St. Ives

What brings the team at Planetary to St. Ives? 

Message from Mike Kelland (CEO at Planetary):

While my family lives in Canada, we have deep family roots in Cornwall. My parents immigrated to Canada just before I was born and we have close family members who live there. I built sandcastles as a kid at Praa Sands, Perranporth and Gwithian, and my cousin taught me how to surf the waters of those same beaches. I’ve hiked the entirety of the South West Coastal Path around the Cornish coast. Cornwall has always felt like home.

St. Ives Bay is a region of natural beauty where the ocean plays a role in everyone’s life – whether it’s fishing, surfing, hiking, tourism or spending time on the beach. It’s no wonder that people are passionate about the environment in Cornwall.

Unfortunately, no matter how much work we may do to protect our coasts, our ocean is still under siege. 

Over the last 200 years, the world has put over a trillion tonnes of extra carbon dioxide (CO2) into the air. And this vast CO2 dumping is polluting our waters. The ocean and the atmosphere are tightly linked systems – about a third of that CO2 dumped into the atmosphere has ended up as carbonic acid in the ocean. The ocean has also absorbed 90% of the heat caused by climate change.  

We know that, on a global level, our waters are getting more acidic. When the CO2 seeps into the water, it turns into carbonic acid. We need to be clear on this point, ocean acidification because of CO2 pollution is already having a deep impact on marine ecosystems both here and around the world. In particular, shellfish and corals are becoming less abundant in many parts of the world and we are losing their biodiversity. 

We are interested to learn from the community whether you are directly witnessing any of these impacts in local fisheries, with coastal ecosystems and marine populations and so forth.  

Planetary’s core technology purifies antacid (magnesium hydroxide) from mine waste, producing battery metals and hydrogen along the way. The antacid is then used to neutralise CO2 in the ocean, and to reduce the amount of carbon in our atmosphere. This final step, what we call Marine Carbon Dioxide Removal (mCDR), is what we’re proposing to do in St. Ives. 

The Planetary mCDR process

Our proposed mCDR process can help to heal our damaged oceans, to take the pressure off of challenged local ecosystems, and to help with the climate threat. We have committed to approach the problem with care and respect. Based on the work done to date, we strongly believe that the benefits of this process – to both St. Ives and the world – heavily outweigh the risks. 

To make a difference with climate change, we know that we need to:

  1. Slow and stop carbon pollution. We absolutely need to reduce emissions to zero as quickly as possible. There is no alternative to that, and no matter how successful Planetary’s process is, it won’t make a difference unless we actively reduce worldwide emissions. 
  1. Address the ongoing effects of carbon pollution. When someone pollutes the environment, we don’t simply demand that they stop, we also require that they clean things up. Carbon is no different. We need to stop polluting our oceans and atmosphere with emissions AND we need to clean up the mess. 

The goal of the Planetary mCDR process is simple. We’ve been studying whether adding an antacid to the ocean is a safe and effective way of neutralising some of that acidic CO2. If it is, it has the potential to be a powerful way for us to clean up our oceans and our air. The research around the world – including our own – has been very promising. We have a high degree of confidence that small additions like the ones we have planned are safe. The science is still out on large scale work and no one that we know of is proposing large scale trials at this time. 

The antacid we use is called Magnesium Hydroxide – it neutralises CO2 in the ocean. For even more details, keep reading below.

We started discussions around St. Ives Bay with meetings with community and conservation groups in January of 2023. We progressed to open community meetings in late February. As a result of those meetings, there has been more interest than we can address in person. This webpage and all the information we’re sharing here is in response to that interest. We’ll be adding more to this page as time goes on. 

We’re committed to earning the trust of the community in the entire region around St. Ives Bay. My personal commitment is to listen carefully, approach this proposal with full transparency and to adjust our approach as needed based on feedback. 

We’re currently booking additional sessions with community groups in the region. If you have questions, concerns or feedback about our plans, we want to hear from you. Write us at If you simply want to stay up to date, you can sign up for a dedicated newsletter at the bottom of this page and/or keep checking back to this page. 

In simple terms, what is Planetary doing in St. Ives?

Suppose you’re a resident of Hayle or St. Ives or the surrounding area and one Saturday evening you rather overindulge at one of the many fine local establishments. Before retiring you might take a teaspoonful of milk of magnesia to combat a touch of heartburn.

This trial aims to validate that what works in the lab works here in Cornwall too – that we can reduce the ocean’s heartburn. We do it by adding a small amount of milk of magnesia (our antacid – Magnesium Hydroxide) into the  wastewater effluent from the treatment works. It’s not much – it’s less than half a teaspoon (2.5 ml) into a 15-litre/3-gallon bucket (put another way, it’s about 1 part Magnesium Hydroxide, 5000 parts wastewater effluent), but just like it works for you, it can help the ocean. Along with all of the wastewater from the Hayle/St. Ives region, this will be pumped through the discharge main and released into the sea to the northwest of the Godrevy lighthouse, about 1.5 miles off the coast.

The immediate effect on the marine environment will be immeasurably small. The amount in the effluent is small, and once it is diluted in the bay, the change in seawater chemistry is expected to be well below what can be measured. All of our testing in the lab and in small methods tests to date have proven this to be the case. 

The discharged water, with its tiny increase in alkalinity, will be carried up the coast by tidal drift, past Newquay and as far as Bideford, before dispersing north-west across the Bristol Channel toward the Pembrokeshire coast. Tidal eddies will carry a small amount of the discharge from Godrevy into St. Ives Bay—as is the case at present.

The particles of magnesium hydroxide that will be added to the wastewater effluent will be at least five times smaller than the finest particles of wheat flour or beach sand. We expect them to fully dissolve in a period of days to weeks, delivering what is effectively a slow-release antacid for the ocean.

If the trials prove successful, and the results of the study merit it, our sincere hope is that this process can run continuously in Cornwall. This would provide benefits to local ocean ecosystems, cleaning up some of the damage caused by climate change and would create new jobs as we establish Cornwall as a leader in ocean carbon removal. 

Why is Planetary doing this?

Planetary’s goals for this project are as follows:

  • Look for any discernible biological changes before, after and during the trial to ensure that the process is either neutral or beneficial to the local ecosystem
  • Validate CO2 removal and ocean de-acidification via a three-month controlled and monitored trial by dosing naturally sourced antacid (magnesium hydroxide) at a rate of 0.007% of the wastewater flow into St. Ives using in-pipe sensors and end-of-pipe buoys
  • Engage with local businesses especially in the marine sector and chart a path towards the potential to create new industry in the region 
  • Validate there are no unforeseen changes that occur throughout the process
  • Continue to engage in a community based process of learning together and earn the trust of the local community in order to bring the benefits of this solution to St. Ives.
  • Invite independent scientists and external verifiers to validate our results
  • Share results transparently and seek to improve any potential future iterations
  • Perform all work in alignment with our Code of Conduct
  • Keep developing ourselves and our work in alignment with our Vision, Mission and Values

Why is Planetary doing this in St. Ives?

Planetary has a presence and team members in Canada, US, and the UK and we have been actively working in the UK for the past two years. We were awarded funding from the UK government under the Direct Air Capture and other Greenhouse Gas Removal technologies competition during that time. This funding supported us to perform the necessary research and to build the partnerships and relationships in the UK to pursue this work. From this funded research, we were able to connect with and secure important partners on this journey with us. This led to working with Plymouth Marine Lab and proposing this project to the local regulator. 

St. Ives is not the only location where Planetary is actively seeking to apply and evaluate our process. We currently have a larger trial planned on the east coast of Canada and one planned for the west coast of Canada as well – these projects are in earlier stages of maturity though we hope to be in position to proceed over the next year.

The Cornish coast is very interesting for this kind of study because the water is shallow and turbulent and the currents keep that water in a shallow and turbulent area for a long time. In order for our process to remove CO2 from the air, the very slightly more alkaline water needs to remain close to the surface in what’s called the “mixing layer” of the ocean for a long period of time so that carbon can be absorbed. Working from Cornwall allows us to study the process at a small scale, with the benefit of these well-understood and ideal ocean conditions. 

The other two sites where we are working have very different conditions. On the east coast of Canada, we are working in an enclosed bay, which will provide more opportunities to measure things like accumulation of alkaline water over time.  On the west coast, we are working in an area where deep, CO2-rich (i.e., more acidic) water rises to the surface through a process called “upwelling”. In this region, we will examine how alkalinity can prevent CO2 from entering the atmosphere from the ocean rather than encouraging the ocean to pull it out of the air. 

Is it safe to add all this antacid? What’s the scientific perspective on this?

Magnesium hydroxide is already used to clean up acidic wastewater in treatment plants all over the world, and so it is very well studied and well regulated under permits. In addition, Planetary is committed to bringing a high standard of care to our work. Complying with existing permits for the use of our antacid is our starting point. We then add additional monitoring and biological surveys using a combination of sampling periods and continuously monitored sensors to ensure that our additions are not having unintended consequences. We do this sampling in partnership with academic institutions like Plymouth Marine Lab, local universities, and various other accredited laboratories in the region. 

Magnesium hydroxide, the antacid we use, is of low toxicity to aquatic organisms, just like it is to humans. It is safe to handle and consume when used properly. It is not classified as dangerous under the Classification, Labelling and Packaging (CLP) Regulation nor is it classified as persistent, bio-accumulative or toxic under the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) Regulation.

Alkaline bicarbonates (which are what we’re forming in the ocean as we add our magnesium hydroxide) are already among the most abundant ions in seawater. Marine ecosystems are well adapted to this alkalinity and it is essential as a substrate for marine photosynthesis and calcification (shell formation), as well as being critical for maintaining seawater pH and pH buffering capacity. The effect of adding additional alkaline bicarbonate or other forms of alkalinity on marine biota has generally been found to be neutral to positive (Comeau et al. 2012, Cripps et al. 2013, Waldbusser et al. 2015, Albright et al. 2016, Gore et al. 2019, Sanchez et al. 2023). For example, marine calcification was enhanced by such addition, helping to counter the negative effects of ocean acidification on Great Barrier Reef corals and shellfish caused by excess atmospheric CO2 (Albright et al. 2016). In Gran Canaria, alkalinity was added at very high levels and showed no long term effects on zooplankton. At smaller scales, calcium reactors are routinely used to beneficially generate calcium bicarbonate, a very similar product to ours, for saltwater aquaria. 

We also fund and support research at independent academic institutions. In addition to the published research above, Dalhousie University is studying the effects of the addition of our magnesium on plankton and oysters in the ocean. For plankton, the as-yet unpublished research is showing no effect on growth rates, reproduction or photosynthetic efficiency, even at dosing rates that are 10x higher than we are proposing. 

The team at Dalhousie was interviewed about their research recently on the NBC Today Show. 

A critical characteristic of magnesium hydroxide that greatly limits its potential environmental impact is the fact that it dissolves slowly.  That prevents rapid pH rises at the addition location, after which rapid dilution in the seawater will keep pH well within safe limits. In addition to these inherent mitigation factors, a controlled and monitored dosing system will ensure pH limits, and all environmental limits, are strictly followed. 

The standard way to determine if a product is safe in the ocean is something called a “96h LD-50” test. This test simply says, “add the sample organism to a bucket of water, then add the product until only half of them survive for 96 hours.”. The threshold for magnesium hydroxide depends on the species being tested. It ranges from 285 mg/L for water fleas to 1293 mg/L for trout. In essence, these numbers mean that you would need to add so much magnesium hydroxide that those animals would be “swimming” through a slurry of solid particles – that much of any solid would make it difficult for an aquatic creature to breathe, no matter what it was. In St. Ives, we’re staying well below that limit in the pipe, and even further below as it dilutes with seawater. 

There is a significant amount of work ongoing in this field around the world right now. The opportunity to clean up some of the carbon pollution in our oceans while at the same time cleaning our air is something that’s very attractive to a lot of people. This is leading to a flood of research and papers being published about ocean alkalinity enhancement and serious work on various approaches. 

Planetary’s approach is unique since we use a very pure product and we’re able to run each batch that we use through an analysis. This allows us to avoid the challenges of some other approaches like trace metals and high pH spikes.

The Planetary process of adding alkalinity to the ocean is the same process that nature uses to regulate the planet’s temperature. Over time, this process will restore ocean acidity to historical levels – it’s just that the natural process of rebalancing the atmosphere and the ocean works much too slowly. We need to de-acidify the ocean and reduce atmospheric carbon now if we want to avert the problems associated with ocean acidification and climate change. (see Kelly et al. 2005 if you are interested in academic studies). 

What exactly is happening in St. Ives in the coming months?

The project plan for the trial in St. Ives is below. This should be considered an outline as there are a number of things that could adjust this plan, including what we hear from the local community. 

Trial 1.0

June 2022Completion of in-lab and large scale “swimming pool” experimental program 
September 2022Initial systems and methods test in St. Ives
December 2022Provisional approval of this trial from the local regulator to be granted under the condition of:
– Environmental Impact Assessment Plan
– Detailed project lifecycle analysis (carbon footprint)
– Risk Assessment 
– Community Engagement
February 2023Release of the Monitoring, Reporting and Verification Framework 
February/March 2023Public information sessions and dialogue with the community at Hayle and in Truro. Engagement with community and conservation groups. 
March/April 2023Complete pre-trial biological surveys
Complete planning and submit full plan for permit approval for small scale initial trial 

Once biological surveys are complete, and we’ve addressed key concerns from the community, we intend to begin the trial. At the moment, this is tentatively scheduled for late spring of 2023. Once the trial completes, we’re committed to sharing the results of the science here on this page. 

Beyond St. Ives, what are Planetary’s goals?

Planetary Technologies’ vision is to protect and restore the ocean and climate for generations to come. Our team is made up of deep experts who have intentionally chosen this path to action around climate change. We believe that for-profit companies have a moral imperative to be a positive force for change in the world and that this is accomplished by meeting a high standard of social and environmental performance, transparency, and accountability.

We are actively pursuing B-Corp certification and have adopted values that we continually aim to develop in ourselves and each other as we learn and grow together.

Our journey doesn’t stop at St. Ives, and we are pursuing similar work in other regions around the world, with our next projects in Halifax and Vancouver.  In the year ahead and beyond this includes the ongoing research and development of technology to enable better monitoring and validation to ideally support incrementally larger scale work. 

How to Stay Involved and In Touch

We started our community outreach program through a series of individual and small group discussions. We then moved to in-person small group meetings at towns around the area (Hayle and Truro to start, others to come). 

Our next steps are to engage with additional interested individuals and groups on a one-on-one basis. If you are interested in staying involved or hearing more, please contact us at or sign up for the Planetary Newsletter below.  We’ll continue to update this page as well.

Additional Resources

The team at Planetary is happy to share resources to support learning more about anything that relates to our work. Below is a small curated list of topics and resources that we believe may be of interest.

How climate change is having an impact on oceans

United Nations: How is climate change impacting the world’s ocean 

Intergovernmental Panel on Climate Change: Special Report on the Ocean and Cryosphere in a Changing Climate

Science Direct: Responding to climate change around England’s coast – The scale of the transformational challenge 

Royal Meteorological Society: The North Atlantic Ocean and climate change in the UK and northern Europe

The London School of Economics and Political Science: How is climate change affecting coastal flooding in the UK?

National Oceanography Centre: Marine Climate Change Impacts

Related work and research published by the team at Planetary

Gov.UK – Direct Air Capture and other Greenhouse Gas Removal: Planetary: Phase 1 Report 

Scientific Views on the Marine Ecosystem Impacts of Ocean Alkalinity Enhancement (OAE)

European Geosciences Union (EGU) General Assembly: Atmospheric CO2 removal by alkalinity enhancement in the North Sea

Mitigation and Adaptation Strategies for Global Change: The potential environmental response to increasing ocean alkalinity for negative emissions

Nature: Reversal of ocean acidification enhances net coral reef calcification

Nature: Saturation-state sensitivity of marine bivalve larvae to ocean acidification

Science Direct – Marine Pollution Bulletin: Biological impacts of enhanced alkalinity in Carcinus maenas

Royal Society – Biological Sciences: Coral reef calcifiers buffer their response to ocean acidification using both bicarbonate and carbonate

National Academies of Sciences, Engineering, and Medicine (2021). A research strategy

for ocean-based carbon dioxide removal and sequestration

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