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Ellina Webb looks at the increase in global emissions, how the construction industry affects it and what actions can help overcome it.

There are a number of problematic issues affecting the increase in global emissions over the past few years, one of them being the consumption of materials used to construct buildings.

In June 2019 The C40 Cities Climate Leadership Group announced that the impact of these problems are having a greater influence on global emissions than first thought, in fact consumption-based emissions from nearly 100 of the world’s big cities already represent 10% of global greenhouse gas emissions.

C40 is a group of 94 cities around the world, representing about a quarter of the global economy and a twelfth of the world's population.

According to new research by Arup and the University of Leeds, consumption-based emissions must be cut by at least 50% by 2030 in order to maintain the possibility of keeping the global temperature rise below 1.5C – as I have previously spoken about here.

Take a look at this infographic produced by Arup and the Green Construction Board’s Low Carbon Routemap for the Built Environment for a more visual understanding of the issue.

So how does the construction industry affect this?  How can we overcome it? And what will the benefits be?

Lowering the use of concrete or using alternative building materials is a must

Ellina Webb Ellina Webb Marketing Services Manager

26% by 2030

The report highlights how there is significant potential to cut consumption-based emissions in certain sectors, including construction which should aim to reduce this from buildings and infrastructure by 26% by 2030.

In order to cut these emissions this means a larger emphasis on procurements, life cycle assessments and design.

For example, increased use of electric machines in quarries will help to decarbonise supply chains, while a new independent body set up by the government could help to assess and accelerate the construction industry’s decarbonisation agenda – as suggested here.

The government could also look at setting up new regulations and incentives when it comes to building materials, as the C40 report states that this could “reduce steel and cement use by 35% and 56%, respectively”.

In Sweden, the construction and civil engineering sector has also adopted an “all-embracing roadmap to decarbonise construction”.

They hope this will stand as a rule of good practice for other nations too, helping us all work together in delivering a net zero carbon environment by 2050.

Use less and lower impact building materials

The C40 report states that “Switching to lower-impact materials such as sustainable timber (as a part replacement for concrete) is needed for 90% of homes and 70% of offices being built.”

It’s no surprise to learn that concrete production creates high levels of emissions, with the Guardian pointing out that if the global concrete industry were a country, it would be the world’s third biggest emitter!

This means that in order for the construction industry to decarbonise, lowering the use of concrete or using alterative building materials is a must.

In 2019 we have seen an increase in the number of ‘Ply-scrapers’ popping up in the planning process, as well as other timber based buildings.

There are also new ways to potentially reduce the emissions from concrete by substituting high emitting materials for sustainable ones. Furthermore, innovations such as the use of mycelium (the vegetative parts of fungus) are offering up new ways to build using carbon neutral materials.

When it comes to timber, this can be even more low impact if the timber used is reclaimed from a sustainably managed source, or within a certain distance.

This article on Inhabitat also discuses a huge number of alternative green building materials that are better than concrete in terms of a lower environmental impact.

These include straw bales which also naturally provide high-level insulation, a key requirement when reducing the load on heating and cooling (another issue when it comes to emissions). Others include GrassCrete which isn’t an alternative material but is a method of reducing concrete use in favour of grass in open areas, rammed earth, HempCrete, bamboo, recycled plastic and AshCrete.

My fellow Hub writer George Clarke also discusses these alternative building materials in his recent article here.


Use the full capacity and optimise efficiency

The C40 report states that “ensuring all buildings are being used to their full capacity could lead to a 20% reduction in the need for new buildings”. Improving this utilisation of buildings or even ensuring that older buildings are adapted for new uses could make a significant impact to this target.

With many buildings having a high output of carbon emissions due to ineffective energy use such as poor lighting and inefficient heating and cooling systems, modernisation of existing buildings also benefits overall low emissions targets – not purely consumption-based emissions.


The results? $11 billion in savings

If a city like London takes action on these points listed above, it would save more than $11 billion over the next 5 years. Beyond that it is estimated that the impact of the changes across all sectors would reduce the number of deaths per year, reduce the number of parking bays needed, allowing for more trees to be planted and generate more jobs.

To see the headline report and find out more please click here to download the report from the C40 website 

Ellina Webb is Marketing Services Manager at Mitsubishi Electric