In many parts of the world, long weekends are planned months in advance. Flights are booked, cabins reserved, routes mapped. Families coordinate schedules and look forward to a brief pause from everyday routines. And then, sometimes at the very last minute, the weather intervenes.
A heatwave cancels outdoor plans. Wildfire smoke grounds flights. Flooding closes highways. A hurricane shifts course. In other cases, it’s the opposite — a late-season snowstorm shuts down airports, buries roads, and leaves everyone asking how this fits into a “warming planet.” What was meant to be a brief escape turns into a scramble to reroute, reschedule, or simply stay home.
For most of us, this registers as an inconvenience. A ruined vacation. A wasted reservation. An unexpected expense. We may grumble, post a photo of grey skies or flight delays, and move on.
If you are reading this article at any point in time — whether this year or should time travel become a thing—from the future (and hopefully still on Planet Earth), chances are your family has experienced at least one such disruption. These moments have become common enough that they barely register as unusual.
They also tend to spark a familiar question: If the planet is warming, why is it still snowing?
But pause for a moment and widen the lens and this is where the distinction between weather, climate change, and global warming matters. Weather describes short-term events—a snowstorm, a heatwave, a heavy rain. Climate change refers to long-term shifts in patterns, intensity, and variability. Global warming refers specifically to the long-term increase in average global temperatures, which can destabilize atmospheric systems and, paradoxically, lead to more extreme cold events in some regions.
Organizations such as the World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC), and the United Nations have consistently emphasized this distinction. Climate change does not eliminate cold or snow; it makes weather more unpredictable, more intense, and more disruptive.
And while these disruptions may feel minor in our daily lives, they are often the first visible signals of a much larger system under stress — one with implications that extend far beyond a single long weekend.
From Inconvenience to Catastrophe
Climate change does not affect everyone equally. The storm that cancels a beach trip in one country may erase an entire community in another. The heatwave that keeps a city indoors for a few days may prove fatal elsewhere.
In many developing and underdeveloped regions, climate-related events are not temporary disruptions — they are existential threats. Floods contaminate drinking water and spread disease. Droughts collapse food systems and livelihoods. Extreme heat overwhelms already fragile health infrastructure, leaving hospitals understaffed, underpowered, or inaccessible when they are needed most.
Recovery in these contexts is rarely quick. It is often slow, incomplete, or impossible. What appears elsewhere as a short-term inconvenience becomes, for millions of people, a long-term health crisis.
This disparity is central to understanding climate change as a health issue, not just an environmental one. Health risks multiply where systems are weakest, resources are scarce, and safety nets are thin. Climate shocks interact with poverty, inequality, and limited access to care, amplifying their impacts on physical and mental health.
Importantly, these outcomes are not hypothetical. They are already unfolding. Rising temperatures are increasing heat-related illness and mortality. Changing precipitation patterns are driving food and water insecurity. Shifts in ecosystems are expanding the range of infectious diseases. Healthcare systems — particularly in vulnerable regions — are being stretched beyond capacity.
It is in this context that global health institutions increasingly describe climate change not as a future concern, but as an ongoing humanitarian and public health emergency — one that threatens to reverse decades of progress in global health and development if left unaddressed.
Climate Change as a Global Health Emergency: What Institutions Are Saying
Climate change is no longer framed by leading institutions as a distant environmental concern. It is increasingly understood as a global health emergency—one that threatens lives, strains health systems, and undermines decades of progress in public health and development.
This shift is evident in how major organizations approach climate change today.
World Health Organization (WHO): Climate Change as a Threat Multiplier
The World Health Organization has been unequivocal: climate change is one of the greatest health threats facing humanity. WHO describes it as a “threat multiplier”—one that intensifies existing health challenges while creating new ones.
According to WHO:
- 3.6 billion people already live in regions highly vulnerable to climate change
- Between 2030 and 2050, climate change is expected to cause approximately 250,000 additional deaths per year from heat stress, undernutrition, malaria, and diarrheal disease alone
- Regions with weak health infrastructure, largely in developing countries, are least able to cope without significant external support
WHO also emphasizes that climate action is a health opportunity. Reducing greenhouse gas emissions—particularly through cleaner energy, better transport, and improved food systems—can deliver immediate health benefits, most notably through improved air quality and reduced pollution-related disease.
Centers for Disease Control and Prevention (CDC): A Public Health Lens
In the United States, the CDC frames climate change as a growing public health stressor that amplifies existing risks and introduces new ones.
The CDC identifies climate-sensitive health risks including:
- Increased respiratory and cardiovascular disease linked to air pollution
- Injuries, illness, and premature deaths associated with extreme heat and weather events
- Shifts in food-, water-, and vector-borne diseases
- Mental health impacts, including stress, anxiety, trauma, and displacement
Importantly, the CDC highlights that vulnerability is not uniform. Age, income, geographic location, housing quality, and access to healthcare all influence who is most at risk—reinforcing that climate change is as much a social and equity issue as it is a physical one.
World Bank: Health, Climate, and Economic Stability
The World Bank approaches climate change through the interconnected lenses of health, poverty, and economic resilience. It has described climate change as a global health emergency with consequences of historic scale.
Key findings include:
- Climate change could result in at least US$21 trillion in excess health-related costs in low- and middle-income countries by 2050
- Without action, climate impacts could push 132 million people into extreme poverty by 2030, with more than half of that increase driven by health-related factors
The World Bank also notes a critical feedback loop: while health systems are highly vulnerable to climate change, the health sector itself contributes approximately 5% of global greenhouse gas emissions, underscoring the importance of decarbonizing healthcare infrastructure alongside strengthening resilience.
How Climate Change Impacts Health
Taken together, the perspectives of WHO, CDC, and the World Bank point to a shared conclusion: climate change affects health through multiple, interconnected pathways. Some risks intensify, others emerge, and none are evenly distributed.
As illustrated in the climate–health framework above, climate change influences health both directly and indirectly, shaped by exposure, vulnerability, and system capacity.
Key pathways include:
- Air pollution
- Increased exposure to fine particulate matter and ozone
- Higher rates of asthma, cardiovascular disease, and respiratory illness
- Temperature extremes
- Heat-related illness, heat stroke, and increased mortality
- Disproportionate impacts on older adults, children, outdoor workers, and pregnant individuals
- Precipitation extremes
- Flooding and drought that disrupt water quality and sanitation
- Increased risk of waterborne disease
- Food security and nutrition
- Reduced food availability, quality, and diversity
- Increased undernutrition and foodborne illness
- Vector-borne diseases
- Expansion of mosquitoes, ticks, and other vectors
- Increased transmission of diseases such as malaria and Lyme disease
- Mental health and psychosocial impacts
- Anxiety, trauma, and stress related to displacement, loss, and uncertainty
- Long-term mental health consequences following climate disasters
These impacts are mediated by social, economic, and environmental determinants—meaning that communities already facing inequities experience the greatest harm.
Figure: Overview of climate-sensitive health risks, including exposure pathways and vulnerability factors. Climate change affects human health both directly and indirectly, with impacts strongly influenced by environmental, social, and public health determinants.
Source: U.S. Centers for Disease Control and Prevention (CDC).
Why this framing matters
When climate change is understood primarily as an environmental issue, responsibility feels distant and abstract. When it is understood as a health emergency, the implications become immediate, personal, and ethical.
It was against this growing recognition—during a moment when global health systems were already under extraordinary strain—that I hosted a conversation on climate change and health in 2020. That discussion, and what followed, helped crystallize why health must sit at the center of climate action.
When Climate Change Becomes Personal: A Health Perspective
Reflections on why climate change is, and will remain, a human health issue
This article is written in early 2026, reflecting on a conversation hosted several years earlier. If you are reading this in 2035 or 2040, the science discussed here may have evolved. However, the central premise has not changed: climate change is not only an environmental or technical challenge. It is fundamentally a human health issue. That reality has only become more evident with time.
Why this conversation still matters
In late 2020, as much of the world was emerging from the acute phase of the COVID-19 pandemic, I moderated a webinar on Climate Change and Health. The speakers were Dr. Joan Schiller, a medical oncologist, and her son, Craig Schiller, a climate and green building professional.
At the time, climate change was already well understood scientifically, yet it was still often discussed in abstract terms—emissions curves, temperature thresholds, and distant future impacts. Framing climate change through the lens of human health made the issue immediate, personal, and difficult to ignore.
Since then, extreme heat events, wildfire smoke, air quality alerts, healthcare system strain, and climate-driven displacement have become more visible and more frequent. What felt like an emerging perspective in 2021 now feels unavoidable. That is why this conversation—and the insights that emerged from it—remain deeply relevant today.
Why I hosted this discussion in the first place
During the pandemic, GBRI hosted numerous webinars addressing sustainability, resilience, and post-COVID strategies. This particular session was not initially intended to launch a broader initiative. It was simply an attempt to explore climate change from a different angle—one rooted in lived experience and human vulnerability.
Inviting a physician into a climate discussion was intentional. We wanted to move beyond technical metrics and ask a more fundamental question:
What does climate change actually mean for human health—across a lifetime?
The response to that question exceeded expectations. The conversation resonated not only because of the science, but because it connected climate change to things people care about deeply: family, community, safety, and well-being.
