CO₂-removal News

Re-carbonizing the sea: Scientists to start testing a big ocean carbon idea

by Jeremy Hance, on, 25 January 2023

„Ocean alkalinity enhancement (OAE) involves releasing certain minerals into the ocean, sparking a chemical reaction that enables the seawater to trap more CO₂ from the air and mitigating, albeit temporarily, ocean acidification. Some scientists believe OAE could be a vital tool for drawing down and securely storing some of the excess CO₂ humanity has added to the atmosphere that is now fueling climate change. Yet many questions about OAE remain, including most prominently how it would impact marine life and ecosystems. Several programs are aiming to spark the research needed to answer these questions, including field tests in the ocean.“


Nature-Gruber et al. (2023): Trends and variability in the ocean carbon sink

Nicolas Gruber, Dorothee C. E. Bakker, Tim DeVries, Luke Gregor, Judith Hauck, Peter Landschützer, Galen A. McKinley, Jens Daniel Müller IN: Nat Rev Earth Environ (2023).

In this Review, the authors discuss trends and variations in the ocean carbon sink. The sink stagnated during the 1990s with rates hovering around –2 Pg C year–1, but strengthened again after approximately 2000, taking up around –3 Pg C year–1 for 2010–2019. The most conspicuous changes in uptake occurred in the high latitudes, especially the Southern Ocean.


Webinar on ocean-based CDR with CDRmare

Tuesday, February 7, 2023, 4 p.m. to 5 p.m.; hosted by Swiss Carbon Removal Platform

In this CDR Swiss webinar, Prof. Dr. Gregor Rehder and Prof. Dr. Achim Kopf from the German research mission „CDRmare“ will present marine Carbon Dioxide Removal (CDR) methods, including carbon storage in the oceanic crust (basalt formations) and in geological formations of the German North Sea (sand stone formations).


Four job openings (2 PhDs, 2 Postdocs) at GEOMAR in relation to ocean alkalinity enhancement

Application deadline: February 6th, 2023

GEOMAR is hiring for 1 postdoc and 2 PhD positions in pelagic ecology and/or biogeochemistry in the research unit Biological Oceanography and 1 postdoc position in modelling physical-biogeochemical interactions of ocean alkalinity enhancement in the research unit Marine Biogeochemical Modelling:

All positions are part of the consortium style international research project “OCEAN ALK-ALIGN: Aligning Ocean alkalinity for sustainable, safe and verifiable long-term CO2 removal” that will investigate the potential of ocean alkalinity enhancement (OAE) as a means of CDR. OCEAN ALK-ALIGN aims to close existing knowledge gaps by investigating three aspects essential for possible OAE implementation: (1) the efficiency and permanence of CO2 removal; (2) environmental safety; (3) monitoring and verification.

Nature – Carbon capture nets 2 billion tonnes of CO2 each year — but it’s not enough

Miryam Naddaf, on, 23 January 2023

„As well as cutting emissions, governments need to ramp up investment in carbon dioxide removal technologies to hit climate goals, researchers warn. (…) The report, called The State of Carbon Dioxide Removal, provides the first global estimates of the total amount of carbon that is being sucked out of the air each year, and predicts how much this will have to increase under various emissions scenarios.“


A Solution to Excess CO2? New Study Proposes Fertilizing the Ocean

by Beth Mundy on, January 20, 2023

„An international team of researchers led by Michael Hochella of the Pacific Northwest National Laboratory suggests that utilizing tiny organisms could be a solution to addressing the pressing need to remove excess carbon dioxide from the Earth’s environment. The team conducted an analysis, published in the journal Nature Nanotechnology, on the possibility of seeding the oceans with iron-rich engineered fertilizer particles near ocean plankton, crucial microscopic plants in the ocean ecosystem, to boost the growth and carbon dioxide uptake of phytoplankton.“


Scientific researcher (m/f/x) modeling Earth system feedbacks

Deadline for application: Feb 12, 2023

The chair for Physical Geography and Land Use Systems (Prof. Julia Pongratz) at LMU’s Department of Geography (University of Munich, Germany) is looking for a scientific researcher.

The scientific researcher will be part of the Horizon Europe project “RESCUE”, which comprises a large model intercomparison project to quantify the Earth system response to pathways achieving climate neutrality by Carbon Dioxide Removal (CDR) deployment. A special focus lies on Earth system feedbacks and aspects of reversibility and environmental risks under scenarios of temperature overshoot. In RESCUE, the scientific researcher at LMU will

  • contribute to the design of CDR scenarios as a collaboration of Earth system and socioeconomic modelers,
  • set up, run and analyze model simulations of the ICON/MPI Earth System Model,
  • further develop methods of “detection and attribution” in order to improve recommendations on the setup of observational systems for early detection of CDR signals and side-effects,
  • take a leading role in the development of scientific publications.


Moinet et al. (2023): Carbon for soils, not soils for carbon

Gabriel Y. K. Moinet, Renske Hijbeek, Detlef P. van Vuuren, Ken E. Giller IN: Global Change Biology,

The authors critically re-examine the benefits of global SOC (soil organic carbon) sequestration strategies on both climate change mitigation and food production. While estimated contributions of SOC sequestration to climate change vary, almost none take SOC saturation into account. Here, the authors show that including saturation in estimations decreases any potential contribution of SOC sequestration to climate change mitigation by 53%–81% towards 2100. In addition, reviewing more than 21 meta-analyses, they found that observed yield effects of increasing SOC are inconsistent, ranging from negative to neutral to positive. Tha authors find that the promise of a win-win outcome is confirmed only when specific land management practices are applied under specific conditions.