Global decline in net primary production underestimated by climate models

Area of Science:

• Marine ecology
• Oceanography
• Climate change science

Background:

• Marine net primary production is crucial for ecosystem services and the carbon cycle.
• Model projections of future net primary production changes lack consensus, hindering climate impact assessments.

Purpose of the Study:

• To evaluate and rank climate model projections of marine net primary production using contemporary remote sensing data.
• To identify shortcomings in current models regarding ocean warming impacts.

Main Methods:

• Utilized remote sensing net primary production trends (1998-2023) from six algorithms.
• Employed a model ranking scheme based on linear responses to sea surface temperature, chlorophyll-a, and mixed layer depth.
• Compared fifteen divergent model projections against observational data.

Main Results:

• Remote sensing data suggest future declines in marine net primary production are more probable than current models predict.
• The best-performing models still underestimate the sensitivity of net primary production declines to ocean warming.
• Existing models may not fully capture the amplified impact of rising sea surface temperatures.

Conclusions:

• Future marine net primary production declines may exceed current estimates, impacting ecosystem services.
• Improved model sensitivity to ocean warming is needed for accurate climate impact assessments.
• Greater accuracy in predicting temperature sensitivity could reveal even larger future declines in net primary production.