The human condition and the health of our planet are inextricably linked. Our collective resilience, well-being, and ability to navigate crises are fully connected to the food we eat, the water we drink, the air we breathe, and, crucially, our relationship with the Earth. Yet, human influence has left no corner of our planet untouched. Currently, less than 25 percent of land area remains free from significant human impact, and this area is projected to shrink to less than 10 percent by 2050.

The latest figures from the Intergovernmental Panel on Climate Change (IPCC) and the UNEP Emissions Gap Report (2023) paint a bleak picture of the accelerating climate crisis. Record-breaking climate events surge in number, velocity, and scale, wreaking havoc across the globe with escalating frequency. Despite the Paris climate pledges, the current trajectory puts the world on track for a catastrophic temperature increase between 2.1°C and 3.9°C by 2100.

The world is edging ever closer to environmental changes that may be irreversible. Thawing permafrost, glacier loss, mass deforestation, the prevalence of microplastics in fauna, corals irreversibly bleached (triggering their death), and now the looming breakdown of the vast system of ocean currents signal an urgent need for action.

In recent decades, the Arctic has been warming much faster—four times faster, in fact—than the rest of the globe. This unprecedented warming has led to the thawing of vast permafrost areas, which scientists warn hold hidden dangers, including massive quantities of methane, a potent greenhouse gas. Permafrost degradation could also facilitate the transport of toxic waste and radioactive material into the environment, endangering ecosystem function and human health.

As the thawing and disappearance of permafrost accelerate, it raises concerns about the potential introduction of ancient microorganisms into the environment, with large uncertainties regarding their implications for modern ecosystems and human health. Novel antibiotic-resistant bacteria, viruses, fungi, and parasites could be released, posing significant challenges to human and animal immunity.

This phenomenon has already led to the revival of ancient mega-viruses and the emergence of an outbreak of anthrax in western Siberia from the rapid thawing of Bacillus anthracis spores in permafrost, killing thousands of reindeer and affecting dozens of people.

Zoonotic diseases are infectious diseases caused by pathogens that transfer to humans from non-human hosts. Changes in land use, deforestation and habitat destruction, urbanization, wildlife trafficking, and unsustainable agricultural practices are already considered activities increasing the risk of the emergence and spread of zoonotic disease.

Recent outbreaks, such as SARS, influenza A/H1N1, H5N1, MERS, Nipah virus disease, Ebola, and COVID-19, have resulted in substantial human and economic losses. The World Health Organization (WHO) reported 891 human cases of avian influenza (H5N1) from 24 countries resulting from contact with live or dead birds or contaminated environments (WHO 2024).

Antimicrobial resistance (AMR) refers to the ability of microorganisms such as bacteria, viruses, fungi, and parasites to resist the effects of antimicrobial drugs, making infections caused by these microorganisms more difficult to treat (UNEP 2023b). This resistance occurs when microorganisms evolve and adapt so the drugs designed to kill them become ineffective, thus rendering the medications ineffective.

AMR proliferation stems from increased antimicrobial use and misuse, alongside other microbial stressors like pollution, fostering resistance in both human and environmental settings, potentially surpassing other causes of mortality. Recognized by WHO as one of the top ten global health threats, AMR is already jeopardizing human and animal health, the environment, food security, economic development, and societal equity.

The Stockholm Convention on Persistent Organic Pollutants is an international treaty to regulate the release of toxic organic chemicals. Twenty-six chemicals have been banned globally, and nine compounds are under review. While it is noted that many of the chemicals registered for use may not make their way to the environment, many do. The volume of pollution and waste arising from processes that make and use these chemicals is projected to increase, as are the number of products with a variety of harmful chemical additives.

Many of these chemicals, including microplastics, find their way into the environment and the human body via agriculture, industry, transport, and domestic products. Some are associated with adverse health effects, but the number and nature of multiple exposures are not well understood, and the hidden health and ecological costs are likely underestimated.

The implications for the young are already of concern given placental and early childhood exposure and for those who are vulnerable and have pre-existing illnesses. The implications of an increase in chemicals being synthesized, the lack of environmental and human monitoring, and the complex mixtures to which ecosystems and humans are exposed make the task of characterizing impacts both challenging and crucial. There are many efforts and ongoing work to address these challenges.

The interconnectedness of human health and planetary well-being underscores the urgent need for comprehensive action to mitigate climate change, protect ecosystems, and reduce pollution. The health of our planet is a reflection of our own health, and safeguarding one inherently protects the other.