Take action on climate change at http://countdown.ted.com/. Concrete is the second most-used substance on Earth (behind water), and it's responsible for eight percent of the world's carbon footprint. Cement researcher Karen Scrivener shares the research behind a pioneering new kind of cement known as LC3, which could slash carbon emissions from this crucial building material by 40 percent, if adopted at scale. This talk was part of the Countdown Global Launch on 10.10.2020. (Watch the full event here: https://www.youtube.com/watch?v=5dVcn8NjbwY.) Countdown is TED's global initiative to accelerate solutions to the climate crisis. The goal: to build a better future by cutting greenhouse gas emissions in half by 2030, in the race to a zero-carbon world. Get involved at https://countdown.ted.com/sign-up Become a TED Member: http://ted.com/membership Follow Countdown on Twitter: http://twitter.com/tedcountdown Follow Countdown on Instagram: http://instagram.com/tedcountdown Subscribe to our channel: null TED's videos may be used for non-commercial purposes under a Creative Commons License, Attribution–Non Commercial–No Derivatives (or the CC BY – NC – ND 4.0 International) and in accordance with our TED Talks Usage Policy (https://www.ted.com/about/our-organization/our-policies-terms/ted-talks-usage-policy). For more information on using TED for commercial purposes (e.g. employee learning, in a film or online course), please submit a Media Request at https://media-requests.ted.com/