Frequently asked Questions

Merely reducing CO2 emissions will not allow us to meet the targets of the Paris Agreement. We also need to remove CO2 from the atmosphere, particularly from agriculture and built environments which emittances are hard to reduce. We must start now to develop solutions capable of removing 10 GT per year by 2050.

Enhanced weathering is a form of CDR that involves the accelerated weathering of minerals to remove CO2 from the atmosphere.

Enhanced weathering works by increasing the rate at which minerals, such as olivine, react with CO2 in the atmosphere. The reaction converts the CO2 into bicarbonate ions, which can be stored in the ocean.

Some examples of enhanced weathering methods include spreading crushed minerals on land or agricultural soils, and injecting minerals into the ocean.

Enhanced weathering can remove CO2 from the atmosphere and thereby mitigate the effects of climate change. Additionally, it can also improve soil health and fertility, and provide a source of valuable nutrients for plants.

According to the IPCC Enhanced Weathering has a gigaton potential. Nevertheless, the weathering depends on a variety of factors, including climate conditions, the minerals applied and soil conditions. More field trials and data are therefore necessary. 

Enhanced weathering is one of the most promising CDR methods. While it holds potential as a solution to climate change, more research is needed to fully understand its potential and limitations.

Enhanced weathering is one of several proposed CDR methods and its effectiveness compared to other methods is still being researched. Advantages of Enhanced Weathering are its potential capacity to remove gigatons, the durability of carbon removal and its limited usage of energy.

The duration of Enhanced Weathering’s CO2 removal from the atmosphere varies based on factors such as method applied, mineral quantity, and reaction rate with CO2.

Yes, Enhanced Weathering can be used in conjunction with other CDR methods as part of a comprehensive strategy to reduce CO2 levels in the atmosphere.

The cost of Enhanced Weathering depends on a variety of factors, including the specific method used, the scale of implementation, and the cost of the minerals used.

Our approach utilizes sophisticated computer simulations co-developed with TNO to model the interactions between CO2, water, and dunite over time. These simulations estimate the potential CO2 capture and its conversion into carbonates on our rooftops, taking into account variables such as grain size, temperature, surface area, and chemical composition. This method allows us to optimize our green rooftops for maximum carbon sequestration efficiency.

Our LCA reveals that only 3.3% of the potential CO2 removal is offset by emissions during the manufacturing and maintenance of the rooftops, demonstrating a significant net positive impact on the environment.

Our Life Cycle Assessment (LCA) takes a conservative approach, as it’s likely that our supplier operates with greater energy efficiency than what is documented in the literature. Additionally, we haven’t factored in the emissions from the substrates that are being replaced. Therefore, the 3.3% emissions figure is likely an overestimate. 

We employ MRV protocols to monitor the CO2 removal performance, report our findings transparently, and verify the results with independent third parties, ensuring accuracy and reliability. Measurements are for instance soil and porewater measurements.

Our green rooftops can be installed on most flat and sloped roofs, provided they can support a minimum weight of 80 kg. For roofs with less structural strength, a lighter substrate option may be feasible, although this requires a case-by-case assessment to ensure safety and effectiveness.

Interested parties can contribute:

  • Installing our CO2-removing green rooftops on your buildings.
  • For municipalities, encouraging residents to adopt these green rooftops through subsidies or awareness campaigns.
  • Raising awareness about the importance of our green rooftops and the broader goal of carbon removal.
  • We are looking for a rooftop of 1-4 hectares to conduct further MRV-activities.
  • We are willing to provide further clarification on our services. Every action counts towards a greener future.

n the Netherlands, the law prohibits adding materials to the soil without the ability to remove them later. This is a key reason for our focus on rooftop applications. Moreover, for Enhanced Weathering (ERW), it’s crucial that the minerals remain in the soil to be effective.

Example, installing solar panels on roofs instead of setting up large-scale solar farms on agricultural land illustrates this point well. There are strict rules against using farmland for non-agricultural purposes. By placing solar panels on roofs, we make smart use of existing spaces without occupying additional land or violating regulations. Similarly, our CO₂-absorbing green roofs utilize existing rooftop spaces to contribute to environmental sustainability, without breaching existing laws.

Through careful optimization, including selecting the appropriate grain size and precisely controlling the amount of dunite applied per square meter, we ensure that the nickel content remains below the safety thresholds for water. This meticulous process ensures that our green rooftops contribute positively to CO2 removal without adversely affecting water quality.

We prioritize safety by ensuring the nickel content from our green rooftops stays well below the established water safety thresholds. Nickel is a metal that naturally occurs in both soil and water. Our approach involves using dunite responsibly, maintaining natural nickel levels without exceeding environmental standards. This careful balance allows us to harness the benefits of enhanced weathering while safeguarding environmental health.

Yes, at the end of their service life, the materials used in our green rooftops can be safely disposed of. About 90% of the dunite is weathered. The nickel remaining in the rooftop is below the thresholds for compost. This ensures that disposal is environmentally sound and complies with safety regulations, allowing the materials to be reintegrated without harm to the environment.

Our green rooftops include additional rocks and microbes that specifically react with CO2 to remove it from the atmosphere in a safe and permanent manner, contributing to national and international climate goals, making effective use of an as-yet unexploited area for climate activities, but also providing local environmental benefits. Green roofs are already known for their environmental benefits such as reducing urban heat island effect, improving air quality, and managing stormwater runoff, as well as improving urban biodiversity. Adding rocks for enhanced weathering combines this concept with a climate challenge technique to actively capture CO2 from the atmosphere.

Stichting Nationale Koolstofmarkt (SNK) is an organization dedicated to establishing a reliable and transparent carbon market in the Netherlands. It certifies CO2 reduction projects, providing a foundation for businesses and organizations to reduce their climate impact. Through strict quality controls and clear guidelines, SNK ensures the integrity and effectiveness of carbon compensations, supporting sustainable development goals and encouraging green innovations.

An SNK certificate verifies CO2 reduction or removal approved by SNK, with each certificate representing one ton of CO2 equivalent removed or saved. These certificates ensure investments in climate projects genuinely contribute to climate improvement, offering transparency and credibility in the carbon market.

In essence, SNK certificates offer organizations a verified method to contribute to global carbon reduction efforts while achieving their own sustainability objectives.

More specific:

  • Carbon Offsetting: By purchasing SNK certificates, organizations can offset their carbon emissions, contributing to their sustainability goals and commitments to becoming carbon neutral.
  • Sustainability Reporting: SNK certificates can be included in sustainability reports to demonstrate measurable action against climate change and showcase the organization’s commitment to environmental responsibility.
  • Enhancing Corporate Image: Leveraging the credibility of SNK-certified carbon reduction projects can improve an organization’s public image, highlighting its dedication to combating climate change.
  • Meeting Regulatory Requirements: Some industries may face regulatory pressures to reduce their carbon footprint. SNK certificates can help comply with these regulations by providing verified proof of carbon offsetting.Engaging Stakeholders: Using SNK certificates can engage customers, employees, and investors by showing tangible steps taken towards sustainability, potentially leading to increased loyalty and investment.
  • Engaging Stakeholders: Using SNK certificates can engage customers, employees, and investors by showing tangible steps taken towards sustainability, potentially leading to increased loyalty and investment.

The process of obtaining SNK certificates for CO₂ capture through olivine in green roofs involves several steps, focused on verifying and recognizing actual CO₂ reduction. Here’s a simplified explanation of the process:

  • Methodology Document Establishment: The methodology document, “CO₂-vastlegging middels olivijn,” will be formally established on May 3rd. This document outlines the guidelines and requirements for capturing CO₂ using olivine in building constructions.
  • Project Plan Submission: Our a project plan is already submitted detailing the expected CO₂ capture from our green roof projects. This plan is preliminarily reviewed to ensure it meets the criteria.
  • Validation: After May 3rd an external validator will assess the project plan to confirm its feasibility and compliance with the methodology document. This step ensures the integrity and reliability of the CO₂ capture project. (This has already been done in an informal way). 
  • Certificate Application in Batches: We will apply for SNK certificates in batches, either annually or when your production of green roofs reaches a minimum of 180 tons of removed CO₂. So, we expect the first credits to be issues end of 2024.
  • Certificate Allocation: For each approved green roof project, up to 60% (corresponding to the first period) of the verified removed CO₂ will be allocated in the form of certificates. This acknowledges and rewards the contribution to CO₂ reduction.

No, initially you get a discount where you transfer the right of the SNK-certificaten to CNI. If you opt in, you can purchase the SNK-certificaten when they are issued.

This depends on the production and distribution of green rooftops. However, we expect to issue the first credits in September.

No, in that case the SNK-certificaten remain with us and we sell them on the Voluntary carban credit market.

Unfortunately, that’s highly improbable. To qualify, you need to have an enormous roof of 10 hectares to be able to remove at least 1,000 tons of CO2 and meet various other criteria. This complexity is precisely why we undertake the rigorous process of verifying CO2 removal to secure SNK certificates.

While enhanced weathering is generally safe, and in most cases, beneficial to the environment, there are potential changes to soil and water chemistry that need to be pre-identified and monitored, which we are doing through our modelling approaches and our Alphen trial plots. These allow us to identify the greatest potential threats ahead of rooftop deployment and, where necessary, make changes to the feedstock size, amount or type (though the latter is unlikely to be a necessary step). We operate within the national environmental regulations as a company priority.