Oxford Type 5

Long-lived removal

This is a highly diverse category of projects that includes cutting-edge engineered solutions that hold significant promise but are not yet available at scale. Examples include direct air capture technology and storage of carbon through enhanced rock weathering.


The best science suggests that any pathway to avoiding the worst effects of climate change will require between 100 and 1,000 gigatons of carbon removal over the course of the 21st century. This category represents the best opportunity to deliver on that gigaton scale permanent removal by leveraging new technology.


  • Limited Supply:
    These technologies have not reached operational scale, meaning that they are limited in availability and immediate impact.
  • Technology risk:
    Technologies in this category are largely experimental, so there are not yet fully-developed certifications and processes to measure and verify the amount of carbon removed.
  • Price:
    Because the technologies are subscale and experimental, tons of CO2e from this category can cost hundreds or even thousands of dollars.