The oceans govern the Earth’s climate. But our current knowledge and data are not sufficient for us to effectively address several ocean crises. To prove the applicability of new technologies for ocean cleanup. The UNESCO Ocean Report 2024 states that new technologies should remove carbon dioxide from atmoshphere. Vidar Helgesen, executive secretary of the Intergovernmental Oceanographic Commission of UNESCO, pointed out the continued lack of adequate comprehensive and aggregated data to underpin design of effective solutions.
Oceans took in the Earth’s energy imbalance, leading to sustained levels of 0.32 ± 0.03 W/m² in the upper 2,000 meters of the oceans from 1960 to 2023, and an accelerated rate of 0.66 ± 0.10 W/m² in the past two decades. Irreversible changes, on centennial to millennial timescales, are expected to be caused by the continuing warming trend. The report indicates there is an urgent need to gather regular ocean warming data. To track ocean heat content and its impacts to support the efforts for the conservation of healthy and resilient oceans.
UNESCO : impact of human activites on ocean warming
The most significant impact from human-induced greenhouse gas emissions is increasing the Earth energy imbalance. The oceans absorb around 90% units of the Earth’s energy imbalance, resulting in a cumulative increase of 2,000 meters in their upper layers of ocean heat content. An increase in ocean heat content can reduce ocean mixing, further depleting the oxygen content in deeper waters, causing deoxygenation. Deoxygenation of the ocean can have long-term adverse impacts on marine ecosystems, the blue economy, and the livelihoods of coastal communities that are dependent on the oceans.
UNESCO: ocean acidification
The mean global surface ocean pH has declined at an average rate of 0.017-0.027 units per decade since the late 1980s, indicating ongoing concern with regard to ocean acidification. Although in 2024, there were 638 stations reporting pH around the ocean. Data coverage still remains poor, and the duration of observation is still insufficient for accurately determining trends. Most of the coastal areas are experiencing acidification over larger domains. Because of the interplay between natural processes and human activities, and longer-term data sets are needed to identify emerging trends.
Sea level rise remains one of the most evident and impactful manifestations of climate change, with the global mean sea level increasing at 3.4 ± 0.3 mm/year from 1993 to 2023. We need to monitor sea level rise on various scales better with advanced space-based and in situ observing systems in order to study and mitigate its impacts.
mCDR technologies: alerting seawater chemistry.
The mCDR technologies mentioned are those that involve manipulation of the marine carbon dioxide removal. In other words, it aims at removing carbon dioxide permanently from the atmosphere. The examples are the alteration of seawater chemistry. To change the ocean’s carbonate chemistry to help absorb more carbon and fertilizing the ocean with nutrients like iron to stimulate the growth of phytoplankton to remove carbon. Since 2020, mCDR’s enthusiasm driven by scientific publications. The emergence of new start-ups, and significant investments in the technology by the United States and the European Union.
With the increased enthusiasm, many questions remain about mCDR’s ability to amplify the ocean’s carbon sink, its response to the ocean carbon cycle, and the possibility of adverse impacts. Another paragraph of the report indicates increased interest in that area of restoring coastal blue carbon habitats, i.e., mangrove forests, seagrass meadows, and tidal salt marshes, to enhance carbon sequestration. However, doubt about the long-term success of such restoration remains.
Conclusion : the interconnected ocean crisis
The UNESCO State of the Ocean Report 2024 argues that enhanced observation and research. To fill data gaps and further our understanding of oceanic changes, will be crucial to address the intertwined crises of ocean warming, acidification, deoxygenation, and rising sea levels. To evaluate the effectiveness and possible risks of the new technologies associated with carbon removal.
