Posted: 05 Oct. 2021 10 min. read

Climate change and health: What can hospitals do?

By Elizabeth Baca, M.D., M.P.A., specialist leader, Deloitte Consulting, LLP

More than 200 medical journals recently called climate change “the greatest threat” to global public health.1 Hospitals and health systems are uniquely positioned to reach populations that could face health issues related to a changing climate. These organizations could also have a positive impact on climate change by substantially reducing their typically large carbon footprints.

The impact of a changing climate is more apparent than ever. In August, Hurricane Ida ripped through Louisiana and left hundreds of thousands without power during a heat wave.2 A few days later, that same storm caused severe flooding in New York and New Jersey.3 In my home state of California, the Dixie Fire scorched nearly 1 million acres…and the fire season isn’t over.4 Some key rivers in the western US—which supply hydroelectric power and provide people, animals, and crops with water—reached historic lows.5 Even Hawaii faced wildfires and a severe drought.6 The United Nation’s scientist-led Intergovernmental Panel on Climate Change (IPCC) recently concluded we are currently at “code red” with respect to human-induced climate change.7

Extreme heat, combined with smoke and high pollen counts in the air, is exacerbating chronic health conditions such as asthma,8 and is leading to more cases of heat stroke and other illnesses. The changing climate is also increasing the risk of vector-borne diseases carried by mosquitos, ticks, and other insects.9 Lyme disease, which is spread by deer ticks, infects almost half a million people per year, according to the Centers for Disease Control and Prevention (CDC). Warmer and wetter weather could allow mosquitos to proliferate faster and infect humans with West Nile, Zika, and possibly even dengue. Climate change also has the potential to not only directly impact environmental factors, but also exacerbate social and economic factors that impact physical and mental health.

There appears to be growing pressure on hospitals, health systems, and other stakeholders to act and to create momentum for change, as I noted in my previous blog, taking action on climate change today could lead to a more resilient future of health tomorrow.

HHS turns to climate change

On August 30, the Department of Health and Human Services (HHS) announced that it had established an Office of Climate Change and Health Equity in response to President Biden’s Executive Order on tackling climate change at home and abroad. The Office’s mission is to protect vulnerable communities that disproportionately bear the brunt of pollution and climate-driven disasters (such as drought and wildfires) at the expense of public health, according to an HHS press release. Unfortunately, some of the groups disproportionately impacted by COVID-19 will likely be the same groups that struggle the most with the health effects of climate change.

Climate change is already on the radar of some large health companies such as pharmaceutical makers, consumer health product companies, medical device manufacturers, and the growing number of technology companies entering the health space. Many of these organizations have chief sustainability officers (CSO) in place. However, few hospitals and health systems have a CSO, which means the responsibility of addressing climate change is typically spread (and potentially diluted) across multiple titles—from the CEO to the chiefs of strategy, quality, finance, technology, operations, medical, nursing, and beyond.

Moving beyond traditional clinical data

Hospitals and health systems are well positioned to make a meaningful impact. Not only do they care for patients who suffer from climate-related illnesses, hospitals and health systems also contribute to the problem. If the US health care system were a separate country, it would be among the top 10 largest producers of carbon dioxide.10 I expect many hospitals and health systems (if they haven’t already) will soon start looking for ways to reduce their carbon footprint. A few years from now, having a climate-change strategy might be seen as table stakes, as is already the case in other industries.

As climate change becomes more obvious and dire, hospital and health-system leaders should look for ways to incorporate more robust environmental and climate data into their clinical operations to augment patient care interventions, ensure operational continuity, and inform medium-to-long term investments. Consider the following:

  • Climate-related health issues: Real-time weather and climate data are available through public sources and can help health systems predict and plan for near-term climate events (e.g., heat waves, dangerous air quality, severe storms). Care teams can use this data—along with information from public health departments—to proactively reach out to their communities and vulnerable patient populations. Hospitals might also use environmental and health data to determine when to deploy interventions with vulnerable patient populations to help mitigate the need for urgent or emergent care. Targeted calls and text messages, for example, could be used to warn patients to avoid outdoor activities. Asthma and cardiovascular patients could be urged to take steps to improve air filtration and ventilation in their homes. Data on the long-term climate trends (e.g., rainfall averages, flooding, floodplains) and the related population health impacts within relevant geographies can be critical to informing investments in services and infrastructure (see box).
  • Capacity and resource planning: Environmental and climate variables covering patient geographies should be incorporated into on-going short-term capacity and resource planning. These variables could help hospitals and health systems determine when to ramp up resources to accommodate increased demand for specific services (e.g., heat strokes, asthmatic episodes). For example, in June 2021, emergency departments in the Pacific Northwest saw an average of 102 heat-related illness per day—an increase of more than 600% from 2019.11 During periods of extreme heat, virtual health visits could help patients avoid exposure to poor air quality, as an example. In addition, understanding potential facility risks from climate events could help facilities directors prepare back-up generators in preparation for potential power outages.
  • Supply chain: Health systems should try to identify the geographies most critical to their supply chain—from pharmaceuticals to operating-room supplies—and integrate that information with related climate-trend data. This could provide insights into near-term and longer-term supply chain risks and help guide decisions around supplier relationships and procurement. So much of a health systems’ operations are dependent upon resources provided from distant geographies, and climate-resilience strategies should be guided by this understanding. Moreover, the ability to predict near-term supply chain risks can inform stockpiling and resource sharing across facilities/geographies or help determine when alternative supplier arrangements might be needed.
  • Medium-to-long term planning: In additional to near-term data, health systems should use climate-trends data to inform service and infrastructure planning and think about investments and infrastructure for interoperable data. Climate change is altering both the magnitude and the nature of health conditions in communities. An increased number of severe storms and flooding throughout the eastern half of the U.S., for example, could increase the risk of water-borne illness for vulnerable populations and cause more respiratory illnesses. Health systems should integrate climate-trends data with population health data to understand how health conditions might evolve in the years ahead. This understanding is critical to understanding the services and infrastructure that a patient population will likely require.

Data related to climate change is becoming more available and usable. I recently noticed that air-quality information is now a part of the weather information I pull up on my smartphone and is also integrated effortlessly into my home computer screen.

Climate week wrapped up at the end of September, and we are getting ready for the United Nations Climate Change Conference (COP26), which will be held in Glasgow, Scotland at the end of October. I’m encouraged that hospital leaders are beginning to discuss climate change and their carbon footprint. The next step should be for them to identify opportunities to incorporate environment-related factors into their clinical care pathways and operations to improve resilience and adapt to the health needs of a changing climate. I look forward to continuing this conversation with amazing leaders in a special session on Leadership for Sustainability, during the International Hospital Federation’s World Hospital Congress, which takes place in November.

Public sources of climate-related health data

Climate-related data is available through numerous public sources including the Centers for Disease Control and Prevention (CDC) and the Environmental Protection Agency (EPA).

Air quality data: The EPA’s Air Quality Index tracks local air quality and includes information about the five most common air pollutants and their health effects. The agency also tracts ozone, smoke, and fine, inhalable pollution, also known as Particulate Matter, which are 2.5 micrometers and smaller.12

Wildfire data: The US Forest Service’s Active Fire Mapping Program uses satellites to detect and monitor wildfires throughout the US.13

Pollen and mold data: The National Centers for Environmental Information is the world’s largest provider of weather and climate data. Among other things, it tracks data on pollen, mold, and drought.14

Infectious disease monitoring: The National Notifiable Diseases Surveillance System Patterns includes information about infectious diseases such as those spread by mosquitos.15


Michael Johnson, Jay Sekhon, EJ Kelley

1. Medical journals call climate change the ‘greatest threat to global public health, The New York Times, September 7, 2021

2. Hurricane Ida makes landfall in Louisiana, CNN, August 30, 2021

3. The storm warnings were dire. Why couldn’t New York be protected, The New York Times, September 10, 2021 

4. How the Dixie fire became the largest blaze of a devastating summer, The Washington Post, Sept. 14, 2021

5. Drought? This is what climate change looks like in the West, National Audubon Society, August 24, 2021

6. Pacific Islands wildfires highlight vulnerability to climate change and how to address it, The Hill, August 20, 2021

7. IPCC report: ‘Code red’ for human-driven global heating, warns UN chief, UN News, August 9, 2021

8. Asthma and Allergy Foundation of America, Climate and Health

9. Climate change fuels multiple threats to society’s health, Colorado School of Public Health, September 10, 2021

10. To be high performing, the US health system will need to adapt to climate change, The Commonwealth Fund, April 18, 2018

11. Heat-related emergency department visits during the Northwest heat wave, US June 2021, CDC, July 23

12. Air Quality Index, EPA, (

13. Active Fire Mapping program, US Department of Agriculture, Forest Service (

14. National Centers for Environmental Information, National Oceanic and Atmospheric Administration (

15. National Notifiable Diseases Surveillance System, CDC,

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