Sequestration

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At some stage before 2050, it is likely there will need to be a new industry for the sequestration of CO2e from anthropogenic sources or directly the atmosphere. It is essential that this should not contribute to ocean acidification - it would be a bonus if it tended to mitigate it. Please list all the potential strategies, from which we can trim down to a shortlist.



Certainly! The sequestration of CO2 and other greenhouse gases, especially from anthropogenic sources, is becoming increasingly vital as we look to combat climate change. Here are potential strategies for sequestration that don't contribute to ocean acidification and might even help mitigate it:

• Direct Air Capture (DAC):
  • Involves machines that pull CO2 directly from ambient air and then store it or use it.
  • It's purely a mechanical/chemical process and has no impact on the oceans.
  • When combined with sequestration, it provides a net reduction in atmospheric CO2.
• Enhanced Weathering:
  • Minerals like olivine can react with CO2 to form carbonates.
  • This can be done on land, grinding up the minerals and spreading them on fields.
  • If done appropriately, it can prevent the leaching of acids into oceans.
• Afforestation and Reforestation:
  • Planting trees and restoring forests can absorb significant amounts of CO2 from the atmosphere.
  • Additionally, sustainable forest management can be a carbon sink.
• Bioenergy with Carbon Capture and Storage (BECCS):
  • Involves growing biomass, burning it to produce energy, and then capturing and storing the CO2 produced.
  • The net effect can be a removal of CO2 from the atmosphere if sustainable practices are used.
• Soil Carbon Sequestration:
  • Agricultural practices, like agroforestry, conservation tillage, and cover cropping, can increase the amount of carbon stored in soils.
  • Healthy soils store more carbon and can also prevent soil erosion and runoff that might contribute to ocean acidification.
• Enhanced Coal Bed Methane Recovery:
  • Involves pumping CO2 into unmineable coal seams, displacing methane (which can be used as energy), and sequestering CO2 in the process.
• Carbon Mineralization:
  • Involves reacting CO2 with calcium or magnesium to form carbonates.
  • These stable carbonates can be stored underground or used in construction.
• Carbon-negative Concrete:
  • Some new concrete formulations absorb CO2 as they cure.
  • This could become a sink for CO2 if widely adopted.
• Blue Carbon:
  • Coastal ecosystems like mangroves, salt marshes, and seagrass meadows capture and store significant amounts of carbon.
  • Protecting and restoring these ecosystems can serve as carbon sinks and provide resilience against rising sea levels.
• Ocean Alkalinity Enhancement:
  • Directly addresses ocean acidification by adding alkaline substances to the ocean, increasing its capacity to absorb CO2.
  • Care has to be taken to understand potential side effects.
• Seaweed Farming:
  • Some macroalgae species grow rapidly and can sequester significant CO2.
  • Harvesting and sinking the seaweed to deep oceanic depths can sequester the carbon for centuries to millennia.
• Carbon Capture and Storage (CCS):
  • Capturing CO2 at the point of emission (like power plants) and then storing it underground in geological formations.

When considering these strategies, it's essential to perform a comprehensive assessment, looking at scalability, economic viability, potential side effects, and overall impact on both atmospheric CO2 and oceanic health.


Let's begin with scalability. A reasonable order of magnitude for the required annual sequestration is 10 billion tonnes of carbon. That assumes 70% of nations achieve Net Zero at 2050 and that 70% of their energy use is renewable. If you feel my order of magnitude is incorrect we can delve for a better figure.



Your estimate of 10 billion tonnes (10 Gt) of carbon (equivalent to around 36.7 Gt CO2) as an annual sequestration target by 2050 under the assumptions you provided is a fair starting point, given the current and projected anthropogenic emissions. It's also consistent with many high-emission scenarios that scientists and policymakers use for planning. Still, it's worth noting that exact numbers can vary based on various factors like economic growth, adoption rates of green technologies, unforeseen technological breakthroughs, and more.

Let's evaluate the scalability of the methods listed:

• Direct Air Capture (DAC):
  • Current facilities can capture thousands of tonnes per year, but scaling to billions would require significant infrastructure and energy. It's feasible with enough investment and the right energy sources, but it's a significant challenge.
• Enhanced Weathering:
  • Large-scale mining and distribution of minerals would be required. While technically possible, the environmental impact and energy required for such operations would be significant.
• Afforestation and Reforestation:
  • One mature tree can absorb about 22 kg of CO2 per year. Thus, billions of trees would be needed, requiring vast land areas. It's one of the more feasible options, but land competition with agriculture and urbanization can be a challenge.
• BECCS:
  • Current BECCS projects operate on the scale of millions of tonnes annually. Scaling to billions is challenging due to land and water needs for biomass cultivation and potential competition with food production.
• Soil Carbon Sequestration:
  • Potential to sequester billions of tonnes but requires global adoption of sustainable farming practices and land management.
• Enhanced Coal Bed Methane Recovery:
  • Limited scalability because it's dependent on the availability of suitable coal seams.
• Carbon Mineralization:
  • The technology is still in early stages. Scalability is uncertain but has potential, especially if integrated with industries producing calcium or magnesium as byproducts.
• Carbon-negative Concrete:
  • The construction industry is massive, and widespread adoption could sequester billions of tonnes, but this requires global shifts in industrial practices.
• Blue Carbon:
  • Limited scalability compared to the 10 Gt target because the total area of these ecosystems is small compared to what would be needed.
• Ocean Alkalinity Enhancement:
  • Scalability is uncertain and requires extensive research to ensure no unintended ecological consequences.
• Seaweed Farming:
  • While seaweeds grow rapidly, achieving billions of tonnes of sequestration would require vast ocean areas and robust infrastructure for harvesting and sinking.
• CCS:
  • Has been demonstrated at the scale of millions of tonnes. Achieving billions would require significant investment and infrastructure, but it's one of the more mature and scalable technologies available.

In conclusion, no single method seems ready to sequester 10 Gt of carbon annually by itself without significant challenges. A combination of multiple methods, along with continued emissions reductions and shifts to renewable energy, is likely the most realistic approach to meet the target. The feasibility of each method will also depend on technological advancements, investment, policy support, and global cooperation.


1. One of the problems with CCS is that Net Zero requires the sequestration of all anthropogenic carbon. CCS alone can't be applied to all emitters, many are unsuited and many are sited in countries which will not participate. 2. I don't believe there is a technological route to direct capture on the scale required but by all means extend the idea if you feel it might. Consider the same issue for weathering. 3. Reforestation and biomass both conflict with the equally essential need for wildlife extension to avoid biodiversity collapse, alongside farming demands.



Given the constraints and concerns you've mentioned:

• CCS's limitations:
  • You're correct. Many emitters aren't suited for CCS, either due to technological, economic, or geopolitical reasons. While CCS can be applied to large point sources like power plants, it's challenging to implement for distributed sources such as vehicles, small-scale industries, and residential heating.
• Direct Air Capture and Enhanced Weathering:
  • Direct Air Capture (DAC): While current technology might not be scalable to 10 Gt of carbon annually, advancements in technology and energy efficiency might make it more viable in the future. For instance, improvements in sorbent materials or integration with renewable energy sources could make the process more efficient. Still, achieving such scale would be monumental.
  • Enhanced Weathering: The idea involves accelerating a natural process, but on the scale required, it would involve significant land disruption and energy. As with DAC, while theoretically possible, the scale needed presents major logistical challenges.
• Reforestation, Biomass, and Biodiversity:
  • Afforestation and BECCS do present land-use challenges. The large-scale cultivation of biomass, especially if not managed sustainably, can reduce habitat availability, leading to biodiversity loss. Reforestation, if not done with ecological considerations, can also reduce biodiversity by creating monocultures or displacing native species.

Considering the constraints and the need for a solution, a multi-faceted approach might be the most effective:

• Urban Greening:
  • Expanding green spaces in urban areas can sequester carbon and provide habitats without conflicting with natural ecosystems or agricultural lands.
• Regenerative Agriculture:
  • This approach to farming enhances soil health, increasing its carbon storage capacity, and promoting biodiversity. By adopting these methods, we can produce food, sequester carbon, and support ecosystems simultaneously.
• Carbon Mineralization:
  • While still in its early stages, if integrated with industries that produce calcium or magnesium as byproducts, there's potential for scalability.
• Carbon-negative Materials:
  • Beyond just concrete, innovations in materials that absorb CO2 during their lifecycle can be explored. These can be used in construction, manufacturing, and other industries.
• Blue Carbon Enhancement:
  • While the total area might be limited, protecting and expanding mangroves, salt marshes, and seagrass meadows can sequester carbon and support biodiversity.
• Technological Innovations:
  • Investment in R&D can lead to breakthroughs in new methods or improve the scalability and efficiency of existing ones.
• Policy and Behavioral Change:
  • Promoting policies that reduce emissions at the source, such as transitioning to renewable energy, increasing energy efficiency, and encouraging sustainable consumption can reduce the amount we need to sequester.

Given the urgency and scale of the challenge, it's crucial to adopt a diversified approach, leveraging multiple strategies in tandem while investing in research and innovations that could provide breakthrough solutions.


You mention urgency and indeed the deadline is 27 years from now. Advancements in technology and energy efficiency might make it more viable in the future but it is hard to imagine how current blue-skies research can give rise to industrial maturity at that scale in the time frame. If you were to plan a route to achieve this level of sequestration, consider that it needs to handle a half of all emissions while the other half of our current excess will be removed by renewables. It is clearly helpful if at least some anthropogenic output is sequestered on a rising basis between now and 2050 but the one essential is that it should be fully scaled by that date.



Meeting the 10 Gt carbon sequestration goal by 2050 is indeed an immense challenge, especially given the time constraints for implementing blue-sky research into mature, scalable industries. A robust plan should therefore focus on both scaling up current feasible technologies and fostering emergent ones that have a clear path to rapid deployment.

Here’s a broad roadmap:

• Maximize Deployment of Current Scalable Solutions:
  • Carbon Capture and Storage (CCS): For all its limitations, it's one of the most mature technologies. Focus on industries and regions where it's most feasible and where there are large point sources of CO2.
  • Carbon Mineralization: Increase R&D funding and create incentives for industries that produce relevant byproducts to integrate carbon mineralization processes.
  • Urban Greening: Encourage cities globally to adopt aggressive tree-planting and greening campaigns. This not only sequesters carbon but also offers immediate local benefits, making it more politically palatable.
  • Regenerative Agriculture: Promote and subsidize this on a global scale. It offers multiple benefits—increased yields, resilience against climate events, and carbon sequestration.
• Invest in R&D for High Potential Technologies:
  • Even if they’re blue-sky now, some technologies might become feasible quicker than others. Prioritize those with clear benefits, fewer logistical hurdles, and potential for high carbon capture rates.
  • Direct Air Capture (DAC): Even with its current limitations, it has the advantage of being deployable anywhere, decoupled from emission sources.
• Incentivize Private Sector Participation:
  • Implement carbon pricing mechanisms (carbon taxes or cap-and-trade systems). Make it economically favorable for industries to invest in carbon sequestration.
  • Offer tax breaks or subsidies for companies that develop and deploy carbon capture technologies.
• Global Collaboration and Knowledge Sharing:
  • Form international alliances to share R&D findings, best practices, and policy strategies. Some solutions might be more effective in specific regions and can be scaled up faster with global support.
• Integrate with Renewables:
  • The switch to renewables should be pushed aggressively. Every unit of energy from renewables is one less that needs to be offset. Moreover, excess renewable energy during peak times can be channeled into energy-intensive sequestration processes.
• Policy and Education:
  • Strengthen international agreements and local policies that promote sequestration and emission reductions.
  • Run global education campaigns about the urgency and the available solutions to ensure public support and understanding.
• Infrastructure and Logistics:
  • Beyond just the capture/storage technologies, we need to invest in the infrastructure to transport captured CO2 and store it, whether underground, in mineral form, or other means.
• Continuous Monitoring and Feedback:
  • As technologies are deployed, continuous monitoring will be crucial. Adapt the approach based on which strategies are working best and scale those up further.

It’s essential to be realistic about the sheer scale of this challenge. This roadmap won't be easy, nor cheap. However, with global collaboration, adequate funding, and sustained political and public will, progress is possible. As the roadmap unfolds, it's essential to remain flexible, adapting to new technologies, learnings, and challenges that arise.


I have good statistics for CO2e emissions per year. I would like to begin tracking sequestration volume by year. Can you suggest reliable sources for that? There must be bodies tasked with collating and publishing the data.



Tracking carbon sequestration statistics can be a bit trickier than emissions since the industry and the data around it are newer and less standardized. However, various international organizations, research institutes, and governmental bodies do collect and publish data on carbon capture and sequestration (CCS) and other related topics.

Here are some reputable sources where you might find relevant data:

• Global CCS Institute: They provide one of the most comprehensive databases on CCS projects worldwide, including detailed information on the status, capacity, and technology of each project.
• International Energy Agency (IEA): The IEA has extensive reports and datasets on energy and CO2 statistics, including some dedicated to carbon capture, utilization, and storage.
• U.S. Department of Energy's National Energy Technology Laboratory (NETL): While U.S.-focused, NETL conducts extensive research on CCS and releases regular reports on the topic.
• Carbon Capture & Storage Association (CCSA): This UK-based organization also provides data and insights on the development of CCS globally.
• United Nations Framework Convention on Climate Change (UNFCCC): They collect and publish data on various carbon mitigation methods, including sequestration, as part of their national reporting requirements.
• European Commission's Joint Research Centre: For information specific to Europe, their reports might be beneficial.
• Carbon Dioxide Removal (CDR) databases: Given the emerging importance of direct air capture and other CDR techniques, you might find databases and repositories dedicated to tracking these projects. These are typically managed by research institutions or collaborative efforts.
• Scientific Journals: Keep an eye on journals like "International Journal of Greenhouse Gas Control" or "Carbon Management." Scientists often publish updated data and findings on CCS and other sequestration methods here.
• World Resources Institute (WRI): They provide extensive datasets and analyses on various environmental topics, including carbon capture and sequestration.
• Food and Agriculture Organization (FAO): For data related to carbon sequestration in forests and agriculture, FAO's Global Forest Resources Assessments and other publications might be of interest.

When tracking sequestration volumes, it's crucial to approach the data critically. Definitions and measurement methods can vary, so ensure you're comparing like with like. Furthermore, the industry is rapidly evolving, so staying updated with the latest research and data will be essential.


That sounds like a full time job for an intern.



It indeed can be! Monitoring and tracking carbon sequestration data across multiple platforms is a comprehensive task. Depending on the depth and specificity of the information you need, an intern or a dedicated researcher could spend significant time collecting, analyzing, and reporting on the data.

However, if you're looking for a more streamlined approach:

• Set Clear Objectives: Define what specific data points or metrics you are primarily interested in. Do you want global figures, specific regions, or specific types of sequestration (e.g., forestry vs. CCS)?
• Choose Primary Sources: Based on your objectives, identify one or two primary sources that are most relevant. For broad and updated global CCS statistics, the Global CCS Institute and IEA might be sufficient for most needs.
• Set a Schedule: Instead of continuous monitoring, you could decide on regular intervals (e.g., quarterly, biannually) to check and update your data.
• Use Automated Tools: Consider setting up alerts or RSS feeds for specific reports or publications from these sources. This way, you're notified of updates without having to manually check.
• Collaborate: If you're part of a larger organization or network, see if others are interested in the same data. Pooling resources or sharing the task can make it more manageable.
• Consider Outsourcing: Depending on the importance of this data for your work, it might be worth contracting a research firm or consultant specializing in carbon sequestration to provide regular updates or reports.

Remember, while the landscape of carbon sequestration is complex, with clear objectives and a systematic approach, the task can be made more efficient and manageable.


I will assume someone else is doing this already and publishing up to date releases on Github. I'll search there.



That's a reasonable assumption. GitHub and similar platforms are often used by researchers, non-profits, and other organizations to share datasets, tools, and reports with the public. Searching there could yield repositories where enthusiasts and experts alike collate and maintain updated information on carbon sequestration and related topics.

When searching on GitHub:

• Use Specific Keywords: Start with terms like "carbon sequestration data", "CCS dataset", "carbon capture statistics", etc.
• Check the Repository's Activity: Look for repositories that have been updated recently and have active contributors. This suggests that the data might be up-to-date.
• Verify the Source of Data: Ensure that the data in the repository comes from reputable sources. Often, the maintainers will mention where they sourced their data.
• Engage with the Maintainers: If you have questions or need clarifications, don't hesitate to open an issue or contact the repository's maintainers. The GitHub community is often very responsive.
• Fork and Follow: If you find a particularly useful repository, you can "fork" it to have your own copy and "star" or "watch" it to receive updates when new data or changes are pushed to the repository.

Your assumption aligns well with the collaborative and open-source spirit of platforms like GitHub. Hopefully, you'll find a repository or project that meets your needs!


Thank you for helping me focus my attention on what seems a difficult conundrum. I'm sure we'll discuss this further.



You're welcome! The challenge of carbon sequestration and achieving net-zero emissions is indeed complex, but with dedicated focus, collaboration, and innovation, progress can be made. I'm here whenever you'd like to discuss further or explore any other topics. Best of luck with your endeavors, and feel free to reach out anytime!

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What weight of grain is produced annually worldwide?



As of my last update in 2022, the annual global production of cereals (which includes major grains like wheat, rice, maize, barley, oats, rye, millet, and sorghum) typically exceeds 2.5 billion tonnes.

However, it's important to note the breakdown:

• Maize (corn): Around 1.1 billion tonnes.
• Rice: About 500 million tonnes (in milled equivalent).
• Wheat: Roughly 750 million tonnes.
• Others (like barley, oats, millet, sorghum, etc.): This would make up the remainder and would vary each year.

These are rounded estimates and can fluctuate based on a variety of factors including weather conditions, agricultural policies, market dynamics, and technological advancements.

For the most up-to-date and detailed figures, the Food and Agriculture Organization (FAO) of the United Nations has a database called FAOSTAT which provides comprehensive statistics on agricultural production globally.


Even if the mass of straw exceeds the grain by 10 times, and all were sequestered without treatment, it would still only amount to 0.25% of the required figure. The major issue remains volume. The required primary process has to scale up without using inordinate areas of land or labor. I'm coming to the opinion that we need to find a sea-based solution, it leaves wildlife expansion space without putting pressure on food production.



Your reasoning is valid. When it comes to carbon sequestration, volume is indeed a significant challenge. Given the vastness of the oceans and their capacity, sea-based solutions do hold significant potential. Here are a few ocean-based carbon sequestration and mitigation techniques:

• Ocean Alkalinity Enhancement: By adding alkaline materials, like crushed limestone, to the ocean, you can increase its capacity to absorb and sequester CO2. It also has the benefit of mitigating ocean acidification.
• Seaweed Farming: Macroalgae, or seaweed, grow incredibly quickly and can absorb substantial amounts of CO2 in the process. When the seaweed dies, if it sinks to the deep ocean, that carbon can be sequestered for centuries to millennia. Seaweed can also be harvested and processed to create bioenergy with carbon capture and storage, leading to negative emissions.
• Enhanced Weathering in Oceans: This involves grinding up silicate rocks on land and then adding them to the ocean, where they react with CO2 to form bicarbonates.
• Ocean Fertilization: This controversial method involves adding nutrients to the ocean to stimulate phytoplankton blooms. When these blooms die and sink, they take carbon with them. However, this method has potential ecological side effects that aren't fully understood.
• Blue Carbon Ecosystem Restoration: Ecosystems like mangroves, tidal marshes, and seagrass beds are potent carbon sinks. Restoring and expanding these ecosystems can sequester carbon and provide other ecological benefits.
• Direct Air Capture and Storage in Seabed: While the technology is still in development, there's potential to capture CO2 from the atmosphere and then store it in rock formations under the sea.

Given the potential side effects and the complex nature of marine ecosystems, it's crucial to approach ocean-based solutions with caution. They must be deployed thoughtfully and based on robust scientific evidence to ensure they don't inadvertently cause more harm than good.

However, given the scale of the challenge, it's clear that a multifaceted approach that combines both land-based and sea-based solutions, along with aggressive reductions in emissions, will be necessary.


Seaweed grows in the shallows, getting it to the deep ocean is a challenge.



You're correct. While seaweed naturally grows in shallow waters, ensuring its long-term sequestration by transporting it to deeper ocean layers presents logistical and ecological challenges. Here are some considerations and potential strategies:

• Natural Sinking: Some species of seaweed, after their lifecycle, will naturally sink when they die. However, this isn't guaranteed for all seaweed, and often, it can remain in the upper layers, where it will decompose and release its stored carbon back into the atmosphere.
• Mechanical Sinking: This involves manually collecting and sinking seaweed to deeper ocean layers. Techniques could involve weighting the seaweed or processing it into forms that more readily sink. However, this would require significant energy and infrastructure.
• Anaerobic Digestion: Instead of sinking the seaweed, it could be processed through anaerobic digesters, converting it into biogas. The CO2 produced in this process could then be captured and sequestered. While this doesn't involve deep ocean sequestration, it's a way to use the seaweed for energy while capturing the carbon.
• Ecological Considerations: Sinking large quantities of seaweed to the deep ocean could have ecological impacts. It could potentially disrupt local ecosystems, cause oxygen depletion in certain regions, or have other unforeseen consequences.
• Economic Incentives: If seaweed farming becomes a significant industry, there could be economic incentives to harvest and process seaweed for various products (like food, fertilizers, or biofuels). While this might not directly sequester the carbon in the deep ocean, it could offer other pathways to utilize or store the carbon.

Given the challenges, while seaweed farming holds promise as a carbon sequestration method, it's essential to approach it holistically, considering both the potential benefits and the challenges. It might be one piece of a larger mosaic of solutions rather than a singular answer to the carbon sequestration challenge.


I will made a joke - processing through anaerobic digesters, converting the seaweed into biogas, would require a major investment in large plants.



Haha, I see what you did there! Using "plants" in both senses of the word—a clever play on words. It's essential to keep a sense of humor, even when discussing serious topics. If you have any other questions or jests, I'm here to help (or chuckle along)!


Does seaweed need to be anchored in order to grow? Is the growth process annual or continuous? Over what period does a mass of seaweed double?



Seaweed is a diverse group, so growth and anchoring mechanisms can vary across species. However, here's a general overview:

• Anchoring:
  • Most seaweeds anchor themselves to a substrate using holdfasts. These are not roots like in terrestrial plants, but structures that firmly attach seaweed to rocks, other hard surfaces, or even other plants. This anchoring allows seaweed to remain stationary in flowing water and resist the forces of waves and currents.
  • There are floating varieties of seaweed that do not anchor to the seafloor. The most well-known is the Sargassum species found in the Sargasso Sea, which spends its entire lifecycle free-floating.
• Growth Process:
  • Annual vs. Continuous: Some seaweeds have distinct annual cycles, growing in one season and dying back in another. Others, especially in more temperate or tropical regions, can grow continuously.
  • Some species, like the giant kelp (Macrocystis pyrifera), can grow incredibly fast under optimal conditions. Giant kelp, for instance, can grow up to 50 cm (around 20 inches) a day in ideal conditions.
• Doubling Time:
  • The period over which a mass of seaweed doubles (also known as the "doubling time") can vary greatly based on species, environmental conditions, nutrient availability, and other factors.
  • For fast-growing species like certain macroalgae or kelp under optimal conditions, the biomass can double in a matter of days to weeks. For other, slower-growing species, it might take much longer.
  • Nutrient availability is a significant factor. In regions with upwelling, where nutrient-rich deep water rises to the surface, seaweed and other marine plants can experience rapid growth.

Seaweed farming and cultivation practices often aim to optimize these growth factors, ensuring that the seaweed has the right conditions, nutrients, and light levels to maximize productivity. It's also worth noting that while seaweeds exhibit impressive growth rates, the specifics of growth will always be influenced by the unique environmental factors of a given region or cultivation setup.


Focus on Sargassum. What has prevented it from escaping its natural habitat and covering the world's oceans?



Sargassum, particularly the species found in the Sargasso Sea, is unique in its ecology and life cycle. The Sargasso Sea, located in the North Atlantic, is distinct because it's defined by ocean currents rather than land boundaries. Sargassum has evolved to thrive in this environment, but several factors limit its global dominance:

• Ocean Currents and Physical Barriers:
  • The Sargasso Sea is bounded by several major currents, including the Gulf Stream, North Atlantic Current, Canary Current, and North Atlantic Equatorial Current. These currents essentially keep the Sargassum contained within this "gyre" and prevent its widespread dispersion into other parts of the ocean.
  • While these currents can occasionally carry Sargassum outside of the Sargasso Sea, other oceanic conditions elsewhere may not be as conducive to its survival.
• Nutrient Availability:
  • The growth of Sargassum, like all plants, is limited by nutrient availability. The specific conditions of the Sargasso Sea, including periodic nutrient upwelling, support Sargassum growth. Other parts of the ocean might not offer the same consistent nutrient conditions.
• Predation and Competition:
  • In areas outside of the Sargasso Sea, Sargassum might face higher predation from herbivores or competition with local seaweed species adapted to those particular environments.
• Life Cycle Adaptations:
  • The Sargassum species in the Sargasso Sea are holopelagic, meaning they complete their entire life cycle while floating. This is a unique adaptation not commonly seen in other seaweeds. While it's advantageous in the Sargasso Sea, it might not confer the same benefits in other marine environments.
• Recent "Blooms" and Outbreaks:
  • It's worth noting that in recent years, there have been massive blooms of Sargassum in areas outside the Sargasso Sea, particularly in the Caribbean. These blooms have been linked to a combination of factors, including increased nutrient runoff from rivers, changing ocean currents, and warmer sea temperatures.
  • These events indicate that under certain conditions, Sargassum can indeed spread and grow rapidly outside its typical confines. However, these blooms, while extensive, haven't led to a global dominance of Sargassum.
• Climate and Environmental Factors:
  • Other parts of the world's oceans have different temperature profiles, light conditions, and salinities, which might not be as conducive to Sargassum growth and survival.

In summary, while Sargassum is well-adapted to its native environment in the Sargasso Sea, a combination of physical, ecological, and environmental factors has, so far, prevented it from achieving global dominance in the world's oceans. However, the recent blooms and changes in its distribution do highlight the potential for shifts in response to changing environmental conditions.


The idea that changing the limiting nutrients can trigger a bloom is good, and there are areas of the sea which are becoming abnormally warmer than in the past. All of that is tending toward the kind of exponential process we're looking for. Estimate the mass of a square km of fully developed Sargassum. Decide whether it naturally sinks at the end of its life cycle.



Let's break this down step by step:

• Mass of Sargassum:
  • Estimating the biomass of Sargassum per square kilometer can be a bit challenging as it varies depending on the location, time of year, and environmental conditions. However, research studies have provided estimates that can range from a few kilograms per square meter in dense patches to much less in sparser areas.
  • Taking a moderate estimate, if we assume there's an average of 1 kg of Sargassum per square meter in a dense patch, then a square kilometer (which is 1 million square meters) would have roughly 1 million kilograms, or 1,000 metric tonnes of Sargassum. This is a rough estimate, and real-world figures can be lower or higher based on the factors mentioned.
• Does Sargassum Naturally Sink?:
  • Sargassum, especially the species in the Sargasso Sea, is known for its floating habit, thanks to gas-filled bladders called pneumatocysts. These keep the seaweed afloat, maximizing sunlight exposure for photosynthesis.
  • Upon the end of its lifecycle or due to physical damages, parts of Sargassum may lose buoyancy and sink, but this isn't the typical fate for the majority of it. Most Sargassum decomposes at the surface, releasing its stored carbon back into the atmosphere or the surface layers of the ocean.
  • Only a small portion that sinks to the deep ocean would lead to long-term carbon sequestration.

If the goal is to leverage Sargassum's growth for carbon sequestration, several challenges need to be addressed:

• Ensuring Sargassum Sinks: The bulk of the seaweed would need to be transported to deeper ocean layers to ensure long-term carbon storage. This could require intervention, as naturally, most Sargassum does not sink.
• Nutrient Management: While adding nutrients can stimulate growth, it's a delicate balance. Excessive nutrients can lead to other environmental problems, like oxygen-depleted "dead zones" due to decomposing biomass.
• Ecological Impact: Expanding Sargassum growth could have unintended ecological impacts, including shading of the water column, which might negatively affect other marine organisms.
• Harvest and Use: Another avenue to consider is harvesting the Sargassum for bioenergy, with carbon capture and storage. This would allow the carbon in the seaweed to be utilized for energy while ensuring it doesn't return to the atmosphere.

Given its rapid growth and adaptability, Sargassum holds potential as a tool for carbon mitigation, but leveraging it effectively and sustainably requires careful consideration and planning.


Remind me of the legal process by which a government takes control of resources during a period of civil emergency. There's a technical term for it.



The legal process by which a government takes control of resources during a period of civil emergency is often referred to as "requisitioning" or "expropriation." In some jurisdictions, it might also be called "eminent domain," "compulsory purchase," or "compulsory acquisition."

Here's a general outline of the process:

• Declaration of Emergency: Typically, the first step is for the government to declare a state of emergency. This declaration provides the legal basis for taking extraordinary measures that might not be permissible under normal circumstances.
• Legal Basis for Requisitioning: Most countries have specific laws or statutes that grant the government the power to requisition property or resources in the public interest or for national defense. These laws will outline the conditions under which requisitioning can occur, the process to be followed, and provisions for compensation.
• Notice and Communication: Affected parties (e.g., property owners or businesses) are usually given formal notice that their property or resources will be requisitioned. This notice might include details about the reason for the requisition, the duration, and information about compensation.
• Compensation: While the government has the power to requisition resources in emergencies, there's typically a legal obligation to provide "just compensation" or "fair market value" to the affected parties. The exact amount and method of compensation can vary based on local laws and the nature of the emergency.
• Duration and Return: Requisitioned properties or resources are often returned to their original owners once the emergency is over. In some cases, properties might be damaged or consumed (e.g., fuel), which should be factored into the compensation.
• Legal Challenges: Affected parties might have the right to challenge the requisition in court, especially if they believe the action was unjust or the compensation inadequate.

The specifics of the process, including the rights of property owners and the obligations of the government, can vary significantly based on national laws, the nature of the emergency, and the resource being requisitioned.


Given the unprecedented need, assume the international community is granted requisition access to the Gulf of Mexico. It may be warm enough, its boundary is constrained, it can contain additional nutrients without damaging the environment beyond its limits, a skim process removing 40 million tonnes of weed a day to coastal power stations extracting the carbon. Assume half the surface area of the Gulf is available and an average cover of 200 tonnes of weed per square km, what fraction of the required sequestration can be processed? It's about the area of the gulf in square km divided by 400,000



Let's break this down step by step.

• Area of the Gulf of Mexico:
• The Gulf of Mexico covers about 1.5 million square kilometers.
• Available Area:
• If half of this area is available for Sargassum cultivation, that's 750,000 square kilometers.
• Total Sargassum Mass:
• With an average cover of 200 tonnes of weed per square kilometer, the total available mass is:
• 750,000 km^2 * 200 tonnes/km^2 = 150 million tonnes
• Daily Skimming:
• If 40 million tonnes of weed is removed daily, then the fraction of the total available mass removed daily is:
• 40 million tonnes/day ÷ 150 million tonnes = 0.2667 or 26.67%

Now, relating this to the required sequestration:

Given the initial discussions, the annual required sequestration is about 10 billion tonnes of carbon. To determine the fraction of the required sequestration achieved by the Sargassum process:

If 40 million tonnes of weed is processed daily, then annually (365 days) that is:

40 million tonnes/day * 365 days/year = 14.6 billion tonnes/year

Remember that this weight represents the weight of the Sargassum, not the carbon sequestered. If we assume (hypothetically) that 20% of the weight of Sargassum is carbon (which might be on the high side), then:

14.6 billion tonnes/year * 0.20 = 2.92 billion tonnes of carbon/year

Now, let's calculate the fraction of the required sequestration this represents:

2.92 billion tonnes of carbon/year ÷ 10 billion tonnes of carbon/year = 0.292 or 29.2%

Finally, regarding the area:

If you want to determine how many Gulf-sized areas are needed to meet the requirement based on area:

1 Gulf (750,000 km^2) divided by 400,000 gives 1.875. This means, in terms of area alone, 1.875 Gulf-sized areas would be needed to meet the sequestration requirement. However, remember that this is a simplified estimation and the actual sequestration efficiency would depend on various other factors.


It is simplified, and we only have one Gulf of Mexico. But you've just sequestered half the required carbon excess. And maybe the weed would give a denser mat. The design test is whether that volume of extraction plants and skimmers can be constructed over a 25 year period.



Certainly, achieving such a high level of sequestration through this method is promising in theory. The Gulf of Mexico, due to its size and constrained boundaries, could be a beneficial region to explore such a large-scale approach, provided that various ecological, environmental, and engineering challenges are addressed.

As for the feasibility of constructing the necessary infrastructure over 25 years, let's consider some factors:

• Scale of Infrastructure:
  • The number and size of extraction plants and skimmers required would depend on the specific design and efficiency of the technology. Given that 40 million tonnes of weed is processed daily, the infrastructure would need to be substantial and robust.
• Technological Development:
  • Existing technologies for seaweed harvesting and carbon extraction would likely need to be adapted or new methods developed to handle the enormous scale and unique conditions in the Gulf.
• Economic Investment:
  • Funding and economic incentives would play a significant role. Public-private partnerships, international collaborations, and possibly carbon credits could be explored to finance such a vast project.
• Environmental Impact Assessments:
  • Before any large-scale implementation, comprehensive environmental impact assessments would be essential to understand and mitigate potential negative effects on the marine ecosystem.
• Regulatory and Policy Framework:
  • As the Gulf of Mexico borders multiple countries, international cooperation and agreements would be necessary. There would be a need for a regulatory framework guiding operations, environmental protection, and potentially sharing benefits and responsibilities.
• Logistics and Supply Chain:
  • The supply chain for constructing and maintaining such a large-scale operation would be complex. From sourcing materials to building and deploying skimmers and extraction plants, comprehensive planning and logistics would be essential.
• Maintenance and Upkeep:
  • Over the 25 years and beyond, continuous maintenance, upgrades, and possibly expansions would be required. Ensuring the long-term sustainability and efficiency of the operation would be a priority.
• Public and Stakeholder Engagement:
  • Engaging with local communities, industries (like fishing), and other stakeholders would be crucial for the project's acceptance and success.

While the challenge is monumental, the urgency and scale of the climate crisis might warrant such ambitious endeavors. With global cooperation, technological innovation, and a focused approach, it might be possible to achieve the necessary scale within the 25-year timeframe. It would undoubtedly be one of the most significant engineering and environmental projects ever undertaken.


It's certainly the best we've arrived at so far. If it generates electricity while sequestering carbon then we added to the renewables for the bordering countries, but possibly that would involve a perpetual motion paradox - maybe sequestering doesn't make more energy than it uses.



Sequestering carbon and generating energy in the same process presents an intriguing concept, but it's essential to distinguish between the energy potentials and constraints in such a system.

• Seaweed as Biofuel:
  • Seaweed can be processed to produce biofuels, either through direct combustion, anaerobic digestion, or other chemical processes. In these scenarios, the energy stored in the seaweed (from sunlight via photosynthesis) is released. This doesn't create any "new" energy; it merely converts the energy from one form (biomass) to another (heat or chemical energy).
• Sequestration and Energy Production:
  • If the primary goal is carbon sequestration, then ensuring the carbon remains stored (and doesn't return to the atmosphere) is crucial. Burning the seaweed for energy would release its carbon. However, if the CO2 produced during combustion is captured and stored (Bioenergy with Carbon Capture and Storage - BECCS), then it's possible to generate energy while achieving net negative emissions. The challenge with BECCS is ensuring the carbon capture process is efficient and that the stored carbon doesn't leak back into the atmosphere.
• Energy Inputs vs. Outputs:
  • The energy required for the entire process—growing the seaweed, harvesting, transporting, processing, and sequestration—needs to be less than the energy produced (if any) to ensure a net positive energy gain. This is in line with the laws of thermodynamics; you can't get more energy out than you put in.
• Other Sequestration Methods:
  • Some proposed sequestration methods, like deep-sea storage of CO2 or mineralization, require energy. For these methods, an external energy source would be needed, making them potentially less attractive from an energy balance perspective unless powered by renewable sources.

In summary, while it's possible to use seaweed as an energy source, the energy balance becomes crucial if simultaneous carbon sequestration is the goal. For net positive energy production alongside effective carbon sequestration, the system's efficiency and the balance of energy inputs vs. outputs would need to be carefully optimized.


I would be happy to leave that to a university engineering department to analyze as an end of year thesis opportunity. And an oceanography institute to decide how to coax the Sargassum to grow in that environment.



Indeed, this sounds like an excellent multi-disciplinary project that could involve various academic departments across different universities. Given the scale and complexity of the challenge:

• Engineering Departments could focus on:
  • Designing efficient skimming and harvesting mechanisms.
  • Evaluating the energy balance and feasibility of various processing techniques.
  • Optimizing carbon capture and storage solutions.
• Oceanography and Marine Biology Institutes might delve into:
  • Studying the ecological implications of large-scale Sargassum cultivation.
  • Understanding nutrient cycling and the effects of external nutrient addition.
  • Exploring the life cycle of Sargassum and potential for controlled growth in new regions.
• Environmental Science Departments could investigate:
  • The broader environmental impacts, such as effects on local wildlife, water quality, and potential climate feedbacks.
  • Long-term sustainability and ecological health of the Gulf of Mexico.
• Economics and Policy Institutes can examine:
  • The economic feasibility of large-scale Sargassum cultivation and processing.
  • Policy frameworks, international agreements, and potential socio-economic impacts on surrounding communities.
• Chemistry and Material Science Departments might look into:
  • Efficient conversion processes of seaweed biomass to valuable products or biofuels.
  • Innovations in bio-refining and potential uses of by-products.

Offering such a project as an end-of-year thesis or even as a longer-term Ph.D. topic could spur innovation, foster collaboration, and potentially yield solutions that could be tested on a smaller scale. Engaging with academic institutions is a vital step in exploring innovative and out-of-the-box solutions to global challenges.


We need an ethics committee as well. I suspect sacrificing the ecological health of the Gulf of Mexico in exchange for meeting the 2050 targets worldwide is an acceptable trade-off but I could easily be mistaken.



An ethics committee would indeed be a critical component of such a project, especially given the potential trade-offs and unforeseen consequences of altering a marine ecosystem on such a large scale.

The ethical dimensions to consider might include:

• Ecological Impacts: The Gulf of Mexico is home to a rich diversity of marine life, including various species of fish, marine mammals, and countless other organisms. Sacrificing the health of this ecosystem could have cascading effects on biodiversity, some of which might be irreversible.
• Local Communities: Many communities along the Gulf's coast depend on its waters for their livelihoods, be it through fishing, tourism, or other industries. Altering the Gulf's ecology could have profound socio-economic implications for these communities.
• Climate Crisis: On the other side of the ethical equation is the looming threat of climate change, which poses existential risks to human civilizations and ecosystems worldwide. If this project could significantly mitigate those risks, it presents a strong argument in its favor.
• Unintended Consequences: Large-scale geoengineering projects often come with unforeseen side effects. The introduction of external nutrients might trigger harmful algal blooms or other unforeseen ecological shifts.
• Justice and Equity: Who gets to decide the fate of the Gulf of Mexico? Given the global nature of climate change, should the decision rest solely with the countries bordering the Gulf, or should it be a more international endeavor? This ties into larger questions about environmental justice and the distribution of burdens and benefits.
• Long-term vs. Short-term: Balancing immediate needs with long-term consequences is a perennial ethical challenge. The question becomes whether sacrificing the health of one ecosystem justifies the potential benefits for the global environment and future generations.
  
  Given these complexities, it's essential that any ethics committee involved in evaluating the project be diverse and include representatives from various fields: ecologists, local community representatives, indigenous peoples (where relevant), climate scientists, ethicists, economists, and more. Such a multi-faceted approach would help ensure that the decision-making process is comprehensive, just, and considers all potential impacts and stakeholders.