the building and construction sector’s energy consumption and CO2 emissions have rebounded from the COVID-19 pandemic to an all-time high.

Released at the latest round of climate talks in Egypt, COP27, the 2022 Global Status Report for Buildings and Construction finds that the sector accounted for over 34% of energy demand and around 37% of energy and process-related CO2 emissions in 2021.

The sector’s operational energy-related CO2 emissions reached ten gigatonnes of CO2 equivalent – 5% over 2020 levels and 2% over the pre-pandemic peak in 2019. In 2021, operational energy demand for heating, cooling, lighting and equipment in buildings increased by around 4% from 2020 and 3% from 2019.

This, according to the report from the Global Alliance for Buildings and Construction (GlobalABC), means that the gap between the climate performance of the sector and the 2050 decarbonisation pathway is widening.

Inger Andersen, executive director of the United Nations Environment Programme (UNEP), said: “Years of warnings about the impacts of climate change have become a reality. If we do not rapidly cut emissions in line with the Paris Agreement, we will be in deeper trouble.”

“The buildings sector represents 40% of Europe’s energy demand, 80% of it from fossil fuels. This makes the sector an area for immediate action, investment, and policies to promote short and long-term energy security.”

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avoiding CO2 emissions

Decarbonising the buildings sector by 2050 is critical to delivering these cuts. To reduce overall emissions, the sector must improve building energy performance, decrease building materials’ carbon footprint, multiply policy commitments alongside action and increase investment in energy efficiency.

Despite some positive results, growth is still outpacing efforts on energy efficiency and reducing energy intensity.

The report says that investments in energy efficiency must be sustained in the face of growing crises – such as the war in Ukraine and the ensuing energy crisis, and the cost-of-living crisis – to reduce energy demand, avoiding CO2 emissions and dampen energy cost volatility. The buildings sector is therefore an area for immediate action, and the report shows that the sector can still change.

For example, rising fossil fuel costs due to the war in Ukraine and the cost-of-living crisis are providing incentives to invest in energy efficiency – although the erosion of purchasing power and the impact of labour and materials may slow investment.

Andersen added: “The solution may lie in governments directing relief towards low and zero-carbon building investment activities through financial and non-financial incentives.”

mandatory building energy codes

Also critical to reducing the sector’s emissions are including buildings in climate pledges under the Paris Agreement – known as Nationally Determined Contributions (NDCs) – and mandatory building energy codes.

The number of NDCs that mention buildings grew from 88 in 2015 to 158 in 2021. However, progress on buildings and construction policies and action remains slow. Over the same period, the number of countries with building energy codes rose from 62 to 79. However, only 26% of countries have mandatory building energy codes for the entire sector.

Raw resource use is predicted to double by 2060 – with steel, concrete and cement already major contributors to greenhouse gas emissions. Materials used in the construction of buildings already account for around 9% of overall energy-related CO2 emissions.

Embodied carbon in buildings – the emissions associated with materials and construction processes – needs to be tackled to avoid undermining energy-saving measures. However, the sector can reduce its impact by, for example, looking at alternative materials and decarbonising conventional materials such as cement.

particular relevance for Africa

The report states there is a particular relevance for the African continent where the African population is expected to reach 2.4 billion people in 2050 and 80% of this growth will occur in cities. An estimated 70% of the African building stock expected for 2040 has yet to be built.

To avoid increasing emissions while building the stock necessary to move people out of informal settlements, and to create buildings that are resilient to the impacts of climate change, the African sector should look at sustainable construction materials and design techniques, in which the continent is rich.

The report maintains that Africa is also rich in renewable energy sources, solar and wind, which nations can use to power their buildings sustainably.