Cheaper, Cleaner, Deeper: Can the Ocean Deliver Durable Carbon Removal?

Send me a message In this episode of Climate Confident, I spoke with Ori Shaashua, Co-founder and CCO of Gigablue, a marine carbon dioxide removal (mCDR) company taking a radically scalable approach to the carbon challenge. Gigablue’s MCFS (Marine Carbon Fixation and Sequestration) method taps into the ocean’s natural carbon cycle by cultivating phytoplankton in floating substrates and using gravity, not high-energy processes, to sink captured CO₂ to deep-sea sediment for thousands of years. It’s a low-energy, high-durability method that’s already secured the largest ocean carbon removal offtake to date. We unpack why mCDR matters, how it compares to nature-based and tech-heavy CDR approaches, and what makes ocean deserts, like those off the coast of New Zealand, ideal sites for safe and measurable sequestration. Ori also outlines their scale-up pathway: from kiloton removals today to multi-megaton capacity by 2029, and potentially gigaton-level by 2035. We dive into the mechanics of traceability, the real costs of permanence, and why MRV (Measurement, Reporting, and Verification) is the make-or-break for CDR credibility. Ori also pulls no punches on what’s holding back progress: delayed regulation, weak compliance markets, and over-reliance on short-term carbon offsets. If your company is thinking seriously about durable net zero strategies, or wondering how ocean-based carbon removal fits into the climate tech landscape, this episode delivers real insight. 🎧 Listen now to learn how Gigablue is pushing marine CDR from pilot to planetary scale. Support the show Podcast supporters I"d like to sincerely thank this podcast"s amazing supporters: Jerry Sweeney Andreas Werner Stephen Carroll Roger Arnold And remember you too can Support the Podcast - it is really easy and hugely important as it will enable me to continue to create more excellent Climate Confident episodes like this one. Contact If you have any comments/suggestions or questions for the podcast - get in touch via direct message on Twitter/LinkedIn. If you liked this show, please don"t forget to rate and/or review it. It makes a big difference to help new people discover the show. Credits Music credits - Intro by Joseph McDade, and Outro music for this podcast was composed, played, and produced by my daughter Luna Juniper