By Abbas Nazil
At COP30 in Belém, Brazilian researcher and Fiocruz environmental health specialist Sandra de Souza Hacon warned that climate negotiations continue to ignore the deep and long-standing connections between environment and human health.
Hacon, who has spent two decades studying how climate change, deforestation and social inequality shape the spread of viruses and other biological threats, said the climate crisis cannot be understood—or addressed—without integrating ecological and health perspectives.
She explained that deforestation, hydrological cycle disruption, biodiversity loss and pollution in the Amazon have intensified environmental degradation and created ideal conditions for viruses to circulate and mutate.
Hacon noted that despite the growing scientific evidence, health remains marginal in climate discussions, pointing out that even the Intergovernmental Panel on Climate Change only began seriously addressing health in its 2007 report.
She highlighted that indigenous peoples, forest communities and traditional populations have long understood the interdependence between ecosystems and health, yet global policy still treats them as separate spheres.
Recent outbreaks such as Oropouche fever and dengue illustrate how temperature increases, extreme weather and land-use changes accelerate vector spread and disease transmission.
She emphasized that Brazil now faces rising cases of dengue and chikungunya, with climate instability enabling viruses, fungi and bacteria to move faster across regions.
According to Hacon, health systems—both in Brazil and globally—remain reactive, underprepared and poorly integrated with climate modeling, early warning systems and environmental surveillance.
She argued that prevention remains weak, even though technology, knowledge and institutional capacity already exist to act earlier.
Examples such as Fiocruz’s community monitoring app, which helped prevent a yellow fever outbreak, show the potential of proactive surveillance, especially in remote and forested areas.
Hacon said newly contacted indigenous populations require urgent monitoring to prevent climate-driven pathogens from causing devastating impacts in vulnerable communities.
Despite Brazil’s scientific strength, she warned that political will and resource allocation remain insufficient, leaving the country “in a holding pattern” rather than leading regional climate-health responses.
She pointed out that even at COP30, health was sidelined, despite participants experiencing heat stress, dehydration and discomfort caused by extreme temperature and humidity—clear evidence of climate impacts on well-being.
Hacon concluded that the climate, environment and health nexus is visible everywhere yet remains institutionally overlooked, and she urged global leaders to place environmental health at the center of climate action.
