On September 21, 2014, hundreds of thousands gathered in New York City, and in various locales around the world, to march together in a peaceful demonstration for climate justice. On September 23, 2014, politicians, celebrities, and corporate moguls alike convened at the United Nations headquarters to discuss preliminary strategy for addressing the causes and effects of climate change on local, national, and international scales.

As demonstrated by these impressive showings in recent weeks, it is clear that the issue of climate change is fast expanding past the boundaries that once framed it as merely “an environmentalist’s problem.” Growing awareness of the many different threats posed by climate change has drawn into the movement a range of political and social actors who, in the past, have not explicitly been associated with climate concerns. Society is quickly realizing that—in the words of UN Secretary General Ban Ki-moo—“the human, environmental and financial cost[s] of climate change…[are] becoming unbearable.”

The potential impacts of climate change upon human health, for example, have generated significant public concern despite being recognized by the media only recently. An increase in airborne pollutants—for example, ozone, automobile exhaust, aerosols from consumer products (e.g. hairspray), methane from agricultural operations, and carbon dioxide from the combustion of fossil fuels—may lead to an increase in the incidence of respiratory illness, especially among children, the elderly, and individuals with pre-existing illnesses. An increase in global temperatures will raise water temperatures accordingly, thereby providing a fertile breeding ground for bacteria and other pathogens that may lead to a rise in infectious disease rates. In addition, extreme weather events—flooding, droughts, heat waves, and hurricanes, for example—are expected to become much more frequent as temperatures rise, thus posing serious threats to the stability of the global food supply.

While the examples mentioned above constitute relatively direct outcomes of a shifting climate, climate change also has the potential to impart disastrous effects on health in a more indirect manner by exacerbating inequalities and vulnerabilities that already plague certain populations. In short, countries wracked with political upheaval, struggling economies, weak healthcare systems, and disproportionate resource distribution will suffer the health effects of climate change to a much greater extent than more financially- and politically-stable countries. Food security and accessibility, the lack of which is a primary driver of malnutrition, has become an important issue in this realm—according to Dr. John Ingram, a professor at the Environmental Change Institute at Oxford University, “weather has always affected food security, [but] particularly for many of the world’s poorest people.” In the summer of 2010, for example, several countries in Eastern Africa were hit with a severe, record-setting drought that caused prices of wheat, maize, and sorghum—three of the region’s staple crops—to skyrocket, thus depriving many of the regions’ inhabitants of food that was already in short supply. The medical infrastructures of the countries were insufficient to meet their dehydrated and malnourished populations’ needs, and the existence of armed conflict in nearby areas prevented relief organizations from reaching affected communities. What ultimately resulted was a food security crisis declared by many experts to be Africa’s worst in over twenty years. Estimates placed the number of people affected by the drought-induced crisis at 13 million, with approximately 100,000 deaths.

Ultimately, if we do nothing to prevent the advances of climate change, we can expect an increasing incidence of airborne diseases, an onslaught of waterborne bacterial pathogens, and an increasingly vulnerable food supply. We can expect disasters such as the severe African drought to become commonplace, and marginalized populations—usually the communities least responsible for climate change contributions—to suffer disproportionately from them. We will be setting up our children for a world in which “prevention” or “mitigation” no longer exist—a world in which “adaptation” is the only option available

While a complete reversal of climate change is, at this point, basically out of our reach, individuals can certainly take it upon themselves to adjust their behaviors and thus reduce their own contributions to the climate crisis.

The benefits of such a move to human health are twofold: on the one hand, adopting “greener” practices (e.g. biking to work, eating less meat) reduces the amount of carbon entering the atmosphere, potentially stemming the progression of a warming planet. On the other hand, many of these practices themselves promote the health of the individual (e.g. increased physical activity, adopting a diet less centralized around animal products and other intensively produced foods). Environmental health and public health are inextricably connected, yet the historical distinction between them has resulted in great polarization throughout society. A concern for the Earth is, ultimately, a concern global health and well-being.