Out of Eden: tackling emissions in the construction sector

‘The Garden of Eden is no more’, or so warned Sir David Attenborough in his speech to the World Economic Forum in Davos at the end of last month. In offering this stark warning, Attenborough gave voice to the growing public awareness that time is running out to solve the challenge of global warming. As he would go on to say: ‘We need to move beyond guilt or blame, and get on with the practical tasks at hand.’

It is without doubt that the construction sector has taken steps to reduce emissions, whether it be in the use of cross laminate timber, or rammed earth. The sector is moving in the right direction; but with the Government estimating that as much as 40% of the UK’s emissions come from the construction sector, predominately from the manufacture of construction products and materials, we still have a long way to go.

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Of course, making the construction sector ‘greener’ is difficult and certainly won’t happen overnight; but what if a possible solution was all around us – literally?

It may sound like science fiction, but carbon dioxide (CO₂) – so often maligned as the source of all of the world’s environmental problems – could soon be widely used as a raw material for construction and help reduce emissions.

We are already seeing such actions in other sectors. ClimeWorks, for instance, has pioneered a way to capture, purify and then use CO₂ as a renewable onsite resource in the food and agricultural industries, as well as for those that use CO₂ as a fuel or chemical raw material.

The construction sector could be next. Thanks to developments in catalytic science, it is now possible to create polyurethane using a process that replaces some of the oil-based raw materials with CO₂, thereby significantly utilising and preventing further emissions. Such plastics have wide ranging applications – everything from adhesives used to fix roof tiles in place through to window sealants, wooden floor coatings and rigid foam insulation. What’s more, such plastics function incredibly effectively: they provide good rigidity; increased abrasion resistance; improved chemical resistance; and, in the case of insulation, require less than half the amount of cork or mineral wools to provide the same degree of insulation, and have increased fire resistance.

It doesn’t stop here: it is even possible to create concrete, one of the biggest contributors to emissions, out of CO₂. For instance, CarbonCure technologies allow the CO₂ emitted during cement preparation to be transformed into nanosized mineral carbonates that are embedded within the concrete. Carbon8 Aggregate, meanwhile, has pioneered a process that uses CO₂ to transform thermal waste into artificial limestone.

We can tackle climate change; and although the clock is still ticking, the hands have not yet struck midnight. Innovations, such as converting CO₂ into a raw material, could help cut the construction sector’s emissions by vast amounts. In fact, using CO₂ to produce polyurethane would mean decreased carbon emissions – as much as 4 million cars’ worth each year. If, using the right technology, CO₂ could be adopted widely across the construction sector, the compound, so widely maligned as a threat to the planet, could yet help save it.

Dr Anthea Blackburn is a senior scientist - catalyst development at Econic Technologies