Two Canadian health systems innovators are getting creative to tackle greenhouse gas emissions.

By Sabeen Abbas   •   May 20, 2026

SciComm News

Imagine you have a loved one being cared for at your local hospital. When you arrive to visit them, you notice several things: Trees and green spaces around the hospital building provide shade and support biodiversity. The parking lot has electric vehicle chargers and bike stations. Inside the hospital, water refill stations are readily available. Items that can safely be reused, such as linens and gowns, are being chosen over disposables.

These are a few examples of what a “green healthcare facility” could look like in practice. Making changes, like these, is essential if Canada is going to meet its commitments as part of the global response to climate change and reduce greenhouse gas (GHG) emissions. Currently, the Canadian healthcare system accounts for 4.6 per cent of Canada’s national GHG emissions. In comparison, the aviation industry contributes between 2 and 5 per cent of the world’s GHG emissions.

(Photo by Renata Rafa via Pexels)

Reducing these GHG emissions in the Canadian healthcare system is something two scientists at McMaster University are actively trying to achieve. Dr. Sujane Kandasamy, an Assistant Professor of Medicine and Dr. Myles Sergeant, Assistant Clinical Professor of Medicine, are co-founders of PEACH (Partnerships for Environmental Action by Communities within Healthcare) Health Ontario.

PEACH Health Ontario is supported by a network of clinicians and administrators seeking to promote climate action in the healthcare sector. The goal of PEACH Health Ontario is to share information, ideas and resources and to collaborate on projects that support climate action in the health care sector.

The PEACH tree

One of the tools created by PEACH Health Ontario is the PEACH tree, a graphic aimed at clinicians, healthcare administrators and leadership and shows the impact of these different GHG emission reducing actions. These actions can have a small, medium or large effect on the reduction of GHG emissions. The location of the fruit on the tree also shows whether an action will require an initial investment or result in immediate savings (within a year). For example, some “low-hanging fruit,” such as taking a patient off unnecessary medications - also known as deprescribing - results in immediate savings and a large reduction of GHG emissions.

PEACH Health Ontario Co-Leads, Myles Sergeant, PhD and Sujane Kandasamy, PhD.

The power of this tool is in the way that visuals are used to convey information. This PEACH tree tool was created by analyzing the existing research on the GHG emissions produced by certain healthcare practices. Dr. Kandasamy and Dr. Sergeant also approached their colleagues to get a better sense of what sorts of practices could make impactful changes.

“I think people are looking for those kinds of resources [that answer the question of] ‘what can I do that's going to be impactful?’...‘If I could do one or two things, what would those be?’” said Dr. Kandasamy. “People don't have time to calculate those things on their own. So, it was an effort to do some of that work, so that it could be easier for people to see what actions could have big impact.”

The "PEACH tree" which visualizes data to help move knowledge about sustainable practices into action. (Sergeant, Myles, et al. “Identifying Opportunities for Greenhouse Gas Reductions and Cost Savings in Hospitals: A Knowledge Translation Tree.” Healthcare Quarterly, vol. 25, no. 3, 25 Oct. 2022.) Photo republished with permission of Myles Sergeant, PhD.

Dr. Sergeant notes misconceptions that people might have where some initiatives that have an upfront cost might actually bring about greater savings in the long run. He points to the hiring of staff whose job would be to develop and lead these changes.

“For example, an energy manager’s $100,000 salary, so way up there on the tree, but in actual fact, that energy manager is going to save you $100,000 in less than one year. That’s a pretty fast return on investment,” Dr. Sergeant said.

PEACH Health Ontario has worked on several projects to support a sustainable healthcare system. The original PEACH tree has led to other iterations targeted to specific audiences, such as the low-carbon fruit tree for primary care. A PEACH tree specific to surgeons and another for internal medicine is also in the works. A French version of the PEACH tree is also available on their website.

Making an Impact

PEACH Health Ontario’s work is doing more than just highlighting opportunities to reduce GHG emissions. In 2024, Newfoundland and Labrador implemented a province-wide ban on the purchase of desflurane gas in favour of other anaesthetic gases exist that have a much lower carbon footprint. Desflurane gas is used during anesthetic procedures and has the same carbon footprint as driving a car for 320 km. The Northwest Territories also announced a province-wide ban in January 2025.

While there are many factors that ultimately led to these decisions, Dr. Sergeant shared an anecdote that points to the PEACH tree providing the initial spark. While listening to a presentation at a conference, Dr. Sergeant unexpectedly encountered his own work. “A presenter from Newfoundland shows our PEACH tree,” he said. “Then the next slide she shows the PEACH tree again with a circle around desflurane gas. And then she said, ‘[Dr. Sergeant] spoke to us two years ago. And we decided to ban desflurane gas in Newfoundland.’”

Myles Sergeant, PhD, and Sujane Kandasamy, PhD, presenting their work on sustainable healthcare practices. 

Although there are many steps which lead to actionable change, like the banning of desflurane gas, tools like the PEACH tree point to the opportunities which can potentially make the greatest impact to reduce GHG emissions.

On the importance of taking action, Dr. Kundasamy notes that anyone can make a change, you don’t need to be a climate scientist.

“I think it's one of those fields where you don't need to know everything under the sun and all the evidence to make some changes,” she says. “And if we can guide people on what some of those changes could be, I think that's very helpful.”

Upcoming PEACH Health Ontario Conference

On Thursday, May 21st, PEACH Health Ontario will be hosting their annual conference, titled, Stories for Health Systems Change: Mobilizing Climate Justice Narratives, at the David Braley Health Science Centre in Hamilton, Ontario. Using narrative and arts-based approaches, and including a diversity of perspectives from community members, climate change experts, health and social service providers, researchers, policy-makers and artists, the conference will explore the human experiences of climate change in healthcare among other related topics. More details can be found on the conference website.

About the Author

Sabeen Abbas completed her MSc in Public Health Sciences from the University of Waterloo. She has a background in biology, professional writing, and education.