New research has shown that by injecting an alkalizing agent into the ocean along the length of the Great Barrier Reef, at the current rate of anthropogenic carbon emissions, it would be possible to offset ten years of ocean acidification.
The study, conducted by CSIRO Oceans and Atmosphere, Hobart, used a high-resolution model developed for the Great Barrier Reef area to assess the impact of artificial alkalinization of the ocean on the acidity of the waters in the Great Barrier Reef.
to study. The study is based on using existing shipping infrastructure to inject a source of alkalinity into the ocean, which can also be thought of as accelerating the chemical weathering of minerals through natural processes.
Their results are published today (June 8, 2021) in the IOP Publishing journal Environmental Research Letters. The Great Barrier Reef is a globally significant coral reef system that supports productive and diverse ecosystems.
It is currently facing unprecedented stresses from ocean warming, tropical cyclones, sediment and nutrient runoff, marine pests and ocean acidification.
Among these stressors, ocean acidification poses one of the major threats to the long-term viability of the reef as it affects the corals’ ability to build and recover their hard structures and recover from bleaching events.
In response to the declining health of coral reef ecosystems, a wide range of potential intervention concepts and technologies are currently being considered, with the aim of minimizing environmental pressures and increasing the resilience of the coral reef ecosystem.
These include active and direct environmental approaches, such as artificial ocean alkalinization, a technique to offset or ameliorate the changes associated with ocean acidification, and improve oceanic carbon uptake.
Essentially, artificial alkalinization of the ocean involves adding a source of alkalinity, such as olivine, to seawater, “reversing” the shift in the carbon chemistry equilibrium process that occurs when the ocean takes up anthropogenic carbon.
Olivine is an abundant mineral resource, already being mined near the Great Barrier Reef. The aim of this study was to investigate the reduction of the impact of ocean acidification on a scale not previously considered.According to the authors:
“The majority of artificial modeling studies for ocean alkalinization to date have focused on the potential for alkalization as a technique for removing carbon dioxide.
Few studies have explored the role of alkalization with a focus on compensating for the changes. associated with ocean acidification on a regional scale.
” The study therefore used a recently developed coupled hydrodynamic-biogeochemical model with a resolution of 4 km, validated for the Great Barrier Reef area, to assess the impact of the alkalinity injection on individual reefs along the length of the Great Barrier Reef (~2,000). km) for the first time.
The results showed that by releasing the alkalizing agent from an existing shipping lane, the resulting deacidification would reach almost the entire Great Barrier Reef.
This report describes the new and timely use of a regional model as a testbed for a technique to combat ocean acidification.
The study found that by using existing shipping infrastructure (a bulk carrier delivering 30,000 tons per day) as the alkalinity supply mechanism, artificial alkalinization of the ocean would reduce the expected acidification by ten years on 250 reefs.
compensate or improve. In addition, it would also capture 35,000 tons of carbon per year in the ocean, or 0.0001% of current global CO2 emissions.