Ocean Alkalinity Enhancement – A preliminary research agenda and maturation roadmap

CarbonActionNow! is pleased to announce the publication of this white paper, which can be downloaded here.


Global anthropogenic CO2 emissions have continued to increase since the Paris Climate Agreement was adopted in 2015, lifting atmospheric CO2 concentration from a peak monthly average of 404 ppm in 2015 to 415 ppm in 2019. The continuing delay in leaving peak CO2 emissions in our wake increases the likely scale at which CO2 will have to be removed from the atmosphere, during this century and beyond, if the Paris goal of limiting warming to well below 2°C is to be achieved. Estimates of the scale of carbon dioxide removal (CDR) needed to meet the 2°C goal range from 100 to 1000 GtCO2 by 2100, with a removal rate potentially reaching 10 GtCO2/yr by 2050 and 20 GtCO2/y by 2100.

However, many of the technologies that will need to be deployed to reach this scale have made little progress beyond the laboratory bench. A 2019 US National Academies of Sciences, Engineering, and Medicine (NASEM) study sought to accelerate the maturation of these technologies by developing a research agenda addressing current knowledge gaps, as well as opportunities for cost reduction and other issues that could constrain deployment. Ocean-based approaches were beyond the scope of the NASEM study, posing the risk of delayed maturation in this area, and a reduction in the total CDR achievable by 2100.

This working paper follows the NASEM approach in establishing a preliminary research agenda for ocean alkalinity enhancement (OAE), and also outlines a technology maturation roadmap towards large-scale deployment. The two-fold aim of this work is, firstly, to focus R&D attention on knowledge gaps that must be closed to enable informed decisions on OAE demonstration and later deployment activity and, secondly, to identify the potential longer term, primarily non-technical barriers to impact scale OAE deployment that need to be addressed, in parallel with other early stage work, in order to provide the foundation for such deployment, if this is eventually undertaken.

UK Open Consultation on Carbon Emissions Tax

This UK Government open consultation sought comments on how, if introduced, the Carbon Emissions Tax would operate, and also on proposals for further development of the tax, including the possible inclusion of negative emissions.

CarbonActionNow! prepared a submission focusing on the negative emissions questions, which can be downloaded here.


Large scale deployment of carbon dioxide removal (CDR) methods to deliver negative emissions will be essential for the UK to meet its NDC commitment towards the Paris climate goals and will require the support of a wide ranging policy framework. However, linking negative emissions too quickly to policy mechanisms aimed at reducing emissions (e.g. the Carbon Emissions Tax or a UK ETS) would be problematic.

Targets, reporting, and markets for emissions reduction and for negative emissions should initially be kept strictly separate, and (dis)incentives should be designed to ensure the needed progress in both these areas.

Incentives to encourage the research, development and demonstration of promising CDR methods need to;

  • Keep options open
  • Ensure dependable support for demonstration projects
  • Demonstrate a clear pathway to commercialisation, and
  • Explicitly foster learning.

A number of complementary actions and policies are recommended to support of the UK’s overall net-zero objective, including;

  • Launching a Citizens’ Assembly to consider CDR deployment in the UK
  • Commissioning a strategic environmental assessment of CDR deployment in the UK
  • Commissioning a study on the integration of direct air capture into the UK energy system
  • Avoiding the labelling of specific sectors as “hard to abate”
  • Acknowledging and addressing the UK’s carbon debt
  • Increasing durable carbon utilisation, and
  • Introducing incentives for the use of low carbon fuels.