The State of Carbon Dioxide Removal
Atmospheric carbon dioxide (CO2) levels have now reached global averages of at least 417 ppm, significantly higher than the 280 ppm seen prior to the industrial revolution. At these levels it is becoming important to not only discuss the reduction of CO2 emissions but what may be done to remove existing CO2 from the atmosphere.
The State of Carbon Dioxide Removal is a report published earlier this year by a group of experts in carbon dioxide removal (CDR) technologies and techniques, lead by Oxford’s Smith School of Enterprise and the Environment.
Currently CDR removes about 2 gigatons of CO2 per year, compared to over 34 gigatons of emissions. 99.9% of this CDR occurs through land management, which means planting trees and managing existing forests.
Although reforestation and forest management is by far the largest source of CDR, it is heavily dependent on available land, and the report states that novel techniques are needed — and need to be scaled quickly — in order to limit and reduce atmospheric CO2 levels and meet the temperature goals outlined in the 2015 Paris Agreement.
Some of these novel techniques include:
- BECCS: bioenergy with carbon capture and storage — the use of plant biomass for energy production paired with carbon capture technology. This can result in a process with less than zero emissions.
- Biochar: converting plant biomass to charcoal and then storing in soil
- DACCS: direct air carbon capture and storage — air is pulled in using large fans and then processed to remove and compress CO2, which can then be pumped into geologic formations deep underground.
- Other techniques: ocean fertilization, enhanced rock weathering
Operations using these techniques are all taking place on small scales but beginning to be build out.
CDR will be a vital part of the long term reduction of CO2 in the atmosphere, but it will still take decades to scale. This report aims to be the first in a series tracking global efforts towards that goal.
