When it comes to health, think big.

When you think of health, what comes to mind?

We live in a world where disease outbreaks dominate headlines and pharmaceutical commercials play during our favorite medical dramas, local news broadcasts, and game shows, so it’s easy to equate health with individual well-being. However, the definition of health can be a lot bigger than that, expanding to also reflect the health of our environment. This concept is now referred to as planetary health. 

How should we think about the health of a whole planet and why would we invest in it?

There are a lot of related terms for this most expansive view of health (figure 1) but the basic meaning and value proposition are straightforward. Planetary health acknowledges that our individual and societal health depend on the health of our environment, and that threats to our environment also threaten human health.

Figure 1

Public health is the science of preventing disease, prolonging life, and promoting health through the organized efforts and informed choices of organizations, communities, and individuals. Global health encompasses public health, but emphasizes transnational health determinants and solutions. One health integrates humans, animals, and ecosystems to underscore how the best health outcomes are achieved through a systemic approach. Planetary health focuses on how human activities impact the planet’s natural systems and human health.

An estimated 13 million annual deaths are attributed to avoidable environmental causes such as air pollution, extreme heat, unsafe drinking water, and food insecurity. Human activities also degrade planetary health by disrupting natural habitats and increasing the prevalence of zoonotic diseases and the likelihood of pandemics like COVID-19, which has led to over 7 million deaths globally to date. When you look holistically at these public health issues, the root causes are increasingly an unhealthy planet.

The link between environmental sustainability and health outcomes — now a hallmark of planetary health — builds on a foundation of public health, which brings a systems-level approach to health issues.

Expanding beyond traditional healthcare, which focuses on individual treatment, public health anchors to community health and disease prevention and evaluates how socioeconomic, environmental, and political factors impact individual health outcomes. In contrast to individual-focused healthcare, public health enables an interdisciplinary and humanistic study of people and health, which I am drawn to as someone whose interests span a variety of related subjects — biology, sociology, and social justice – and who is passionate about improving health outcomes for underserved communities.

Perhaps the best known example of a systematic approach for identifying a threat to human health is John Snow’s seminal work analyzing a cholera outbreak in London in the mid-1800s; this laid the foundation for public health practices and modern epidemiology. Snow meticulously mapped local water sources and disease cases throughout the city, eventually tracing the outbreak back to a water pump on Broad Street (figure 2).

By showing direct links between sewage-contaminated water and cholera, Snow’s work ultimately demonstrated that urban sanitation infrastructure is a key environmental determinant of health for people living in cities.

Figure 2

Investing in planetary health

The meticulous and systematic approach that Snow used to trace a cholera outbreak also informs our approach to planetary health investing.

Just as public health requires an evaluation of social and environmental conditions to understand how they impact human well-being, investing in planetary health requires a systematic review of factors that drive the market uptake of technologies that can benefit both human wellbeing and the environment. Our team focuses on the following impact metrics: 1) reducing emissions of pollutants, 2) increasing resource availability, and 3) restoring environmental quality. Let’s take those one at a time.

Reducing emissions of pollutants

Picture a congested highway or smoke coming out the top of an industrial plant; reducing carbon dioxide (CO₂) emissions from these sources is likely at the top of mind when you think of climate change.

Burning fossil fuels accounts for over 75% of global greenhouse gas emissions and also generates air pollution. Fine particulate matter released from fossil fuels, combined with the resultant ozone air pollution, leads to about 8 million deaths annually. Efforts to replace fossil fuels with renewable energy sources like solar or wind energy, transitioning to greater electrification, and increased energy efficiency could reduce CO₂ emissions by ~90%.

This shift to renewables and electrification would also substantially impact human health by reducing the risk of health problems linked to air pollution, including cardiovascular and respiratory disease, lung cancer, diabetes, stroke, low birth weight, and asthma.

Increase resource availability 

Over the last century the global population has grown by 4X, from 2 billion to 8 billion people, and is projected to peak at 10 billion by ~2060. This rapid population growth requires many changes in both productivity and distribution so that we can not only produce enough food, but also make sure it gets to the people who need it.

Although in aggregate the world already produces enough food to feed everyone, greater agricultural productivity can reduce the need to use marginal farmlands and allow more land to revert to nature. This, combined with more equitable and efficient food distribution, plays a crucial role in protecting communities from the threats of climate change. In 2022, 9.2% of the world’s population remained undernourished. Climate change increases global temperatures and the likelihood of extreme weather events, which in turn threaten crop production and food availability. The impacts of climate change are particularly prevalent in developing nations, and undermine the significant progress we have made in reducing global hunger. Poor distribution alongside higher food prices due to lower crop yields create further barriers to achieving food security globally.

Restore environmental quality 

We must also address the degradation caused by human activity by removing physical pollutants, restoring land, and reviving biodiversity, which all have mutual benefits for the planet’s and human health.

Restoring the environment is a critical piece of planetary health that can be driven by both consumer demand and public policy. Public awareness of climate change and the health benefits of living in greener, more walkable cities has boosted efforts toward sustainable urban planning. Increasing residential demand encourages city leaders to invest in public transportation infrastructure and green spaces. Green spaces are a particularly under-recognized component of climate-resilient urban environments with benefits to both the environment (reducing temperatures in urban areas, absorbing CO₂, helping increase biodiversity) and human health (decreased blood pressure, improved cognitive functioning, and better overall mental health).

Technological innovation helps drive advances in planetary health, but it can only go so far: public policy and regulations are crucial to properly incentivize companies to invest in climate solutions and actually adopt them. Up until the late 1900s, numerous industries and consumer products including paint, gasoline, and municipal pipes used lead extensively, which we now know leads to adverse neurodevelopmental effects and biodiversity loss. For reference, population blood lead levels (BLLs) between 1960 to 1980 were 3 – 5X higher than the levels currently considered acceptable. U.S. policies regulating these products, such as the Clean Air Act of 1970 and Toxic Substances Control Act of 1976, imposed legal requirements for lead-based product manufacturers and ultimately reduced average BLLs by ~94% between 1980 and 2016 (figure 3). 

Figure 3

A familiar public health challenge

If we could give our planet a check-up it would show no shortage of ailments, but by the same token it’s not the end of the world. A closer look shows that current threats to planetary health represent a public health challenge that is similar to others we have faced. They are serious. They are urgent. They are solvable. By prioritizing both planetary investment and healthcare innovation at RA Capital, we hope to mitigate the health impacts of environmental degradation while simultaneously fostering health and resiliency within our communities. Public health can show us how to do this in practice, using a systems-thinking approach and acknowledging interconnectedness between ourselves and the ecosystems that sustain us, preserving the health of humans and our planet together.