Taiwan university finds alkaline seawater helps reduce carbon

台灣大學發現鹼性海水有助於減少碳排放

TAIPEI (Taiwan News) — A new study from National Sun Yat-sen University found that ocean alkalinization can boost seawater’s carbon absorption capacity by 28% and slow the rate of ocean acidification by 14%.

The study, led by Assistant Professor Lui Hon-kit (雷漢杰), was published in the international journal Geophysical Research Letters. Lui’s team reported the results after analyzing 26 years of observational data from waters around Taiwan, suggesting the method could help mitigate climate change and protect marine ecosystems, per CNA.

Lui said the ocean naturally absorbs about 26% of human-generated carbon emissions through air-sea gas exchange, but this process leads to seawater acidification. The Intergovernmental Panel on Climate Change has emphasized that achieving net-zero emissions will require both carbon reduction and carbon capture technologies, with artificially increasing ocean alkalinity being one effective method.

However, previous efforts to enhance ocean alkalinity lacked long-term observational data, Lui noted. To address this, his team analyzed observational data on seawater pH levels and carbon content to evaluate the method’s effectiveness.

Huang Wei-jen (黃蔚人), a professor at the university, also led a team that developed carbon emission measurement instruments to monitor aquaculture in southwestern Taiwan. The findings were published in the international journal Science of the Total Environment.

The team found that milkfish ponds emit carbon throughout their entire farming cycle. In contrast, clam ponds absorb carbon when young clams are introduced, but begin to emit carbon from mid-cultivation to harvest.

Huang explained that clams feed on algae, which helps absorb carbon. However, adding feed to the ponds can lead to emissions due to the breakdown of leftover feed and other biological activity.