For many years, efforts to limit climate change have focused on curtailing anthropogenic emissions of greenhouse gases.  But it is increasingly clear that such curtailment will not, on its own, be able to prevent the damaging effects of global warming.  Therefore, more attention is now directed to mitigating climate change by enhancing the removal or sequestration of greenhouse gases from the atmosphere.  As a result, our climate change goals are now often specified in terms of when we plan to reach net zero emissions rather than on when we can just reach emission reduction targets. Phil Renforth is an expert on carbon sequestration.  He is especially interested in enhancing the weathering of rocks and has performed in-depth investigations of geochemical techniques of removing atmospheric carbon dioxide.  He is an Associate Professor in the School of Engineering and Physical Sciences at Herriot-Watt University. There are illustrations supporting this episode at geologybites.com.