The 2025 Small Island Developing States (SIDS) report of the Lancet Countdown on health and climate change reveals the relationship between climate change and food insecurity: in 2023, an additional 2.7 million people across 26 SIDS experienced moderate or severe food insecurity due to the higher frequency of heatwaves and droughts. “The report makes it very clear: climate change is affecting health, food security, labour force, and the economies of SIDS more than in other parts of the world,” says CMCC researcher and co-author of the report Shouro Dasgupta. “What is more, these burdens are borne by nations responsible for less than 1% of the emissions that cause them.”

Small Island Developing States (SIDS) are among the most exposed to climate impacts – whether these be sea level rise, droughts, floods, or extreme events – yet contribute less than 1% to global emissions. A contrast that has seen them become both frontline victims and powerful advocates for stronger climate action.

The new 2025 Small Island Developing States report of the Lancet Countdown on health and climate change sheds light on the status of SIDS and the progress towards achieving the goals of the Paris Agreement by looking at the numbers behind specific indicators that track the relationship between health and climate change in SIDS.

One of these indicators, led by CMCC researcher Shouro Dasgupta and Professor Elizabeth Robinson of the Grantham Research Institute, LSE, tracks the impact of higher frequency of heatwaves and droughts on access to food and quantifies the number of people in SIDS who have become food insecure due to climate change.

“We combined FAO data with heatwave-day and drought-month anomalies compared to the 1981–2010 baseline,” says Dasgupta. “The use of this empirical methodology allowed us to examine whether the relationship between climate change and food insecurity has evolved over time.”

The headline finding is that in 2023 an additional 2.7 million people (4.9% of their combined population) across 26 SIDS,  which include some of the world’s smallest and most vulnerable countries from the Atlantic, Indian Ocean, and South China Sea, the Caribbean, and the Pacific for a combined total population of around 70 million people, experienced moderate or severe food insecurity due to the higher frequency of heatwaves and droughts.

According to the report, a higher number of heatwave days was associated with 5.74% higher moderate or severe food insecurity in 2023; while increasing frequency of droughts was associated with 3.53% higher food insecurity.

The report strengthens the evidence-base for some of the most vulnerable countries and should be situated alongside the idea that the 1.5°C target is legally binding, that fossil-fuel production may constitute an internationally wrongful act, and that a duty to make reparations can arise where causation is established.

For more information:

Georgiana M Gordon-Strachan, Shouro Dasgupta, et al., The 2025 small island developing states report of the Lancet Countdown on health and climate change: building resilience in the face of rising heat, The Lancet Global Health, 2026, 103961, ISSN 2214-109X, https://doi.org/10.1016/j.langlo.2026.103961