Direct Ocean Capture (DOC)

The ocean, the planet’s largest carbon sink, plays a crucial yet often overlooked role in combating climate change. It absorbs about 25% of all carbon dioxide (CO?) emissions and 90% of the excess heat generated by these emissions, helping to limit global warming.

The concept of Direct Ocean Capture (DOC) explores the possibility of enhancing the ocean’s natural ability to absorb even more CO? directly from the atmosphere. By boosting this capacity, DOC aims to accelerate the ocean’s role in reducing atmospheric CO?, potentially offering a powerful tool in the fight against climate change.

"Let's start with a bit of education"

Climate Change's greatest ally - the Ocean

The ocean plays a critical role in regulating Earth’s climate and sustaining life. It produces 50% of the oxygen we breathe, absorbs a quarter of all carbon dioxide (CO?) emissions, and captures 90% of the excess heat these emissions cause. Far from being just "the lungs of the planet," the ocean also serves as Earth's largest "carbon sink," absorbing CO? and buffering the climate against the worst impacts of emissions.

However, rising greenhouse gas emissions are straining this natural balance. They warm and acidify ocean waters, which harms marine ecosystems, threatens biodiversity, and undermines the ocean’s capacity to absorb CO?. This deterioration affects not only marine life but also life on land, as it reduces the ocean's ability to stabilize the climate.

"Protecting the ocean is crucial because it remains one of our most effective allies in climate solutions, offering a natural defense against emissions and the impacts of climate change."

Mangroves and Corals

Ocean habitats like seagrasses and mangroves play a critical role in combating climate change by sequestering carbon dioxide at rates up to four times higher than land-based forests. Mangroves are particularly rich in carbon, storing about 1,000 tonnes per hectare in their biomass and soils. Beyond carbon storage, mangroves support healthy fish populations, enhance water quality, and protect coastlines from floods and storms.

Coral reefs, covering less than 0.1% of the ocean, support over 25% of marine life and provide crucial benefits to around a billion people. They offer coastal protection, sustain fisheries, contribute to medicine, and generate tourism income. Expanding marine protected areas (MPAs), which currently cover 6.35% of the ocean, is vital for conserving these habitats and bolstering the ocean's resilience to climate change.

Ocean and Wind Energy

The ocean is a vast source of renewable energy, particularly through offshore wind and ocean energy, which harness natural forces like wind, tides, and currents. These energy sources are clean, meaning they don’t emit carbon dioxide or other greenhouse gases that contribute to global warming.

Offshore wind power is generated by wind turbines that capture airflow, converting mechanical movement into electricity. While wind energy has been used for centuries, recent advancements have greatly improved its efficiency. It’s projected that wind power could eventually provide over a third of the world’s electricity needs, positioning it as a primary global energy source. Denmark led the way in offshore wind development by building the first offshore wind farm.

Ocean energy, in contrast, uses the kinetic (movement) and thermal (heat) energy of seawater. Although this technology is in early stages, prototypes like wave and tidal current generators are showing promise. Ocean energy has the potential to generate far more than current human energy demands, offering a powerful solution for future energy needs.

Green Shipping

Around 80% of global trade relies on maritime shipping, but this industry contributes about 3% of the world’s greenhouse gas emissions. To help counter climate change, the goal is to reach zero CO? emissions from ships by 2050. Achieving this target requires a shift from fossil fuels to cleaner energy sources like hydrogen, ammonia, methanol, and even wind.

One promising approach is establishing “green shipping corridors”—maritime routes between ports committed to supporting zero-emission technologies for vessels. Green corridors, such as those linking Los Angeles and Shanghai across the Pacific and Antwerp and Montreal across the Atlantic, are already pioneering this shift. These corridors serve as models for low-emission maritime transport, showing how strategic routes can speed up decarbonization.

Investing in such clean technologies and supporting sustainable fuels can make green shipping more cost-competitive and catalyze global green development. This effort aligns with a broader "sustainable blue economy," where responsible trade and shipping bolster economic growth and public welfare without harming ocean health.

Coastal Communities

More than 680 million people—about 10% of the global population—live in low-lying coastal areas. These communities, especially on small islands and vulnerable coasts, face a 15-fold higher risk of death from floods and storms than those in more resilient regions. With rising climate threats, proactive ocean-climate actions are essential to protect these populations and build their resilience.

Effective strategies include adaptation measures like risk assessments, early warning systems, and sustainable, nature-based solutions to help communities respond to shifting coastlines and changing ecosystems. Early warning systems, which alert people to hazards before they hit, are particularly impactful: even a 24-hour warning can reduce potential damages by 30%. However, despite their importance, one-third of the global population—primarily in the least developed countries and small island states—lacks coverage by early warning systems.

In response, UN Secretary-General António Guterres has directed the World Meteorological Organization to ensure universal early warning coverage within five years, helping communities worldwide prepare for the intensifying impacts of climate change.

Now that we have been given a little bit of knowledge, we continue our journey through the landscape of Direct Ocean Capture

Industrial carbon capture systems have long been used to capture carbon dioxide (CO?) emissions directly from power plants and factories. These systems work by cleaning the flue gases—emissions released during energy production—before they can reach the atmosphere. However, Direct Ocean Capture (DOC) technology, which removes CO? from the atmosphere via the ocean, is much newer and still in its development phase.

To illustrate how DOC works, it’s useful to look at a few leading companies that are at the forefront of advancing this technology. These companies are developing methods to enhance the ocean’s natural carbon absorption abilities, aiming to remove more CO? from the atmosphere and support climate mitigation efforts. Exploring their innovations will give us a clearer picture of DOC’s potential in the fight against climate change.

Brineworks

An Amsterdam-based start-up is developing a technology that uses electrolysis, which splits water into oxygen and hydrogen, as a way to capture CO? from seawater. This process is projected to cost under $100 per ton of CO? when scaled up, making it more affordable than traditional Direct Air Capture (DAC) methods, which often exceed $200 per ton.

The technology is powered by renewable energy sources, such as solar and wind, ensuring the process is environmentally sustainable. Additionally, it only returns pure water to the ocean, with no harmful chemicals, keeping the ecosystem safe.

A unique feature of this approach is that it generates hydrogen as a by-product. As industries like steel and cement production seek cleaner energy alternatives, demand for “green” hydrogen (which is produced without emitting CO?) is expected to rise. This could offer a lucrative future revenue stream for the company.

Recently, the start-up, known as Brineworks, secured $2.2 million in funding to advance the development of this method, as reported by TechCrunch.

Captura

Captura, a spin-off from Caltech, is using a process called electrodialysis to capture CO? directly from seawater. In this method, ocean water is first acidified to release the CO? it holds. The CO? is then captured through a membrane. This process is powered entirely by renewable energy and avoids the use of chemicals or the generation of by-products, making it environmentally friendly.

Aiming to make the technology scalable, Captura plans to utilize existing infrastructure, such as desalination plants and decommissioned oil rigs, to keep costs low and streamline deployment. Supported by the U.S. Department of Energy and partnered with Norway’s energy company Equinor, Captura is running a pilot project in Hawaii designed to remove 1,000 tons of CO? annually. This pilot could pave the way for larger-scale CO? removal projects in the future.

Sea02

Sea02 utilizes a method called electrodialysis to extract CO? from seawater. This process involves separating the dissolved CO?, after which the captured CO? can either be stored underground (sequestered) or used in various applications. Once the CO? is extracted, the treated water is returned to the ocean, allowing it to continue absorbing CO? from the atmosphere, thus playing a part in carbon reduction.

The company, which originated from Delft University, is actively looking for storage partners in Europe to establish the necessary capacity for CO? sequestration. Sea02 has ambitious goals, aiming to remove 250 tons of carbon in the current year and increasing that amount to one million tons (a gigaton) by 2045. This scaling-up effort reflects their commitment to significantly contributing to global carbon reduction efforts in the coming decades.

Ebb Carbon

Ebb is a company that targets organizations involved in water processing, such as aquaculture farms, desalination plants, coastal industrial facilities, and ocean research laboratories. Their innovative technology works by taking in seawater and using low-carbon electricity to split it into two separate solutions: acidic and alkaline.

The alkaline solution produced in this process is then discharged back into the ocean. When this alkaline water mixes with seawater, it reacts with carbon dioxide (CO?) to form bicarbonate. This bicarbonate is a stable form of CO? storage, meaning it can effectively sequester carbon for thousands of years—up to 10,000 years, according to Ebb.

In addition to capturing CO?, Ebb's technology also plays a crucial role in lowering ocean acidity. This is significant because high acidity levels can be detrimental to marine life, particularly species such as fish and shellfish that are sensitive to changes in pH levels. Overall, Ebb's process not only helps in carbon capture but also contributes to healthier ocean ecosystems.

That's it for now. We'll be back soon with more sustainable Innovations. Did you like this post? Interested in more? Feel free to like and/or share with your network.