What the Ocean Gives People Has Been Improving. High Emissions Would Reverse That, a Study Projects

Researchers have published an index that scores what people get from the ocean in 143 coastal countries and used it to project how those returns change under two emissions scenarios. The paper appeared Sept. 24, 2026, in Communications Earth & Environment.

The authors describe the Blue Well-being Index as a way to assess and predict ocean-derived well-being for those countries under climate change scenarios. Yaowen Zhang of Ocean College at Zhejiang University and Qutu Jiang of the University of Hong Kong are its joint first authors, and Guanqiong Ye, also at Ocean College, is the senior author.

The two halves of the paper point in opposite directions. Across the historical period it assessed, 2000 to 2021, the global average score improved.

The rest is projection: model output under named scenarios, not measurement. Under SSP5-8.5, the high-emissions scenario, the team projects the global index falling about 9% by 2100, with adverse effects in nearly 90% of coastal countries. Under SSP1-2.6, the climate-mitigation scenario, it improves by about 11% instead.

In the projections, the losses do not concentrate at one end of the income scale. Both low-income and high-income countries are disproportionately affected, most of all in the natural and social parts of the index.

The paper is open access. The work was supported by the Department of Science and Technology of Zhejiang Province and by China's Ministry of Science and Technology.