Trade protectionism undermines sustainable development in the Global South

The re-emergence of tariff-driven protectionism, exemplified by reciprocal tariffs, has redirected global attention toward the systemic challenges of green transitions, particularly in the Global South.1 However, despite strong domestic opposition in the United States and resistance from other major economies, which has led to repeated delays, the reciprocal tariff proposal has compelled several emerging economies to confront intensified tariff pressures in ongoing negotiations involving sectors such as agricultural products and South Africa’s critical mineral resources. Amid intensifying trade barriers, the Global South confronts new structural constraints in sustainable development, including heavy dependence on foreign green production techniques, a widening green financing gap, and institutional disadvantages within the global rule-making system. Recent studies have confirmed that China’s southeastern coastal regions and inland provinces with higher levels of vertical specialization have been disproportionately affected by US tariffs, while developed economies such as the European Union, Japan, and South Korea have benefitted from trade diversion effects.2 Tariff hikes disrupt the cross-border flow of technologies and services, potentially driving up global carbon emissions and reinforcing the view that trade protectionism systematically undermines the sustainable development of the Global South. Therefore, protectionist measures, exemplified by reciprocal tariffs, erode the South’s right to sustainable development by increasing the costs of green transitions, deepening high-carbon path dependence, and accelerating the cross-border displacement of emissions. This commentary develops a conceptual framework linking trade protectionism to sustainability outcomes in the Global South through green transition costs, carbon leakage pathways, and structural positions in global value chains (GVCs).

First, the costs of green transitions in the Global South may increase significantly. Reciprocal tariffs have directly weakened photovoltaic manufacturing exports from Southeast Asian economies, reducing their price competitiveness and raising production costs sharply. Since 2024, US tariffs on crystalline silicon photovoltaic cells from Cambodia, Malaysia, Thailand, and Vietnam have disrupted renewable energy supply chains. According to the Report of Solar PV Global Supply Chains proposed by International Energy Agency (IEA), these tariffs will increase solar project costs by 18% and reduce projected installation capacity by 12% by 2030. These shocks set the stage for future challenges to green development, with long-term effects on industrial structures and energy transition speeds across the region. However, even without these shocks, developing countries already encounter significant challenges in green technology innovation and energy system transformation compared to advanced economies. In many of these countries, tariff uncertainty heightens risks in critical areas, including green industrial investment, technology acquisition, and financing conditions. Unless high-income countries considerably expand access to green investment and climate finance, the Global South will find it difficult to achieve meaningful cost advantages in its green transition.