XPRIZE Carbon Removal 2025: Winners and How Their Tech Works

The XPRIZE Carbon Removal, generously funded by the Musk Foundation, stands as a monumental challenge, incentivizing global innovators to develop and scale up technologies that can effectively remove carbon dioxide (CO2) directly from the atmosphere or oceans. The ultimate goal is to help humanity reach net zero emissions and even reverse climate change. The 2025 competition has already awarded several milestone prizes, and the grand prize winners are poised to revolutionize the field.

The Urgency of Carbon Removal

Before diving into the winners and their technologies, it’s crucial to understand why carbon removal is so critical. Even with aggressive reductions in current emissions, scientists agree that removing existing CO2 from the atmosphere is essential to limiting global warming to 1.5°C. This is because CO2 persists in the atmosphere for hundreds of years, meaning that past emissions continue to contribute to the greenhouse effect. Carbon removal technologies offer a pathway to address this legacy pollution and create a more sustainable future.

Milestone Award Recipients

Numerous teams received milestone awards, showcasing a diverse range of approaches to carbon removal. These awards recognized promising technologies and helped teams accelerate their development efforts. Some notable areas include:

• Direct Air Capture (DAC): Technologies that extract CO2 directly from the ambient air.
• Ocean-Based Solutions: Approaches such as ocean alkalinity enhancement and seaweed farming that leverage the ocean’s capacity to absorb CO2.
• Mineralization: Processes that permanently store CO2 by reacting it with rocks to form stable minerals.
• Biomass Carbon Removal and Storage (BiCRS): Using biomass to sequester carbon, then permanently storing it.

Deep Dive into the Winning Technologies

While the specific grand prize winners for 2025 are still eagerly anticipated, let’s delve into the categories and explore examples of technologies that are leading the way in carbon removal.

Direct Air Capture (DAC)

Direct Air Capture technologies are gaining significant traction. These systems use specialized filters and chemical processes to capture CO2 from the air. The captured CO2 can then be permanently stored underground or used to create valuable products like building materials or fuels.

Climeworks, a pioneering company in the field, operates DAC plants in Iceland that capture CO2 and store it underground as rock. Their technology uses geothermal energy to power the process, making it carbon-negative.

Imagine DAC facilities dotting the landscape, slowly but surely pulling excess CO2 from the atmosphere. This is the vision that many in the carbon removal field are working towards. Scaling up DAC will require significant investment and technological advancements to reduce costs and increase efficiency.

Ocean Alkalinity Enhancement

Oceans naturally absorb CO2 from the atmosphere. Ocean alkalinity enhancement aims to accelerate this process by adding alkaline substances, such as crushed rocks, to the ocean. This increases the ocean’s capacity to absorb CO2 and helps to mitigate ocean acidification.

One approach involves dissolving minerals like olivine in seawater. The olivine reacts with CO2, forming bicarbonate, which is a stable form of carbon storage in the ocean. This method has the potential to store vast amounts of CO2 while also benefiting marine ecosystems.

Mineralization

Mineralization involves reacting CO2 with rocks to form stable carbonate minerals. This process permanently locks away CO2 in a solid form, preventing it from re-entering the atmosphere. A great example is enhanced weathering of silicate rocks spread on agricultural lands. Rainfall reacts with the silicate, binding with CO2 and eventually ending up in the oceans where, as described above, it increases alkalinity and sequesters carbon.

Biomass Carbon Removal and Storage (BiCRS)

BiCRS involves using sustainable biomass (organic matter) to capture CO2 through photosynthesis. The biomass is then converted into a stable form, such as biochar or biofuels, and permanently stored underground or used in long-lasting products.

One strategy includes growing fast-growing trees, harvesting them sustainably, and using the wood to create durable products like furniture or building materials. This effectively locks away the carbon stored in the trees for decades or even centuries. Critically, the harvested forests need to be replanted and well-managed to provide a continuous carbon “sink”.

The Future of Carbon Removal

The XPRIZE Carbon Removal 2025 is not just a competition; it’s a catalyst for innovation and collaboration in the fight against climate change. The winning technologies, and the many others being developed around the world, hold immense promise for a future where carbon removal is a core component of our climate strategy.

As these technologies mature and become more cost-effective, they will play an increasingly important role in achieving global climate goals. The XPRIZE is driving breakthroughs, inspiring entrepreneurs, and attracting investment to this crucial field. The journey to net zero and beyond is a challenging one, but with ingenuity and determination, coupled with sound public policy, the future will be more manageable.

What’s Important to Note

It is critically important to note that carbon capture technologies must be measured according to well-to-wheel accounting. Said differently, it’s not enough to just measure the amount of captured carbon but also the energy used in the process, which must be calculated into the total carbon footprint impact or the effort is for naught. Further, carbon capture must never be viewed as a substitute for eliminating carbon emissions by converting to sustainable energy sources.

The Road Ahead

The XPRIZE 2025 is expected to be an inflection point for carbon removal. It will help bring awareness to the need for carbon neutrality and the technological capabilities that exist. It is necessary to develop viable ways to lower global temperatures, but it isn’t easy. With increased funding and ingenuity, it is conceivable to find pathways that create a sustainable climate in the immediate future.

Table of Carbon Capture Methodologies

Technology	Description	Advantages	Disadvantages
Direct Air Capture (DAC)	Extracts CO2 directly from the atmosphere using specialized filters and chemical processes.	Can be deployed anywhere, potentially high removal capacity.	High energy consumption, expensive, potential environmental impacts from solvents.
Ocean Alkalinity	Enhances the ocean’s natural ability to absorb CO2 by adding alkaline substances, increasing its CO2 uptake capacity.	Potential for large-scale removal, mitigates ocean acidification.	Potential ecological impacts, requires careful monitoring.
Mineralization	Reacts CO2 with rocks to form stable carbonate minerals, permanently storing CO2.	Permanent storage, stable end-product, can use abundant materials.	Slow reaction rates, requires large land areas, potential environmental impacts from mining.
Biomass Carbon Removal and Storage (BiCRS)	Uses biomass to capture CO2 through photosynthesis, then converts it into a stable form and stores it permanently.	Can produce valuable products, potential for co-benefits (e.g., soil improvement).	Requires sustainable biomass management, potential for land-use conflicts, risk of leakage if storage is not secure.