Global climate governance and trade rules are shifting from a state of mutual non-interference toward one of intensifying frictions. As the decarbonization process deepens, the externalities of climate policies have triggered severe institutional conflicts. Unilateral measures — epitomized by the European Union's Carbon Border Adjustment Mechanism — nominally aim to prevent carbon leakage but, in practice, amount to trade discrimination. They gravely violate the principle of "common but differentiated responsibilities" and risk further widening the North-South trust deficit.

Confronted with conflicting stances, Brazil, holding the presidency of the 30th United Nations Climate Change Conference (COP30), displayed pragmatic diplomatic acumen and worked with developing and developed states to rebuild global consensus through the "Belém Political Package". By circumventing direct confrontation, the conference constructed an innovative framework of acknowledging disagreements while seeking cooperation, consisting of three core mechanisms.

First, through the "Global Mutir?o" — uniting humanity in a global mobilization against climate change — COP30 established a three-year standing dialogue mechanism on trade and climate, thereby breaking the long-standing taboo against addressing trade issues. Second, it created the Integrated Forum on Climate Change and Trade (IFCCT) as a non-binding platform linking the UN Framework Convention on Climate Change and the World Trade Organization, which are jointly governed by both the Global North and the Global South to rebuild mutual trust. Finally, it issued the Belém Declaration on Global Green Industrialization, calling for support to enhance local processing capacities in resource-producing regions, attempting to counterbalance the impact of trade barriers from the supply side through green industrialization and open new avenues for multilateral cooperation.

Although COP30 sought to rebuild multilateral cooperation in an era increasingly shaped by unilateralism, the practical challenges remain formidable.

The first challenge arises from the EU's leadership paradox. While the EU regards the CBAM as an indispensable environmental instrument, it has been denounced by the Global South as "green imperialism". Under mounting pressure, the EU has been compelled to accept the long-term dialogue mechanism embedded in the "Global Mutir?o" framework. This implies that its unilateral policies will be subject to continuous multilateral scrutiny, substantially raising their political costs.

Another major source of uncertainty stems from the volatility of the domestic politics of the United States. The US administration's retreat from climate leadership responsibilities and the absence of the US in multilateral mechanisms have deprived the Western camp of a unified leadership center and thereby severely undermined the IFCCT's effectiveness in mediating major-power trade frictions. These unilateral measures entail three structural traps. First, they violate principles of fairness by disregarding historical responsibilities and capability gaps, covertly shifting the costs of emissions reduction onto developing countries; second, they erect regulatory barriers, where steep compliance costs operate as non-tariff obstacles for small — and medium-sized enterprises; and third, they trigger a carbon leakage effect — clean products are redirected to specific export markets to evade tariffs, merely altering trade flows without generating genuine global emissions reductions.

For the Global South, the new framework established at COP30 is a double-edged sword. Its opportunity lies in the "Global Mutir?o" decision, which breaks the passivity long imposed on developing countries and grants them an institutionalized defensive shield, enabling them to use the annual dialogue to scrutinize the negative spillovers of unilateral measures. At the same time, the human-rights-based framework embedded in the notion of a "just transition" provides a legal foundation for their claims to financial and technical assistance.

Yet the structural predicaments facing the Global South remain daunting. Despite the Belém Declaration's pledge to support local green industrialization, industrial subsidies in developed countries are driving a reshoring of manufacturing, exposing Global South economies to the risk of being locked into the upstream end of raw-material exports. Meanwhile, the current climate finance architecture is profoundly imbalanced. The recently operational Loss and Damage Fund remains woefully insufficient relative to the actual needs of developing countries, and over 60 percent of climate finance takes the form of loans — conditions that will further exacerbate the debt crises of recipient states.

At COP30, China's diplomacy achieved a strategic shift from passive defense to proactive rule-shaping. Together with other BRICS countries, China successfully secured the formal inclusion of deliberations and restrictions on unilateral trade measures into the core resolutions of COP30. Furthermore, leveraging its leading position in renewable-energy technologies to offer an alternative as the West retreats, China has demonstrated its strategic resolve to uphold the multilateral process.

Looking ahead, China should engage deeply in reshaping the IFCCT and the global green supply chain. At the regulatory level, it should use multilateral platforms to promote mutual recognition of carbon-accounting standards, advocate for inclusive definitions of green products, and challenge the dominance of singular exclusionary frameworks. At the material level, it should accelerate the implementation of the Belém Declaration by shifting the global export of green capacity toward localized production, thereby circumventing rules-of-origin constraints and responding to the industrialization demands of the Global South. Ultimately, China ought to construct a composite strategy that combines normative leadership with the WTO dispute settlement mechanisms. By transforming South-South capacity cooperation into a demonstrable practice for development, China can claim the normative high ground. Simultaneously, by employing the instruments of international law, it can mount both legal and diplomatic pushback against discriminatory trade measures.

Yu Hongyuan is a professor at the School of Political Science & International Relations at Tongji University. Zhang Xiaoran is a doctoral candidate at the Law School at Shanghai University of Finance and Economics. The authors contributed this article to China Watch, a think tank powered by China Daily.

The views do not necessarily reflect those of China Daily. 

Contact the editor at editor@chinawatch.cn.