The potential and risks of atmospheric CO2 removal in net zero pathways: Science and policy reflections
Models that combine carbon, climate and economic systems have indicated, since the time of the Paris Climate Agreement, that to limit the magnitude of climate change requires not only substantial reduction in emissions of CO2 but also active removal of CO2 from the atmosphere. Such CO2 removal (CDR) is required to net off continued emissions from sectors that are challenging to decarbonise and to reach ‘net zero’.
It remains unclear how to achieve CDR at the required Gtonne level in ways that are economically and environmentally sustainable, but a large number of companies, small and large, are developing possible routes to commercial CDR. This talk will summarise the growing field of CDR science, business and policy, and will argue for the critical importance of environmental science as CDR solutions are developed.
Options for CDR range from engineered solutions which chemically scrub CO2 from the atmosphere to solutions involving accelerating naturally occurring processes (biological and inorganic). I will describe the chemical and environmental challenges of some of these approaches and their scale up, focusing on two approaches in particular: enhancing weathering of silicate minerals in soils, and increasing the alkalinity of seawater.
