Harnessing Marine Algae: A Key to Combat Climate Change
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The Climate Imperative
The urgency to restrict global temperature rise to 1.5 degrees Celsius is becoming increasingly evident due to the escalating frequency of extreme weather events worldwide. For instance, notable occurrences include the heatwave affecting northwest North America in June 2021, the persistent drought in California, severe flooding in northern Europe in July 2021, record temperatures in the UK during July 2022, and flash floods in China the same month.
The IPCC's third assessment report on climate change mitigation emphasizes the significance of Carbon Dioxide Removal (CDR) technologies alongside reductions in greenhouse gas emissions to achieve this goal.
Emerging Solutions: Marine Algae
Among the various promising technologies, the utilization of marine algae for carbon capture is gaining traction. Brilliant Planet, located at the historic Rothamsted agriscience campus in the UK, has been actively engaged since 2013 in "unlocking the power of algae as a scalable, affordable, and immediate solution to climate change" (Brilliant Planet, 2022).
The innovative approach taken by Brilliant Planet involves cultivating substantial amounts of microalgae in coastal desert ponds using nutrient-rich upwelling ocean water, rather than relying on freshwater. This method effectively captures carbon through the photosynthesis of selected local algae strains, which are subsequently dried and stored by burying them deep underground at the site.
The company's journey began with a pilot project—a modest 3-square meter pond on Saint Helena Island in the South Atlantic. Today, they operate a vast facility in Morocco, which includes the world's largest algae growth pond, spanning thirty thousand square meters.
Brilliant Planet's system sets itself apart from other carbon capture technologies by employing natural ocean water, which is rich in nutrients and CO2, to support algae growth. This replicates the natural seasonal blooms of ocean algae that can rapidly cover extensive sea areas.
The natural process of algae consuming CO2 not only aids in carbon capture but also results in a reduction of acidity in the water left in the pond post-harvest. This more alkaline water is then released into nearby coastal waters, positively impacting local ecosystems, particularly in combating ocean acidification, which poses a threat to coral reefs and various marine organisms.
Brilliant Planet believes their technology could be implemented on any coastline, from Chile to Namibia and Australia, utilizing satellite remote sensing to evaluate potential sites. Their preference for coastal desert locations allows for extensive land use without conflicting with other activities, while proximity to the ocean facilitates efficient operations. Additionally, these microalgae facilities can stimulate economic growth in remote regions.
By exploring thousands of local algae strains, Brilliant Planet identifies the most effective options for cultivation without introducing invasive species or employing genetic modification (Brilliant Planet, 2022).
Although the website lacks detailed technical information regarding their accelerated algae growth process, it has been noted that their method could potentially capture up to 2 gigatons of CO2 equivalent. The importance of CDR technologies is highlighted as essential for maintaining a temperature increase within 1.5 degrees Celsius.
To provide context, the Intergovernmental Panel on Climate Change (IPCC) report outlines that global net anthropogenic greenhouse gas emissions reached 59±6.6 gigatons of CO2 equivalent in 2019, indicating a significant increase from previous years.
Historical Context of Photosynthetic Organisms
Throughout Earth's history, photosynthetic organisms, particularly microalgae, have played a pivotal role in sequestering carbon dioxide. The evolution of prokaryotic photosynthesis in cyanobacteria billions of years ago paved the way for eukaryotic photosynthesis in green algae and diatoms. These organisms have significantly altered the atmosphere by consuming CO2, fixing carbon in their structures, and releasing oxygen. Upon dying, they eventually settle at the ocean floor, forming marine sediments that trap carbon (Daneshvar et al., 2022).
Thus, leveraging marine algae for carbon dioxide capture represents a vital strategy for humanity in the fight against climate change and in minimizing the impacts of extreme weather events.
The first video titled "How Algae Could Change the Race to Save Our Climate" explores the transformative potential of algae in addressing climate challenges.
The second video, "Unlocking the Power of Algae to Capture CO2," discusses innovative methods for harnessing algae's capabilities in carbon capture.
References:
Brilliant Planet (2022) Brilliant Planet
Climate Change 2022: Mitigation of Climate Change (2022) IPCC report
Daneshvar, E., Wicker, R. J., Show, P. L., & Bhatnagar, A. (2022). Biologically-mediated carbon capture and utilization by microalgae towards sustainable CO2 biofixation and biomass valorization — A review. Chemical Engineering Journal, 427, 130884.