Lancet Countdown
New findings in the second indicator report of the Lancet Countdown Small Island Developing States (SIDS) reveal that people living in SIDS continue to bear a disproportionate and escalating health burden from climate change, despite collectively contributing less than 1% of global greenhouse gas emissions.
Authored by 30 experts from 25 academic institutions, the report highlights accelerating risks, while underscoring the urgent need for greater international support to build on action already underway.
Key Messages
Small island developing states pay the health price for global inaction on climate change
Collectively, SIDS produce less than one percent of global greenhouse gas emissions; however, their populations are facing severe impacts from climate change including intensifying heat, food insecurity, disease transmission and air pollution.
Small island developing state health response is strengthening, but progress is constrained without adequate international investment
SIDS are advancing climate and health action – expanding renewable energy capacity, strengthening early warning systems, and developing national climate and health plans. Yet these efforts remain far short of what is needed to protect and promote a healthy future.
Small island developing states are leading globally on climate diplomacy, law, accountability and youth-driven action
The landmark ICJ ruling affirming states’ obligations on climate action and reparations for harm was historic. SIDS youth, including the Pacific Island Students Fighting Climate Change, have been pivotal in driving this global breakthrough however, the insufficient scientific publications on SIDS continue to highlight the need for increased collaboration, financial allocation, and greater prioritization of health-centred research.
Explore key findings of this year’s report
On the frontline of health impacts, spearheading the call for action
HEALTH HAZARDS, EXPOSURES, AND IMPACTS
A changing climate has profound implications for human health, with more frequent heat waves and extreme weather events, changing patterns of infectious disease transmission, deterioration of food and water resources, impacts on socioeconomic conditions, and the exacerbation of existing health challenges around the world. Indicators in this section track the multiple ways in which climate change threatens human health and wellbeing.
Indicator 1.1.1: Exposure of Vulnerable Populations to Heatwaves
Infants now face 7× more heatwave days (2.4 to 15.8 days per year per infant), and older adults 5× more (3.0 to 15.9 days per person per year) than the 2000–2009 baseline.
Indicator 1.1.3: Change in Labour Capacity
4.4 billion potential work hours were lost across SIDS in 2023, the highest single-year potential loss since tracking began in 1990.
Indicator 1.4.1: Food Insecurity and Undernutrition
In 2023, 11.7 million people in SIDS countries were malnourished and an additional 2.7 million people were estimated to have experienced moderate or severe food insecurity due to a higher frequency of heatwaves and droughts, compared with the 1981-2010 baseline.
ADAPTATION, PLANNING, AND RESILIENCE FOR HEALTH
With climate change increasingly threatening the health and wellbeing of populations in every country, actions to build resilience and adapt to climate change are urgently needed. This section tracks how communities, health systems, and governments are understanding the health risks of climate change, the strategies and resources they are deploying, and how adaptation and resilience measures are being implemented globally.
Indicator 2.1.1: National Assessments of Climate Change Impacts, Vulnerability, and Adaptation for Health
Only 25% of SIDS have completed national plans for adaptation and mitigation implementation, but few are strongly informing policy development.
Indicator 2.1.2: National Adaptation Plans for Health
Only 37% of participating SIDS states (10 of 27) have developed national health and climate change adaptation plans.
Indicator 2.3.1: Lethality of extreme weather events
The total number of deaths related to extreme weather events fell from 8,100 in 2000-2009 to 1,800 in 2025-2024 – a 22% decrease. The reduction in deaths may be due to the strengthening of resilience mechanisms, including improved surveillance and early warning systems.
MITIGATION ACTIONS AND HEALTH CO-BENEFITS
Reducing greenhouse gas emissions is essential to limit the health threats of climate change. Simultaneously, many of the interventions required to mitigate and adapt bring enormous benefits for human health and wellbeing in the form of cleaner air, healthier diets, and more liveable cities. Tackling climate change could be the greatest global health opportunity of the 21st century. Indicators in this section track the world’s efforts to mitigate climate change, and the effective and the health benefits of this response.
Indicator 3.1.1 Energy Use and Generation
Across SIDS, 18% of on-grid and 21% of off-grid electricity capacity came from renewable sources, up from 9% and 13 %, respectively, in 2000.
Indicator 3.2 Mortality From Ambient Air Pollution
In 2021, 26,000 deaths were attributable to PM2·5, a 5·7% increase compared with 24,000 deaths in 2016. The Pacific SIDS experienced an 18% increase in deaths across the same period, from 2,200 to 2,600, while the Caribbean had over 20,000 deaths in 2021, a 4·4% increase.
ECONOMICS AND FINANCE
The health impacts of climate change have profound economic implications. This section tracks the economic costs of the health impacts of climate change and its drivers, as well as the extent to which the world’s economy and financial systems are enabling the transition to a health-promoting, zero-carbon economy.
4.1.3 Loss of Earnings From Heat-Related Labour Capacity Reduction
Across all SIDS, potential lost wages in 2024 reached a record high of US$14·7 billion, increasing by 11·4% from 2023.
Indicator 4.2.1 Clean Energy Investment
Between 2000 and 2022, a total of US$4 billion of public funds was invested in renewable energy in SIDS. The difference in public investment in renewables and fossil fuels has remained at approximately US$300 million per year since 2020.
Indicator 4.2.2: Global Multilateral Funding for Health Adaptation Programmes
Overall, since 2017, NAP development in 24 SIDS has been supported via the GCF. This proves that global financial assistance in capacity building is a key pillar accelerating national readiness for sustainable health adaptation.
PUBLIC AND POLITICAL ENGAGEMENT
Public and political engagement underpins the foundations of the world’s collective response to climate change, with reductions in global emissions at the speed required by the Paris Agreement depending on engagement from all sectors of society. This working group tracks key actors’ engagement with the links between health and climate change, including in the media, national governments, the corporate sector, and the broader public.The indicators in this section track the links between health and climate change in the media, national governments, the corporate sector, and the broader public.
Indicator 5.1: Scientific Engagement on Health Impacts of Climate Change
There was a 216.7% increase in the number of scientific publications for SIDS from 2015 to 2024, with a closer examination of the trend in publications over the last five years (2020-2024) showed quite stable numbers, with an average of 93 (80-101) publications per year.
Indicator 5.2: Government Engagement in Health and Climate Change
Although mentions of the intersection of health and climate change are declining, the SIDS governments still recognise the overall issue, with 97% (36 out of 37) mentioning climate change and its impact on their countries. Sea level rise, coastal erosion, and extreme weather events, along with the lack of recovery funds, were prominent themes in the governments’ speeches.
Dr Georgiana Gordon-Strachan, Director of the Lancet Countdown SIDS Centre
“This report shows that protecting people from rising temperatures must now be a core priority for climate and health policy. We know what works—the challenge is ensuring that SIDS have the resources to implement solutions at the scale and speed that this crisis demands.”
Dr Roannie Ng Shiu, Working Group 1 Lead on Health Hazards, Exposures and Impacts
“SIDS have long led on climate action and justice; now the international community must respond with the finance and partnerships needed to turn that leadership into lasting resilience.”
Meet the SIDS report author team
Hailing from the Pacific, Caribbean, Indian Ocean, Europe, the Americas, Oceania, and Asia.
Country data sheets
Our country data sheets highlight the latest SIDS report findings at a country level.