Earth Today | AOSIS, LDCs insist on 1.5 degrees goal

Across the Caribbean this year, Hurricane Beryl left farms in ruins and fields bare—a stark reminder of how climate extremes are already reshaping lives and livelihoods. For the world’s most vulnerable nations, these damages are not isolated events but part of an escalating pattern that makes the 1.5 degrees Celsius threshold a matter of survival, not preference.

At the 80th Session of the United Nations General Assembly on September 22, the Alliance of Small Island Developing States (AOSIS) and the Least Developed Countries (LDCs) pressed their case: keep global warming to 1.5°C and deliver the finance and policies to make that pathway real. Together, AOSIS’s 39 small island and low-lying coastal states and the LDC Group’s 44 countries speak for nearly a billion people living with the daily consequences of a heating world.

In their joint message, the groups emphasized that the 1.5°C guardrail is a non-negotiable line for safeguarding communities, ecosystems, and economies. They argued that the scientific evidence—and evolving interpretations of international obligations—requires governments to align targets and actions with this ceiling. Any overshoot, they warned, risks irreversible losses, from vanishing coastlines to collapsing freshwater security, and would reflect a failure of political will rather than a flaw in global agreements.

Closing the ambition gap before COP30

With the deadline for new climate pledges approaching, AOSIS and the LDCs called on all countries to submit updated 2030 targets and fresh 2035 targets by September 2025, consistent with a 1.5°C pathway. They urged that COP30 in Belém deliver a credible plan to close the gap between current commitments and what science demands, respond meaningfully to the Global Stocktake, and place the world firmly on course to meet the temperature limit. Marking ten years since the Paris Agreement, they said, should be about tangible progress, not ceremonial milestones.

Leadership from the two coalitions underscored the urgency. The AOSIS chair stressed that every fraction of a degree matters for island states already confronting existential risks. The LDC chair framed the issue plainly: delayed action translates directly into lost lives and livelihoods. Declarations are no longer enough—implementation must accelerate.

Adaptation first, with finance that reaches frontline communities

For vulnerable nations, adapting to the impacts already locked into the climate system is as critical as cutting emissions. Yet the gap in funding for adaptation continues to grow, and when resources do exist, they often fail to flow where they are needed most. The coalitions called for tripling adaptation finance by 2030 and delivering it in ways that are predictable, accessible, and scaled to match the challenge.

They also pressed for practical measures at COP30 to define what success looks like on adaptation. That means agreeing on indicators that reflect realities on the ground—from resilient water supplies to coastal defenses—so progress toward the Global Goal on Adaptation can be measured in ways that improve lives, not just tick boxes.

A finance architecture sized to the crisis

On broader climate finance, AOSIS and the LDCs demanded a New Collective Quantified Goal that meets actual needs rather than political convenience. They urged anchoring a $300 billion annual commitment within a “Baku-to-Belém” $1.3 trillion roadmap, complete with milestones, timelines, and accountability mechanisms to ensure delivery, not just pledges.

The coalitions also called for a fully funded and immediately accessible Loss and Damage Fund that prioritizes the most vulnerable countries. From storm-wrecked farms and flooded towns to saltwater intrusion and climate-driven displacement, the consequences of warming are already eroding resilience and straining scarce public resources. Rapid, reliable support is essential to rebuild, recover, and prevent cascading crises.

Why 1.5°C still matters

For small islands and least developed countries, the risks of passing 1.5°C are not abstract. Warmer seas amplify cyclones and fuel coastal erosion. Sea-level rise threatens homes, freshwater aquifers, and cultural heritage. Heat and humidity endanger outdoor workers and drive health burdens. Droughts and floods jeopardize food security, as seen when Beryl battered fields and destroyed crops across the region. Each fraction of a degree compounds these pressures, pushing critical thresholds closer.

This is why the two blocs insist that the 1.5°C target is not a bargaining chip. It is the foundation for a liveable future for hundreds of millions of people. Their ask is straightforward: align national plans with the science; ramp up mitigation to slash emissions this decade; finance adaptation at the scale required; and operationalize loss and damage support for communities already paying the price.

The road to Belém will test whether governments are willing to match words with deeds. For AOSIS and the LDCs, success looks like targets that add up, finance that gets where it must, and accountability that holds the system together. Anything less leaves the world’s most vulnerable to shoulder a crisis they did not create—and pushes the 1.5°C lifeline further out of reach.