From farms to oceans: How Microsoft is working to scale carbon dioxide removal

There is widespread recognition that efforts to meet global climate targets cannot be met by curbing new carbon dioxide emissions alone and will also require removing carbon from the atmosphere at scale.

Today, a wide range of advanced carbon dioxide removal projects are underway - and accelerating.

In Europe, construction is underway to enable carbon to be captured and condensed by Stockholm Exergi so it can be stored, beginning in 2028, deep under the North Sea. In the US, Lithos Carbon is spreading finely crushed volcanic rock across farmlands to convert carbon into bicarbonate ions that are stored for millennia deep in the ocean. And in Bolivia, Exomad Green is locking up carbon by processing sustainable forestry residues into biochar, a soil enhancement, using a type of thermal decomposition that was developed to break down organic materials in the absence of oxygen.

The goal is to help restore carbon balance lost through carbon dioxide emissions generated by modern life - from agriculture and construction to chemical and energy production.

Elementary school children are taught that plants remove carbon dioxide from the air through photosynthesis, so it's no surprise that initial carbon removal management efforts, beginning in the 1970s, focused mainly on planting and conserving trees. Today, scientists have much more insight into what generates carbon dioxide emissions and alternative methods to remove them.

Building on that knowledge, a growing number of carbon dioxide removal firms around the world are developing innovative projects, and Microsoft is helping build a market for those solutions at larger scale.

In fiscal year 2025, Microsoft signed agreements to remove a record 45 million metric tonnes of carbon dioxide with 21 companies across the globe. That's the equivalent of removing 9.8 million internal combustion cars from the road for a year.

Since the launch of Microsoft's carbon dioxide removal program, the pace and scale of projects have continually accelerated. Microsoft's carbon dioxide removal agreements in fiscal year 2025 are two times the volume contracted in the preceding fiscal year and nine times the volume contracted in fiscal year 2023. Projects span the globe, including ones in the US, Brazil, Denmark, Sweden, Bolivia, Norway, India, Panama, Canada and Switzerland.

And while this sharp increase in advance purchase commitments indicates rapid market advancement, there is a long road ahead to get to the seven to nine billion tonnes of carbon dioxide removal that experts say the world needs annually by 2050.

Microsoft has committed to become carbon negative by 2030 and to remove its historic emissions by 2050. The company takes a reduction-first approach. Carbon reduction is the most powerful lever for achieving carbon negative because it directly lowers emissions at the source, said Phil Goodman, director of the carbon removal portfolio at Microsoft. From there, carbon removal provides a direct pathway to address residual and historical emissions that cannot be mitigated through reduction. Microsoft advances carbon dioxide removal by signing contracts with carbon removal project developers to deliver volumes of high-quality carbon dioxide removal.

Key to this process is the carbon removal credit, representing the removal of one metric tonne of carbon dioxide. Credits are listed by project developers on registries, where they are bought by companies seeking to advance carbon markets and meet net-zero goals. Registration requires independent auditors to verify carbon removal claims according to the registry's methodology. Registries retain a public ledger to ensure transparency and prevent double counting so the credit cannot be used twice.

However, due to the small size of the carbon market, in the past several years Microsoft increasingly has worked directly with carbon dioxide removal suppliers during early stages of project design and development before they list their credits on registries. After conducting extensive due diligence, Microsoft invests to help develop innovation by signing contracts with carbon removal project developers.

"With any form of carbon removal, you need someone out there to buy the credits so that the economic model works," said Goodman. "By securing that forward demand commitment, suppliers can actually go raise financing, hire staff and build out their projects. We buy only a fraction of a project's total credits, and we hope other companies can make faster procurement decisions knowing that projects in our portfolio underwent deep due diligence."

Measurement is the essential backbone

Growing awareness of the harms of excess carbon dioxide in the atmosphere has spurred scientists to develop increasingly sophisticated methods for removing it and storing it safely - in soil, geologic formations, in trees and in the ocean.

Despite progress, carbon markets have also faced setbacks. In the last several years, scrutiny of credits generated by forest preservation projects helped lead to a regulatory crackdown.

To ensure the integrity of its program, Microsoft applies a rigorous due diligence process. Potential suppliers must submit comprehensive documentation detailing strategies for project design and implementation, methodologies, validation processes and other essential plans for addressing Microsoft's quality criteria.

"Measurement is the essential backbone of this industry, because there needs to be a common understanding of what a carbon credit means," said Goodman. "You're not buying a physical good. You're buying this environmental attribute that you need to feel confident can be consistently applied across project types, apples to apples."

Microsoft takes what it calls a "portfolio" approach, spanning a combination of nature-based and engineered solutions, which it believes is needed to catalyze market development, said Goodman. The company evaluates projects based on durability - or the length of time that carbon dioxide is expected to remain out of the atmosphere - including some that are expected to store carbon dioxide for less than 100 years to 1,000 years or longer.

Projects must show they will remove more carbon dioxide than they emit, to ensure that the net removal accounts for all operational and embodied emissions, and that local communities and ecosystems won't be negatively impacted by other parts of the process.

Enhanced rock weathering: Captured on the farm for storage in the ocean

Measurement is at the heart of Lithos Carbon, co-founded by two academics from Yale and Georgia Tech who helped pioneer monitoring, risk mitigation and verification of a process known as enhanced rock weathering to remove carbon dioxide and improve soil health.

The process begins with the sourcing of finely ground basalt, a type of volcanic rock that is widely available as a waste byproduct of quarrying and already used in composite materials for construction, roads and in other industries. Carbon dioxide removal depends on the chemical reactions that occur after the ground rock is spread over farmland, where it mixes with rainwater and atmospheric carbon to create stable bicarbonate ions. These ions then seep into waterways and rivers before heading out to sea, where they are stored for 10,000 years or more.

Lithos' approach accelerates and condenses a process that normally takes tens of thousands of years into a few seasons. "Essentially, we're helping nature do something it already does - just much faster," said Chief Executive Officer Mary Yap. Following an initial pilot project, Lithos and Microsoft signed a three-year contract in 2024 to remove over 11,400 metric tonnes of carbon dioxide.

Lithos uses high-density soil sampling and advanced laboratory analysis to make the invisible elements in soil visible, followed by AI-powered predictive modeling tools, water runoff samples and natural water chemistry to determine the end-to-end flow of bicarbonate ions from farms to waterways. Microsoft also assisted Lithos in creating a new, highly sensitive technique for detecting bicarbonate in rivers that originates from crushed basalt. Collaborating with Microsoft "helped accelerate the science and operational discipline that will help define the future of our work in this field," said Yap.

For farmers, the benefit is improved soil health, which leads to higher crop yields. "We roll up with a bunch of trucks," said Yap. "We spread this volcanic, nutrient-rich dust that restores their soils, reduces soil erosion and replenishes essential nutrients. It helps both farmers and the planet at the same time."

Regenerative farming: Capturing carbon while improving soil and crop yields

Changing farming and ranching practices offer other avenues for addressing and removing global greenhouse gas emissions. Excessive fertilizer use can lead to nitrous oxide emissions, a powerful greenhouse gas, while traditional tilling accelerates the oxidation of soil organic carbon, releasing it into the atmosphere as carbon dioxide. Tractors and other farm machinery burn fossil fuel. Given its size and impact, agriculture "is a sector that just cannot be ignored," said Dylan Lubbe, commercial director at Agoro Carbon Alliance, which works with the agricultural sector to store carbon.

To attack the problem, Agoro has recruited a small army of agronomists and other agriculture experts to help an expanding network of farmers and ranchers move away from traditional agricultural practices in favor of regenerative farming and ranching, a practice that removes carbon, improves soil health and boosts crop yields. It includes no-till soil preparation and the use of clover and other so-called cover crops with deep root systems that transfer atmospheric carbon into the soil through root biomass and microbial processes. Ranchers are encouraged to rotate animals to avoid over-grazing and stimulate plant growth.

"Soil is a natural carbon sink," said Lubbe. "Traditional agricultural practices disturb the soil, essentially letting that stored carbon dissipate into the atmosphere."

In June 2025, Microsoft reached an agreement with Agoro to purchase 2.6 million metric tonnes of carbon dioxide removals over 12 years. Extensive soil sampling validated by third parties is expected to confirm the project's carbon removal and storage and soil enhancement.

Agoro provides financial support for farmers and ranchers so they can feel more comfortable that changing to new farming and ranching methods won't hurt their bottom line. "It's very important to have a for-profit or market mechanism approach to a problem," said Lubbe. "If there's money to be made, then people are incentivized to address something."

BECCS: Bioenergy with carbon capture and geological storage

Another way to remove carbon dioxide is to capture it from burning biomass and store it underground in geological formations, using know-how first developed by the oil and gas industry. Stockholm Exergi, a Swedish energy giant, is addressing the complexity and high upfront costs of this approach by retrofitting its enormous bioenergy plant on the Stockholm waterfront so carbon dioxide can be captured by burning forestry waste from sustainably managed harvests.

Besides generating electricity, the plant already uses heat generated by its bioenergy process to warm the city of Stockholm. Now construction is underway to make it possible for carbon dioxide to be separated from flue gases and condensed so it can be transported by ship to the North Sea for storage. It will then be injected more than 800 meters beneath the ocean floor into porous bedrock, where it mineralizes over time. This elaborate process is known as bioenergy with carbon capture and storage, or BECCS.

"We are creating a flow of carbon from the atmosphere to the geosphere," said Erik Rylander, head of commercial operations at Stockholm Exergi.

In May 2025, Microsoft reached an expanded ten-year agreement with Stockholm Exergi to remove over 5 million metric tonnes of carbon dioxide. "This has never been done before at this scale and wouldn't have been possible without their commitment to buying our product," said Rylander. Working with Microsoft, "we are really trying to develop something that can become a market standard for BECCS."

Tropical reforestation: Drones and satellites replace tape measures

Harnessing trees to capture carbon dioxide has come a long way since the 1980s. While measuring the width of tree trunks with tape measures still plays an important role in the field, as was typical of early reforestation efforts, Brazil's re.green increasingly uses light-emitting drones and satellite imagery to monitor forest growth and carbon removal. Drones also distribute fertilizer and seeds over remote areas and steep hills. Satellite images and machine learning models help identify prime areas for reforestation.

To lock up carbon dioxide, re.green operates as an ecological restoration company, reclaiming lands that were deforested decades or even centuries ago. "Our effort is to restore the original ecosystem," said chief executive Thiago Picolo. "We're not just planting rows of trees." Their work ranges from selecting the most suitable native species for each landscape to sowing a diverse mix of seedlings to removing invasive exotic grasses and controlling ants that attack seeds and seedlings.

In January 2025, re.green and Microsoft reached an expanded agreement to purchase a total of nearly 6.5 million metric tonnes of carbon dioxide and restore a total of 33,000 hectares in the Amazon and Atlantic Forest biomes. "Scale is key to biodiversity, resilience and efficiency," said Picolo.

While trees consume carbon dioxide as they grow, they also release it as they decay, die or catch fire. Because their carbon-absorbing capacity also plateaus over time, re.green strategically harvests select native timber to maintain forest health for carbon capture and enhance biodiversity. While planting and sustainable harvesting also create local jobs, the priority is supporting the restoration of a healthy tropical forest.

"My dream, my Holy Grail, is not only for re.green to be a successful company, but for us to be a leader in a thriving, sustainable, new economic sector," said Picolo.

Top image: While planting and sustainable harvesting creates local jobs, re.green's priority is restoring healthy tropical forests. Photo provided by re.green.

Related links:

Learn more: Microsoft's carbon dioxide removal portfolio

Learn more: Microsoft's carbon dioxide removal program

Learn more: Microsoft's sustainability commitments

Sally Beatty writes about AI and innovation at Microsoft, focusing on the company's most cutting-edge breakthroughs and how emerging technologies are improving the lives of ordinary people. Previously, Sally was a feature reporter for the Wall Street Journal in New York, where she broke news about media and marketing. A California native, Sally lived in Hong Kong in the early 1990s, where she wrote for the Journal about the societal impact of economic and political reforms and consumer spending trends. You can contact Sally at LinkedIn .