The principle of multilateralism, the idea that shared global problems require collective solutions, is facing its greatest test in a generation. This foundational concept, which has sustained United Nations climate diplomacy for decades, is now under severe pressure from a rising tide of populism and geopolitical conflict. The future of international climate action hinges on its survival.
A Deal in Belém: Progress Under Pressure
The Cop30 UN climate summit in Belém, Brazil, last November served as a stark microcosm of these challenges. While the final agreement averted disaster, it left no party fully satisfied. The deal was widely viewed as too weak to drive the necessary cuts in greenhouse gas emissions, and critical discussions on roadmaps to phase out fossil fuels were relegated to a voluntary side agreement.
Nevertheless, the fact that a compromise was reached at all demonstrated a fragile but persistent capacity for progress. Despite dire geopolitical tensions, nations proved they could still find common ground within the multilateral UN framework. The alternative—a complete collapse of talks—was narrowly avoided, preserving the process for another year.
The Shadow of Unilateralism and the Threat from Afar
A significant, ominous silence hung over the negotiations in Belém: the absence of the United States under President Donald Trump. Having begun the process to withdraw from the Paris Agreement in January at the start of his second term, the US sent no official delegation. However, delegates were acutely aware that American influence could be felt from a distance.
This threat was crystallised weeks earlier at a critical meeting of the International Maritime Organisation (IMO). There, US officials employed aggressive tactics, including reported threats of visa revocations and trade sanctions, to oppose a new carbon levy on shipping. Australian billionaire and clean shipping campaigner Andrew Forrest condemned the behaviour as "thuggery." The IMO talks broke down, delaying the levy for a year.
While such tactics were not repeated at Cop30, the precedent has been set. Countries are now braced for a potential onslaught when IMO discussions resume, casting a long shadow over future multilateral environmental negotiations.
New Battlegrounds: Green Tariffs and Coalitions of the Willing
The strain on multilateralism is manifesting in new policy arenas. This month, the European Union will implement the world's first carbon border adjustment mechanism (CBAM). This "green tariff" will penalise high-carbon imports like steel from countries with lax emission controls. The EU argues it is a tool to encourage global cooperation, with Climate Chief Wopke Hoekstra stating, "The best CBAM is one you don't have to use."
However, many developing nations, led by China, view it as a unilateral and unfair trade barrier. They attempted, largely unsuccessfully, to have it censured at Cop30, highlighting a growing rift between developed and developing economies on the path to net-zero.
Frustrated by the slow pace of UN consensus, over 80 countries at Cop30 pushed for a legally binding agreement on fossil fuel phase-out roadmaps. When this failed, they activated a Plan B: creating their own forum for action. This "coalition of the willing" will see Colombia host a pivotal conference on phasing out fossil fuels this April. Such minilateral initiatives lack the universality of the UN but represent a pragmatic form of multilateralism in action, increasing pressure on laggard states.
The Rocky Road to Cop31 and Beyond
The next major test arrives at Cop31 in Turkey in 2026, where governments must confront the glaring inadequacy of their current national emission plans, which collectively put the world on track for a catastrophic 2.5C of global heating. The summit itself will be an unusual experiment, hosted by Turkey but largely steered by a joint presidency with Australia—a last-minute hybrid deal struck at Cop30.
As 2026 is likely to be another record-hot year, reliance on multilateralism may seem like grasping at a slim reed. Yet, the alternative—abandoning the framework to the vagaries of individual governments, many of them opaque autocracies, and the short-term impulses of capital markets—offers no viable path to a stable climate. A decade after the Paris Agreement, multilateralism remains the indispensable, if embattled, cornerstone of global climate action.
