A newly published article in Nature Climate Change (Nature Portfolio) offers one of the most comprehensive assessments to date of how multiple climate-related stressors are reshaping the ocean.
Over the last six decades, the ocean has been undergoing not just one, but multiple simultaneous climate-driven changes. Warming, acidification, deoxygenation, and shifting salinity patterns are interacting in ways that reshape ocean conditions from the surface all the way to the deep ocean. Using a time-of-emergence approach applied across a suite of physical and biogeochemical observations, the study shows that compound climate impact-drivers are now emerging across vast regions, including the subtropical/tropical Atlantic, subtropical Pacific, Arabian Sea, and the Mediterranean.
Highlights:
- The ocean is changing silently — but much faster than we thought: vast regions of the global oceans are now undergoing simultaneous transformations over the past 60 years— warming, salinity changes, deoxygenation, and acidification. These compound changes, from global scale to regional scale, from the surface to the deep ocean, indicate that the ocean is entering a new climate state.
- Between 25% and 40% of the upper ocean already shows significant changes in at least two key properties. Some areas are reaching alarming levels, with about a quarter (~25%) of the ocean affected by at least three properties at the same time.
- Areas particularly affected: The most affected regions include the tropical and subtropical Atlantic, the North Pacific, the Arabian Sea, and the Mediterranean. These changes threaten marine ecosystems, fisheries, food security, and the ocean's capacity to absorb heat and carbon. Model-based analysis indicates that these compound changes are primarily driven by human-induced climate change.
- A new analytical framework, dataset, and tool now make it possible for climate scientists to detect these critical areas that are the most impacted by human-induced climate change, as well as help decision-makers guide marine protection policies.
Read the full article: https://lnkd.in/dhgMHvFH
See here for the dashboard and a video of the evolution of compound climate change since 1980s: http://www.ocean.iap.ac.cn/pages/dataV/dataV.html?navAnchor=dataV
This research is supported by ObsSea4Clim and OCEAN ICE
Cite as: Tan, Z., von Schuckmann, K., Speich, S. et al. Observed large-scale and deep-reaching compound ocean state changes over the past 60 years. Nat. Clim. Chang. (2025). https://lnkd.in/dKKyYXwc
Article from post on LinkedIn by ObsSea4Clim
Article written by Zhetao Tan Laboratoire de Météorologie Dynamique – IPSL
