The State of Carbon Dioxide Removal: 3rd Edition
Carbon dioxide removal (CDR) will be necessary to limit climate change, accompanying rapid and deep emissions reductions. This report builds on the previous two editions to track CDR development. It highlights new insights, explores knowledge gaps and defines core concepts while also aiming to improve the reliability and accessibility of CDR data.
Climate change is mainly driven by emissions of carbon dioxide (CO2) to the atmosphere. These emissions come from human activities such as fossil fuel burning, land-use changes and industrial processes. Emissions of other greenhouse gases (GHGs), such as methane and nitrous oxide, are further exacerbating climate change. Whereas emission reduction seeks to limit the amount of CO2 newly released to the atmosphere, CDR involves taking previously emitted CO2 out of the atmosphere.
Meeting the Paris temperature goal – to limit global temperature rise to well below 2°C above pre-industrial levels and pursue efforts to limit the increase to 1.5°C – primarily requires rapid, deep and widespread reductions in emissions. CO2 emissions have an enduring effect on the climate, causing global temperature to rise and stay elevated for millennia. Halting the rise in global temperature will therefore require bringing emissions of CO2 all the way down to net zero. Reducing global temperature levels after a peak – for example, to return to 1.5°C after an overshoot period – would require net negative emissions, where global CO2 removals exceed global CO2 emissions.
The State of CDR 3rd Edition collates the latest information on the development of CDR. This first chapter sets out the role of CDR in climate change mitigation, defines CDR for the purposes of this report, outlines the characteristics of key CDR methods and presents an overview of the report and key improvements from previous editions.