Small Island Developing States are facing worsening drought, water insecurity and threats to food production as the world approaches a possible breach of the 1.5°C warming threshold, the Alliance of Small Island States (AOSIS) has warned.

In a statement ahead of COP31, AOSIS described the prospect of exceeding the threshold as evidence of decades of climate inaction, arguing that island nations that have contributed least to global emissions continue to face some of the most severe consequences.

The statement pointed to the effects of an intensifying El Niño, which is worsening drought across island regions. In Palau, families are struggling to access safe drinking water, crops are under pressure and traditional crab harvests are declining, affecting livelihoods.

Parts of the Caribbean are also experiencing rainfall deficits that threaten freshwater supplies, agriculture and food security, while communities across the Pacific face the risk of severe food and water shortages.

AOSIS said the consequences extend beyond environmental indicators, affecting families’ ability to access basic necessities and maintain their livelihoods.

The group rejected suggestions that the prospect of temporarily exceeding 1.5°C should lead countries to abandon the target. It said the threshold remains the agreed temperature goal under the Paris Agreement and pointed to its affirmation by the International Court of Justice and the United Nations General Assembly.

AOSIS maintained that pathways remain available to limit the scale and duration of any overshoot and bring global warming back to 1.5°C, but said this would require immediate and sustained cuts in greenhouse gas emissions.

At COP31, the alliance intends to press developed countries and historical emitters to accelerate emissions reductions, implement the agreed transition away from fossil fuels and meet their climate finance commitments.

It is also calling for accessible, predictable and grant-based funding to support adaptation and emissions-reduction programmes, alongside an urgent replenishment of the Fund for Responding to Loss and Damage.

The statement said climate commitments would have little value without the financing needed to put them into practice.

Despite geopolitical uncertainty and political divisions, AOSIS said small island states would remain united in defending multilateral cooperation and pressing for their concerns to be addressed.

The alliance said COP31 must deliver concrete action on climate finance and emissions reductions, arguing that the science and solutions are already available and that governments must now demonstrate the political will to act.