Warming could help make the Indian Ocean a stronger climate buffer

The Indian Ocean's role in mitigating climate change through carbon absorption is being impacted by shifting seasonal patterns, as suggested by new research published in Geophysical Research Letters. The study, conducted by Dr. Apurva Padamanbh Joshi and colleagues from the Indian National Center for Ocean Information Services, reveals that the Indian Ocean's capacity to absorb carbon dioxide (CO₂) from the atmosphere is changing, with significant regional variations.

The research found that the seasonal variation in CO₂ exchange increased by 48% in the equatorial Indian Ocean and 23% in the southern Indian Ocean, while it decreased by 14% in the Arabian Sea and increased by 7% in the Bay of Bengal. This indicates that the contrast between different parts of the year is becoming more pronounced in some regions of the Indian Ocean.

In the Arabian Sea, the average release of CO₂ into the atmosphere decreased, while absorption increased in the southern Indian Ocean. This distinction is crucial because a change in seasonal variation does not necessarily mean a region is absorbing more carbon overall. The changes in carbon exchange are primarily influenced by factors such as water temperature, winds, and ocean currents, which vary throughout the year.

The findings suggest that the Indian Ocean is not responding to climate change uniformly, with shifts in the timing and intensity of carbon exchange across the region. While the overall capacity of the ocean to absorb CO₂ has shown little growth since 2016, these seasonal changes could have implications for marine ecosystems. As CO₂ absorption changes, it can lead to increased ocean acidity, which may affect the ability of marine organisms like corals to build their skeletons and shells.

Understanding these evolving seasonal patterns is essential for predicting how the Indian Ocean will continue to act as a natural buffer against global warming. Although the study does not predict future changes, it highlights the need for further research to assess the long-term capacity of the Indian Ocean to store carbon as human activities continue to release CO₂ into the atmosphere.