The ocean has long been Earth’s greatest ally against climate change, absorbing a staggering 31% of human-caused carbon dioxide emissions.1
However, this carbon sink may be reaching its limits. Ocean acidification has increased by 26% since 1850, a rate nearly 10 times faster than any period in the last 55 million years.2 This rapid change poses significant challenges for marine life, from microscopic plankton to massive coral reefs.
Scientists are now exploring controversial methods to enhance the ocean’s carbon absorption capabilities, including dumping massive quantities of alkaline chemicals into seawater. But what are the potential consequences of such drastic interventions?
A Risky Experiment?
The proposal is already facing significant opposition from local fishing communities and environmentalists concerned about the potential risks to marine life. Sodium hydroxide is a highly basic substance that can cause chemical burns, raising alarm about its impact if released in large quantities.
The researchers maintain that the chemical won’t have lasting negative effects, but critics argue that much more research is needed before “truckloads of liquid alkaline” are dumped in the ocean. Some see this as the type of thinking that led to the climate crisis in the first place—the notion that we can manipulate Earth’s systems without consequences.
The experiment would start with dispersing about 6,600 gallons of sodium hydroxide 10 miles south of Martha’s Vineyard this summer. If approved, a larger trial of roughly 60,000 gallons would take place next summer in the Gulf of Maine northeast of Provincetown.(ref)
Weighing the Pros & Cons
Proponents say OAE could help slow ocean acidification caused by absorbed carbon dioxide, which is damaging coral reefs and shellfish. They argue we must study such methods given the world’s sluggish transition away from fossil fuels.
Ocean alkalinity enhancement works by adding alkaline substances to seawater, which converts dissolved CO2 to bicarbonate and carbonate ions. This allows the surface ocean to absorb more CO2 from the atmosphere without further acidification. Modeling studies suggest OAE has significant potential to help meet climate targets, potentially removing up to 20 million tons of CO2 annually through water treatment outfalls alone.(ref)
However, others contend that to meaningfully impact climate change, OAE would need to be deployed on a massive global scale, with relatively minor carbon offsets compared to the energy-intensive process of producing and transporting the alkaline materials. There are also doubts about selling carbon credits for an approach that is not yet well understood.
The Path Forward
Ultimately, much more research is needed to fully assess the feasibility, effectiveness, and ecological impacts of OAE before any responsible larger-scale implementation can be considered. While enhancing the ocean’s natural carbon absorption is an intriguing idea, we must thoroughly investigate the complex implications and avoid unintended consequences.
Key areas requiring further study include:
- Determining optimal implementation methods to maximize efficiency and minimize risks
- Assessing impacts on marine species and ecosystems across different levels of biological organization
- Understanding how mineral particles move and dissolve in seawater
- Modeling the movement of alkalinized seawater in ocean surface layers
- Evaluating potential interactions with other environmental drivers
A combination of monitoring, modeling, laboratory experiments, and carefully controlled field trials will likely be necessary to answer these critical questions. Any field experiments must adhere to strict environmental monitoring protocols and operate within pH ranges considered safe for aquatic life.
As research continues, it’s crucial to remember that rapidly shifting away from fossil fuels remains an absolute necessity in combating climate change. Ocean-based carbon removal approaches like OAE should be viewed as potential supplements to, not replacements for, aggressive emissions reductions.
Source:
