How Climate Change Impacts Global Health & Why It Is Our Greatest Threat

Climate change is and will be known throughout history as the most critical issue of our time. What we do now and over the course of the next decade will forever impact the lives of those to come long after we are gone.

But while climate change remains an issue that is addressed under the lens of environmental science, it quickly (and not so quietly) has become the greatest threat to global health, making it our most pressing public health issue today.

According to the United Nations climate change report published in October 2018, it is possible to limit global warming to 1.5ºC (with 2ºC being what is considered the threshold for catastrophic warming), but it will require rapid and all-encompassing change throughout all aspects of society.

However, if this change can be implemented the benefits are clear for the health of our natural ecosystems, which directly ensure a more sustainable and prosperous future for humanity, and a more likely chance of us actually being able to achieve the UN Sustainable Development Goals by 2030.

For an interactive map showing our global warming trends check out this great resource from NASA.

How Climate Change Impacts Global Health & Why It Is Our Greatest Threat

Why Is Global Health So Important

What does global health mean to you? Does it look like a world without hunger and poverty? Does it mean access to clean water and safe spaces?

Global health encompasses all of these topics and so many more, but most importantly global health refers to the health equity, security, and prosperity of every single person, culture, and country on this planet.

Global health isn’t just an international topic, but also a domestic one, which is why it is so essential that all people view global health as something they are directly a part of — not something that they are watching from afar.

As the world becomes more globalized, from our food, to travel, to economies, it is no longer appropriate to think about health in the silos we used to in the past. Instead we must address health in a global context. With new infectious diseases now appearing in places they weren’t before it has become increasingly more apparent that global health threats anywhere in the world can quickly become an issue at home.

How Climate Change Impacts Global Health & Why It Is Our Greatest Threat

How Is Global health Being Directly Impacted By Climate Change

One of the issues I personally see as a public health professional is that we are still discussing climate change as an environmental issue and not a public health issue.

While yes, climate change may have in the past been an issue that fell solely within the realm of environmental and climate science, we have already begun to witness how the impacts of climate change are affecting the health of both people and planet.

More importantly — in order to make the impact we need to limit global warming to 1.5ºC we need more motivated global citizens, more corporations, more governments choosing to make climate progressive change a priority.

Health is one of those areas that can motivate that change, where environmental science can at times feel too abstract or confusing to allow for everyday (non-science) folks to grasp just how climate change really will affect them personally.

But once you start to talk about health, people begin to tune in, and all of a sudden the conversation about climate change went from being a big-picture science topic to one that directly impacts families in every home around the world.

How Climate Change Impacts Global Health & Why It Is Our Greatest Threat


Water is one of our most precious natural resources that is an essential part of our health. While having such convenient access to water with the turn of a faucet makes water something that seems abundant, for many living in water scarce regions around the world water is a precious resource that is not guaranteed, or taken for granted.

Over the course of the twenty-first century, climate change is projected to reduce available renewable surface and groundwater resources significantly. Not only will this add to the already 844 million people who currently live without access to clean water, it will increase competition around water and impact security related issues and conflicts that arise due to water scarcity.

How Climate Change Impacts Global Health & Why It Is Our Greatest Threat

air quality

Air quality is essential for optimal health, and is already being impacted by climate change. According to the NRDC the health of nearly 127 million Americans is threatened by smog pollution and increased ragweed pollen, which can significantly impact those living with asthma and respiratory allergies.

Smog pollution is a direct result of pollution from industrial power plants, motor vehicles and other emission producing sources that combine to form something called “ground level ozone”. As temperatures and carbon dioxide levels rise, smog increases as well as the growth of pollen producing plants like ragweed, a common allergen.

Increased smog and pollen contribute to more “bad air days”, which result in an increase in hospital visits, missed days at school for kids, and even in the worst cases, death. While air quality may be something that many take for granted, if you or a family member suffers from asthma or respiratory allergies you know just how important air quality is for our health.

How Climate Change Impacts Global Health & Why It Is Our Greatest Threat

Food Security

One of the sustainable development goals is to eradicate hunger by 2030, yet this will not be possible without ensuring that our food supply is capable of providing enough nutrients to feed the every growing global population. Much of this food security relies on how we are able to combat climate change, as one of the areas which will be most impacted by climate change is our global food system.

While many technological advancements have been made to combat variables in agriculture, from improved and more efficient machinery to irrigation, weather patterns still remain to be the most important factors impacting crop yield, diversity, and security.

Over the past decade we have also begun to see a collapse in global bee colonies, which has also been linked to climate related changes, and is directly impacting our global food security and diversity. With more than 1/3 of our food supply relying on our pollinator friends, it is clear that if the bees are in danger from climate related change — so is our food supply.


Climate change will disproportionately impact populations around the world with the most significant being Sub-Saharan Africa, South Asia, and Latin America—also known as the global “hot spots”. While climate migration can be difficult to categorize, since 2008 an average of 24 million people have been displaced due to weather related disaster, and the World Bank estimates that another 143 million people could be displaced by climate related issues such as desert expansion and rising sea levels by 2050.

Climate related migration will also impact the way in which disease is spread and capable of being contained as mass populations of people are forced to migrate to more habitable parts of the world.

increased spread of disease

Mass migration is not the only cause of concern when it comes to the increased spread of disease, a warming planet creates more mosquito friendly climates, which is anticipated to increase the rates of infection of mosquito borne diseases like malaria, West nile virus, zika, and dengue fever.

Areas of the world, like the southern United States of America, that at one point were not affected by these diseases will begin to see an uptick in cases.

Clearly climate change is much more than an environmental issue and is already impacting the lives and global health of every human on this planet. The question is — what are we going to do about it?