Carbon Dioxide Removal
May 22-26, 2017
There is a wide gap between the aspirational goals of the Paris agreement (i.e., stabilization at less than 2°C) and the Nationally Determined Contributions (NDCs) to reduce CO2 emissions. As a result, it is becoming more and more apparent that we will shoot right past the 2°C target. As a result, there has been a significant increase in interest in CO2 removal (CDR) technologies. These technologies have the capacity to remove CO2 from the atmosphere and, at least theoretically, correct in any overshoot of the 2°C goal. The CDR technologies most often cited are (from Smith, et al., “Biophysical and economic limits to negative CO2 emissions”, Nature Climate Change, 6, January (2016).): • BECCS: Bioenergy with carbon capture and storage • DAC: Direct air capture of CO2 from ambient air by engineered chemical reactions • EW: Enhanced weathering of minerals, where natural weathering to remove CO2 from the atmosphere is accelerated and the products stored in soils, or buried in land or deep ocean • AR: Afforestation and reforestation to fix atmospheric carbon in biomass and soils • Ocean: Manipulation of carbon uptake by the ocean, either biologically (that is, by fertilizing nutrient-limited areas) or chemically (that is, by enhancing alkalinity) • Agriculture: Altered agricultural practices, such as increased carbon storage in soils • Biochar: Converting biomass to recalcitrant biochar, for use as a soil amendment. This talk will focus on the technologies from the above list related to carbon dioxide capture and storage (CCS). Two of the above technologies have CCS at their core, BECCS and DACS. EW includes carbonate mineralization, which is part of the CCS portfolio. Finally, there is some overlap with Ocean, since not so long ago storing captured CO2 in the ocean was under serious consideration. This talk will present a high-level technological assessment for these CCS related CDR options. The talk will also discuss the following key questions: • What are the economics of these technologies? • Can these technologies scale to gigaton levels? • Will these technologies present public acceptance issues?
Howard Herzog, "Carbon Dioxide Removal" in "CO2 Summit III: Pathways to Carbon Capture, Utilization, and Storage Deployment", Jen Wilcox (Colorado School of Mines, USA) Holly Krutka (Tri-State Generation and Transmission Association, USA) Simona Liguori (Colorado School of Mines, USA) Niall Mac Dowell (Imperial College, United Kingdom) Eds, ECI Symposium Series, (2017). https://dc.engconfintl.org/co2_summit3/48