This study compares two policy instruments for decarbonizing China’s seafood exports to the EU and UK over 10 years using a recursive dynamic computable general equilibrium model. One instrument applies tariff-like carbon surcharges on embedded emissions at the border. The other recognises certified low-carbon production through tiered rate reductions or exemptions. The model constructs product-level carbon cost wedges for processing electricity, aluminium packaging, and cold-chain operations, then transmits them to border prices through pass-through and to import volumes through Armington demand. These mechanisms operate inside a dynamic setting with capital accumulation, learning, and technology adoption. We evaluate processed tuna, shrimp, whitefish, and fresh tilapia to reflect differences in energy use, packaging intensity, and cold-chain reliance. Results show that certification, especially when paired with targeted domestic green finance or tax offsets, speeds adoption of cleaner power and refrigerants and preserves market share better than uniform surcharges. Effects differ between coastal and inland production hubs, supporting location-specific policy bundles. Sensitivity analysis varies carbon prices, adoption speeds, and certification coverage within stated parameter ranges. We report trade, export revenue, emissions, investment, and welfare outcomes and identify product and channel drivers of exposure.

The growing incorporation of environmental policy into international trade has transformed the competitiveness of export industries and raised risks for carbon-intensive products. Focusing on China’s aquatic product exports to the European Union, this study examines how a CBAM-related carbon exposure index is associated with export performance and what this implies for trade competitiveness and adaptation. We construct an HS6-level panel for three aquatic product groups and three EU importers over 2015–2024, combining observed trade, tariff and macroeconomic data with constructed indicators of embedded carbon exposure derived from MRIO-based emission intensities and CBAM rules. Using a structural-gravity framework estimated with PPML (HDFE-PPML), we find a negative association between carbon exposure and export values in a simple specification, but this effect weakens and becomes statistically insignificant once richer importer–year and product fixed effects are introduced. Overall, the results suggest that the early CBAM transition has not yet produced a robust impact on China–EU aquatic trade, but they highlight emerging vulnerabilities for carbon-intensive products and the need for exporters and policymakers to pursue adaptation strategies that safeguard long-run trade competitiveness.