S20 warns that climate change is endangering human health, food systems and ecosystems worldwide
Urgent, science-driven action is needed to protect the well-being of people, ecosystems and the planet from the worsening impacts of climate change.
This call comes from Science20 (S20) — the G20’s official science and technology engagement group formed by national science academies to represent the global scientific community — in its 2025 statement on climate change and well-being, released by S20 South Africa.
“Climate change remains one of the most urgent challenges of our time, with far-reaching
consequences for human and planetary well-being,” the S20 said. “It threatens health, livelihoods, and the stability of Earth’s life-support systems — especially for people in vulnerable situations.”
Endorsers of the statement include the Academy of Science of South Africa, the United States, National Academy of Sciences, the Russian Academy of Sciences, the Indian National Science Academy and the Brazilian Academy of Sciences.
The statement notes that since the industrial era, human activities have been the primary driver of climate change, far outweighing natural phenomena such as solar variations, volcanic activity, ocean circulation patterns, and natural greenhouse gas emissions.
Highlighting that 2024 was the warmest year on record, the S20 emphasised the need for urgent, evidence-based mitigation (to reduce climate change) and adaptation (to address its impacts).
This is not only to reduce risk but to seize opportunities for innovation and co-benefits for health, ecosystems and the economy.
Aligned with South Africa’s G20 theme of solidarity, equality and sustainability, the S20 outlined five priority areas for action.
Human and environmental health
“Climate change negatively impacts human well-being, oceans and air and water quality and reduces biodiversity,” the S20 said, warning that more frequent heatwaves, storms, floods, droughts, and wildfires are eroding ecosystem resilience.
These impacts contribute to the displacement of people and communities, increasing food and nutrition insecurity and posing a heightened risk for disease, especially infectious diseases.
The S20 recommends addressing the interconnected health of humans, animals, and ecosystems alongside climate, food and water security, energy, biodiversity and pollution.
Suggested measures include strengthening air and water quality monitoring, regulatory systems and clean technology adoption; enhancing early warning and response capacity; and improving disaster management, with a focus on vulnerable groups and ecosystem services.
Food, water and energy nexus
Climate change disrupts the interconnected systems that sustain the food, water and energy, intensifying extreme weather, land degradation and ocean changes.
“With increasing demands for resources due to population growth and aspiration for
improved living standards, safeguarding this nexus requires integrated, climate-resilient policies, resource-efficient technologies and sustainable consumption patterns.”
Recommendations include promoting water-efficient, climate-smart and agroecological agriculture; strengthening local food systems; supporting small-scale producers; and advancing compact, low-emission urban design that integrates renewable energy and sustainable water use.
Indigenous peoples, local communities and vulnerable groups
Indigenous knowledge, practices and values are increasingly recognised as vital in addressing climate impacts. Yet these communities often face disproportionate risks because of their dependence on threatened ecosystems and limited resources.
The S20 calls for inclusive participation of indigenous peoples and local communities in decision-making, support for community-led adaptation and accessible early warning systems for vulnerable populations.
Climate adaptation
Despite progress, current adaptation efforts remain insufficient. Effective adaptation across multiple scenarios is essential, particularly for communities in climate hotspots.
The S20 proposes strengthening infrastructure and local capacity, improving access to region-specific climate data, and restoring and protecting ecosystems to enhance adaptation and biodiversity.
Climate mitigation
Sustained efforts are needed to reduce emissions to net zero. This includes transitioning away from high-emission activities, embracing renewable and low-emission energy technologies, scaling up carbon reduction and removal, improving efficiency, managing waste and investing in nature-based and circular solutions.
Low-emission and circular-economy solutions must be accelerated, and geoengineering — using large-scale technologies to cool the planet — should be explored under robust governance. Enhanced mitigation will reduce climate risks, lower adaptation costs, and increase resilience.
The statement concludes that addressing climate change is a societal imperative.
“By acting decisively across these five priority areas, we can improve public health, advance social equity, strengthen food and water security, and drive sustainable innovation.
While climate change presents serious challenges, the research and innovation it has inspired offer pathways to a more sustainable and economically dynamic future.
The S20 said that with global cooperation, inclusivity and science at the core, “these challenges can become a catalyst for shared well-being and lasting prosperity.”