Greenhouse gas removal (GGR) technologies are broadly recognised as being indispensable to a 1.5 °C target, and even more so with a growing number of countries committing to net-zero emissions by 2050. GGR approaches are designed to enable the removal of CO2, or other greenhouse gases, from the atmosphere. GGR development covers a broad range of disciplines, from agricultural practices (e.g., biochar and soil carbon sequestration) to engineering processes (e.g., BECCS, direct air capture). The deployment of GGR at scale will have environmental, economic, and social impacts, as well as affecting competition for land, water and energy usage. There are potential impacts to biodiversity, physical climate feedbacks, e.g., albedo modification, or the release of other greenhouse gases. Therefore, understanding the fundamental science behind GGR technologies will be essential. Also critical will be the development of policies to support GGR deployment, ensuring there is synergy with other decarbonisation efforts. In this context, recognising the specific climate repair value (CRV) that GGR pathways provide and carefully distinguishing CRV from other environmental co-benefits will be key.
This book sets out to provide a resource that is of use to those working in as many of these areas as possible. Our aspiration is that graduate students, researchers, and industry professionals who are joining our community will find this book a useful resource to help them in their work.
Mai Bui and Niall Mac Dowell