Why we need a code of conduct for ocean-based carbon dioxide removal

It is becoming clearer with every passing day and with every new high-level report that we need to take immediate and increasingly drastic action to blunt our current climate crisis.

Cutting our reliance on fossil fuels is no longer enough. We need to find ways to safely remove and store carbon—a strategy known as carbon dioxide removal (CDR)—to achieve “net negative emissions”. But it is imperative that we don’t make a bad situation worse.

Every year, humans pump more than 40 billion tons of carbon dioxide into the atmosphere. Heat from this greenhouse gas is disrupting planetary systems and reshaping life on Earth.

The Intergovernmental Panel on Climate Change (IPCC) has warned of catastrophic and irreversible climate impacts with warming of 1.5°C above pre-industrial global average temperatures – and we are currently at 1.2°C. It also calculated the amount of time left to us under current emissions trajectories before we reach that limit – about 10 years.

To be clear, there is no one strategy that will buy us the time we need to truly decarbonize the global economy and start drawing down carbon dioxide already in the atmosphere. But we would be smart to look to the ocean in our time of need.

We live on an ocean planet, after all, and it is the greatest reservoir of water, the largest habitat, and a sink for nearly one third of anthropogenic carbon emissions and more than 90% of the resulting heat.

The ocean contains 50 times more carbon than the atmosphere and 20 times more than all the carbon stored in land plants and soils. If we are going to manage atmospheric carbon dioxide levels to our advantage, we will need to leverage the ocean’s existing ability to govern the global carbon cycle.

In fact, several land- and ocean-based carbon dioxide removal strategies have already been proposed that may be able to achieve the annual billion-ton scale needed to make a dent in existing emissions.

Common challenges and R&D agendas for ocean CDR have been detailed in a recent report by the US National Academies of Science, Engineering, and Medicine. Moving forward with any of these approaches at scale hinges on answering two critical questions:

1. Will we be able to durably remove carbon dioxide from the atmosphere – that is, keep it out of the atmosphere at time scales that will make a difference in our efforts to forestall climate disruption?

2. Will there be ecological consequences that we can accept or that we should avoid at all costs?

Finally, the consequences of ocean CDR need to be weighed against changes in the ocean already upon us, including (and as a result of) rising temperatures, increasing acidity, disrupted food webs, Arctic melting, alterations in ocean nutrient cycles and many more.

These are not questions we can put off answering, as they speak to whether society will be able to achieve our overarching goals while, at the same time, not doing greater and perhaps even irreparable harm to the planet in the process.

Answering these questions while evaluating the effectiveness of the various carbon dioxide removal strategies will require field experiments specifically designed to explore outcomes that cannot be tested with laboratory or model experiments.

Field studies are needed in particular to address uncertainties about potential ecological consequences, the efficiencies and permanence of enhanced carbon sequestration, and whether the strategy being tested is a practical approach to provide quantifiable climatic benefits.

But as scientists and members of society, we have a responsibility to move forward with care at the same time that we treat this issue with the urgency it deserves.

As a result, a group of us – of which this team is just a part – who are principally focused on iron fertilization have drafted a code of conduct to govern our work in the arena and we are proposing it as a foundation to help guide research into any ocean- or land-based CDR strategy.

These guidelines come at the same time others have made clear the pressing need for an ethical framework and they have their origin in a meeting at Asilomar in 2010. This brought together an international and wide-ranging group of experts from academia, government agencies, nongovernmental organizations and the business community, who considered principles for responsible conduct of climate engineering research.

The key points are:

1. Prioritize collective benefit: The collective benefit to humankind and the environment must be the primary purpose of research conducted to develop and evaluate the potential for climate intervention technologies to moderate or reverse human-induced climate change.

2. Establish responsibility: Governments and public agencies must clarify responsibilities for and, when necessary, create new mechanisms to govern and oversee large-scale climate intervention research activities that have the potential or intent to significantly modify the environment or affect society. These mechanisms should build upon and expand existing structures and norms for governing scientific research and, in the event of damaging outcomes, establish who would bear the cost.

3. Commit to open and cooperative research: Research should be conducted openly and cooperatively, preferably within a framework that has broad international support. Research activities with the potential to affect the environment in significant ways should be subject to risk assessment, considering the risks and their distribution associated with both the activity itself and the ongoing limits to understanding if the experiment is not conducted.

4. Perform evaluation and assessment: Iterative, independent technical assessments of research progress on climate intervention approaches will be required to meet societal goals. Assessing any intended and unintended consequences, impacts, and risks will be critical to providing policymakers and the public with the information needed to evaluate the potential for climate interventions to be implemented as a complement to greenhouse gas reductions, mitigation, and adaptation strategies.

5. Engage the public: Public participation and consultation in research planning and assessments, and in the development of decision-making mechanisms and processes, must be enabled to ensure consideration of the international and intergenerational implications of climate intervention strategies and activities.

We propose these or similar guiding principles be adopted as early as possible during development and assessment of all forms of ocean- or land-based CDR strategies. We also urge others to join in adopting these principles into a common carbon dioxide removal code so that the scientific community will move forward responsibly.

We strongly support the science leadership at American Geophysical Union (AGU), who are embarking on a path to develop an ethical framework around climate intervention that is in the best interests of the planet and society, as we advance research into different carbon dioxide removal approaches.

The stakes could not be higher, for science and society. We have to act now in order to ensure that we have the science we need for the future we want.