As drastically rising global temperatures threaten the health and wellbeing of populations, solutions that drive policy action must be based on scientific evidence of which strategies work in different scenarios.

The year of 2023 was the hottest on record. In July 2024, the world experienced the two hottest record-breaking days consecutively. Despite broad agreement that human-induced climate change is driving the rise in global temperatures, exacerbating the duration of heatwaves and increasing the frequency of natural disasters such as wildfires and tropical cyclones, the world remains unprepared, and 2.4 billion people from the most vulnerable regions and communities are at high risk from the deadly impacts of extreme heat.

Climate advocates have made progress to get policymakers to acknowledge some of the health impacts of climate change. During the 77th World Health Assembly, held from 27 May to 1 June 2024, World Health Organization Member States agreed on a climate change resolution committed to prioritizing health considerations in climate policy frameworks. But the translation from promise to action remains severely limited. Only 23% of the countries that signed the Paris Agreement on Climate Change assess the impact of climate policies on health and wellbeing, and less than 10% quantify the health co-benefits of climate mitigation plans. Health-specific climate action remains underfunded, with 2% of funding allocated to climate adaptation projects that directly aim to improve health. The Green Climate Fund, established as part of the UN Framework Convention on Climate Change to finance climate adaptation and resilience measures in low- and middle-income countries, allocates only 15% of the US $1.15 billion to implementing measures that specifically address health1, despite the fact that all of the countries probably need at least $11 billion per year to adequately address the health impacts of climate change.

Scientific research provides essential data for decision-makers to invest in and prioritize climate policies aimed at delivering effective, actionable and affordable measures that protect the health of communities. However, the current research landscape on climate and health is misaligned with those needs. There is substantial research on the health and mortality impacts of climate change, particularly from modeling and projections. But evidence is lacking on the feasibility, effectiveness and economic costs of climate adaptation and mitigation measures that protect health, or the positive and negative health consequences of current climate policies. Furthermore, climate research output is predominantly from high-income countries and China2. There is disproportionately limited research output from Latin America, sub-Saharan Africa and small island states that are experiencing the worst impact of climate change already, and there is a dire need to implement evidence-based measures to address the challenges that these regions face.

Climate and health research is also siloed within disciplines and academic circles, with fragmented engagement across sectors or partnerships between researchers and local policymakers, community, youth and indigenous groups. The consequences of this lack of multi-sector partnerships in supporting implementation are evident. For instance, the Great Green Wall project, an ambitious multinational reforestation initiative that aims to restore 250 million hectares of degraded land in the Sahara, is collapsing in part because of the lack of political engagement, resources and sustainable financing infrastructures in place for the initiative to succeed. Engaging with policymakers and communities most at risk in climate and health research would ensure that proposed intervention measures are supported by evidence showing that they are feasible, acceptable and sustainably integrated into communities, health systems and policies. Funding support for research investigating these climate measures is also crucial. The Wellcome Trust recently invested £17.5 million in the health co-benefits of community-based adaptation projects in vulnerable regions. This decision is an important first step that we hope other research funders will follow in investing in such initiatives.

Encouragingly, evidence that climate adaptation and mitigation interventions provide health returns is beginning to accumulate. Changes in housing designs to reduce indoor temperatures in rural settlements in the Gambia have been shown to decrease the risk of malaria3. Climate-friendly urban planning initiatives, including urban cable-cars in Bogota, Colombia, as sustainable transport systems, and green city projects that involve expanding tree canopies in Philadelphia, USA, are delivering benefits of improved health and wellbeing4. China’s Air Pollution Prevention and Control Action Plan, a national policy initiative established in 2013 to improve air quality and monitoring, resulted in substantial reductions in mortality attributed to air pollution within 5 years of its implementation5.

Climate and health research must now cross disciplines and involve policymakers and local communities to ensure that scientific evidence is incorporated into policies that directly impact health. We at Nature Medicine encourage submissions of research on the testing and implementation of climate adaptation and mitigation measures that provide benefits to health. Focusing on research into the health benefits of implementing such intervention measures will close evidence gaps that are preventing the development of effective health policies, and will inspire similar communities and regions to adopt workable solutions at scale.