In this episode, Nick Breeze speaks with Dr. Claudia Wieners, climate scientist at the University of Utrecht, to explore one of the most urgent and controversial questions in climate science: could Stratospheric Aerosol Injection (SAI) be used to prevent the collapse of the Atlantic Meridional Overturning Circulation (AMOC)?
Dr. Wieners explains how AMOC is driven to collapse by two key forces — ocean warming and freshwater influx from increased rainfall and Greenland melt — and why SAI could theoretically counter both. She breaks down the role of the subpolar gyre and deep convection zones in sustaining AMOC, and why the timing of any SAI deployment is absolutely critical: wait too long, and you don't just fail to save AMOC — you could trigger a dangerous "double cooling" effect around the North Atlantic.
The conversation also tackles the complex trade-offs that make SAI so politically charged: its potential impact on the Amazon rainforest, the risk of it being used as a pretext to slow down emissions reductions, and why many EU policymakers refuse to engage with the topic at all — even though, as Dr. Wieners argues, that refusal itself carries serious risks.
Dr. Wieners outlines what a credible research programme would look like: better climate modelling, small-scale stratospheric measurements, and international monitoring infrastructure — and she issues a sobering warning that every year of delay increases the chance we've already crossed a critical threshold for AMOC without knowing it.
🔔 Subscribe for more in-depth conversations on climate tipping points, geoengineering, and the science shaping our future.
New Zealand