The status of algal decarbonization in Southeast Asian region: a review

Abstract

Abstract Due to their autotrophic nature, algae capture large quantities of CO2 from the atmosphere and convert it to chemical energy in the form of biomolecules and cell mass for various applications. Such bio-based CO2 capture plays an important role in global carbon neutrality, while making innovative and sustainable food and industrial products for human and animal use. This review broadly illustrates the total CO2 emissions of the Southeast Asian region, named as the Association of Southeast Asian Nations (ASEAN), while estimating CO2 capture by regional commercial algae. Among all these nations, the top CO2 emitter in the ASEAN region is Indonesia (625 Mt yr−1) followed by Vietnam (311 Mt yr−1), Thailand (289 Mt yr−1), Malaysia (249 Mt yr−1), the Philippines (154 Mt yr−1), Singapore (52 Mt yr−1), Myanmar (49 Mt yr−1), Cambodia (16 Mt yr−1), Laos and Brunei (7 Mt yr−1). Indonesia is also ranked first in commercial algae production (9918 400 tons yr−1), followed by the Philippines (1500 326 tons yr−1) and Malaysia (188 110 tons yr−1). Similarly, the highest estimated algal CO2 capture is made by Indonesia (11 327 817 tons yr−1) followed by the Philippines (1705 871 tons yr−1) and Malaysia (214 279 tons yr−1), with other ASEAN countries having negligible algal CO2 capture due to either low algae production or a lack of data. The ASEAN region may play a pivotal role in the bio-capture of CO2 with the help of the phytoplanktonic aquaculture industry for value-added products. The rapid emergence of the algal industry in the ASEAN region was due to increased global demand for carrageenophyte seaweeds (98.63% of global), such as Eucheuma sp., from Indonesia and Kappaphycus alvarezii from Malaysia and the Philippines. Due to its tropical climate, high aquatic biodiversity, sufficient water and nutrient resources, and long coastlines, the ASEAN regional governments took prompt action and implemented policies for increased seaweed industry in the region. Conclusively, it is desirable to further strengthen the algal industry in these regional countries for useful products and efficient CO2 capture.