The concrete that helps the climate

By Martha HenriquesFeatures correspondent@Martha_Rosamund

Concrete is the defining material of the Anthropocene and takes a terrible toll on the climate. Martha Henriques goes in search of the ways it could be better for the climate.

If you stroll between the towering apartment blocks of London's famous brutalist complexes, everywhere you look you will see the grey, pockmarked façade of concrete. Even the city's more modern skyscrapers conceal a backbone made of something less glamorous behind their shiny exteriors – more of the same old concrete.

From this urban concrete jungle to the vast swathes of the world's coastlines lined with concrete, concrete is arguably the material that best defines the Anthropocene. And we're using more of it almost every year. Soon there will be so much concrete in the world it will outweigh all living matter.

The problems that come with our extraordinary reliance on this material are many and varied. Blank stretches of concrete devoid of vegetation create biodiversity deserts. Concrete is also impervious to water, part of what makes it a great building material, but can lead to flooding in urban areas.

One of the biggest challenges for concrete is the sheer scale of its impact on the climate: about 8% of the world's greenhouse gas emissions. Cement, the component of concrete that acts as a binder to glue sand and stones together, is responsible for the bulk of concrete's carbon emissions.

But what if we could turn these vast grey swathes of building material into something that actually helps the climate? Concrete that doesn't emit carbon, and even absorbs it, is a crucial step along the way to sustainable construction.

Join me in the first episode of Future Planet's new video series, New Directions, where we explore what it takes to turn concrete from a major carbon source into a carbon sink.

* You can listen to more about whether our future greenhouse gas emissions are cast in concrete in this podcast from our colleagues on The Climate Question.

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