CONCRETE RESULTS

Cement, a literal building block of society, is a huge greenhouse gas emitter. Swiss building materials giant Holcim is starting to change that.

- Peter Vanham

IN ITS PEACEFULNESS AND CIVILITY, it may have been the most Swiss protest ever. At a classical music concert in the picturesque city of Lucerne in September, two climate activists glued themselves to the stage. The orchestra's performance wheezed to a halt, much to the audience's chagrin.

After a brief negotiation, conductor Vladimir Jurowski announced a truce: The young protesters would be allowed to make their case, everyone in the audience would listen, and the concert would continue. What the protesters demanded wasn't an end to oil exploration, or that everyone stop flying or driving, or that the old guard step down for having let the planet burn. Instead, they called for something else entirely: that all Swiss homes be renovated by 2030 so they could stay cool in summer, and warm in winter-but while using much less energy.

The Lucerne saga was over after four minutes. But the Renovate Switzerland movement has engineered dozens of similar protests in the country since 2022, some of them much more disruptive-including a blocking of the main Lake Geneva bridge by protesters similarly glued to the surface, and protesters "slow-walking" traffic by marching down the middle of busy city streets. What the actions have in common is an urgent plea for a less carbon-dioxide-heavy "built environment." 

It's a demand that makes sense. For all the attention given to cars, trucks, and airplanes, it turns out that houses and buildings actually make up the world's single largest source of CO₂ emissions, at a staggering 39%. The production of cement alone- omnipresent in our buildings, bridges, and sidewalks - is responsible for almost a quarter of those emissions. That's due to the chemical processes and intense heat required to manufacture it, most of which typically involve fossil fuels.