What is marine CDR (mCDR) technologies?

Carbon dioxide removal (CDR), specifically referring to marine CDR (mCDR) technologies, are those that aim to capture and store excess carbon dioxide (CO2) from the atmosphere in the ocean.

These technologies are being explored as a potential way to mitigate climate change by directly addressing the root cause – rising atmospheric CO2 levels.

 mCDR technologies:

• Goal: Reduce atmospheric CO2 by capturing and storing it in the ocean for long periods.
• Importance: Since the ocean already absorbs a significant portion of atmospheric CO2, mCDR leverages this natural process for additional CO2 removal.

Types of mCDR Technologies (various stages of development):

• Ocean Alkalinization: Adding substances like limestone or crushed rocks to seawater to increase its capacity to store CO2.
• Nutrient Enrichment: Adding iron or other nutrients to specific areas to stimulate the growth and activity of phytoplankton, which absorb CO2 during photosynthesis and sink to the ocean floor when they die, storing the carbon.
• Enhanced Weathering: Grinding silicate rocks and spreading them on land or in the ocean to accelerate their natural CO2 capture process through weathering.
• Ocean Afforestation: Growing large kelp forests or other marine plants that absorb CO2 and store carbon when they die and settle on the seabed.

Potential Benefits:

• Direct CO2 Removal: mCDR technologies offer the potential to directly remove CO2 from the atmosphere, complementing efforts to reduce emissions at the source.
• Synergy with Natural Processes: Many mCDR methods work by enhancing natural ocean CO2 absorption processes, potentially leading to a more sustainable approach.

Challenges and Considerations:

• Limited Scalability: Most mCDR technologies are still in the early stages of development, and their effectiveness at large scales needs to be proven.
• Environmental Impacts: Potential unintended consequences on marine ecosystems need careful study before widespread deployment.
• Monitoring and Verification: Efficient methods for monitoring and verifying the amount of CO2 removed from the atmosphere and stored in the ocean are crucial.
• Cost and Energy Consumption: Developing and implementing these technologies might require significant resources and energy.

Overall, mCDR technologies represent a promising avenue for addressing climate change. However, further research, development, and careful evaluation are needed before large-scale deployment can be considered.