Why climate change poses an ‘existential threat to humanity’: A conversation with Dr. Samantha Green
Climate change has been deemed the greatest health threat of the 21st century by both The World Health Organization and The Lancet, and examples are increasingly easy to find, from wildfires raging in California, to a devastating heat wave in British Columbia.
Ahead of Earth Day, we spoke with Dr. Samantha Green, Unity Health family physician and the Faculty Lead in climate change and health at the University of Toronto’s Department of Family and Community Medicine, about the numerous ways climate change affects our personal health, how healthcare providers and patients can tackle the problem, and why there are still reasons to be hopeful.
Q: To start, for those who are not aware, can you describe some of the ways climate change can impact health?
Dr. Green: The increase in global temperatures has led to an increase in extreme weather events, such as heat waves, storms, droughts, wildfires, and flooding. Extreme heat days are especially a health threat to people with chronic conditions, the elderly, and young children, as well as those most at risk of exposure, such as people experiencing homelessness and those without access to air conditioning. We saw what happened last year in B.C. with the unprecedented heat dome event that killed more than 700 people.
Toronto Public Health has estimated that in the early 2000s about 120 people died every year in Toronto from the heat, and we know that that number is increasing over time, with extreme heat days projected to double by 2040-2050. Extreme heat waves also set the conditions for an increase in wildfires, which exacerbate respiratory conditions, heart disease, and can even lead to poor diabetes control and poor pregnancy outcomes. Climate change has also led to more extreme storms and hurricanes, which can lead to flooding and water-borne diseases.
These extreme weather events can result in direct physical injury, and also displacement, as people flee their homes and communities to find safety. This is happening across the Global South, but also here in Canada. We saw this in Lytton, B.C., with the wildfires last summer – a whole community destroyed. And when people are displaced they experience an interruption in access to basic services, as well as poor mental health. Extreme weather is also affecting food security, as droughts decrease crop yields in Canada and around the world.
And while there is no known direct link between climate change and COVID-19, we know that climate change has resulted in the destruction of biodiversity and wildlife, which leads to humans having increased proximity to animals and other vectors of disease. Certainly climate change will be a driver of a future pandemic.
Q: The alarm bells have been ringing about climate change for years. Why do you think society has been generally slow to respond, especially when you compare it to how quickly we moved to address COVID-19?
Dr. Green: That’s a complex question and I think there are a few answers. One is that while the alarms have been ringing for years about climate change, they have not historically rung loudly enough. Part of that is a framing issue. Historically climate change has been framed as a polar bear problem and not a people problem, but it is clearly a people problem. It’s an existential threat to humanity, and we need to frame it that way. It is the number one health threat that we are experiencing, that we will experience in the coming decades, and we need to think about it that way and treat it that way.
Q: Are there lessons we’ve learned from COVID that can help us address climate change?
Dr. Green: It’s a good comparison, because we have seen throughout the COVID-19 pandemic that people are willing to make sacrifices to protect the health of their neighbours and communities. When people hear about climate change and the need to reduce emissions, I think they tend to tune out because it just seems impossible. They become hopeless.
But something hopeful from this pandemic is that we have seen how much our society is capable of changing. We need to completely eliminate the use of fossil fuels over the next couple of decades, if we want to hold the global temperature increase to 1.5 C above pre-industrial levels (a threshold set by the Intergovernmental Panel on Climate Change to avoid the most severe climate effects). That strikes me as very close to impossible, but we’ve seen what we are capable of when we’re determined.
It’s also crucial to build equity into any societal transformation as we address the climate emergency. This means protecting marginalized populations most affected by climate change and building a strong, robust just transition plan for affected workers, such as workers in the oil and gas sectors. Our government and taxpayers must ensure these workers have income support as we transition away from fossil fuels.
Q: What can healthcare providers and patients do if they want to help?
Dr. Green: Because of the scale of the problem I think the number one thing we can do is demand that our politicians take action, because this is not something individuals alone can solve. It’s something that we need to address as a collective, as a society. As elections come up, demand that your elected officials treat climate change like the emergency it is.
While individual action alone won’t be enough, there are things people can do that can be empowering and that are a good place to start. Data from Ontario show that some impactful ways you can make a difference are avoiding short-haul flights, taking public transit, walking or biking instead of driving, switch to an electrical heat pump for your home, and eating less beef.
As for healthcare, the biggest things hospitals, institutions and providers can do is to embed sustainability into our thinking and decision making. The Lancet ranks Canada among the most carbon-intensive health systems in the world. And the bulk of those emissions are not from healthcare buildings, but from medical products, medications and services.
Dr. Andrea MacNeill from UBC has produced a sustainable framework for healthcare providers, which has three components key to reducing healthcare’s carbon footprint. The first is health promotion and disease prevention, because if we prevent someone from having to use healthcare services, we’re reducing emissions. The second is the concept of choosing wisely—that is making sure every test and procedure that we undertake is necessary. The third is reviewing the carbon intensity of specific things, such as a hospital building or certain medications, and seeing if there are better alternatives. For example, metered-dose inhalers prescribed to patients with asthma have an outsized carbon footprint because they contain powerful gas propellants. There are alternative inhalers that can be prescribed to most patients that are less carbon-intensive.
Healthcare is responsible for about 4.6 per cent of emissions in Canada, which is roughly on par with the aviation sector. Reducing that number really means thinking about sustainability in every decision we make as healthcare providers- just as we consider patient safety, efficacy and cost.
By: Marlene Leung