The health co-benefits of sustainable development

By Dr. Trevor Hancock20130525_092159

If, as I have argued in my previous column, unsustainable development is bad for health, then is the converse true? There is a strong case that in order to be healthy, communities need to be ecologically sustainable. Many of the actions that could be taken to make communities and societies more sustainable have what we call health co-benefits.

These health co-benefits are not limited to minimising the harm from global ecological change. There are large health costs to our current way of life, and thus large potential health benefits resulting from a shift to a more sustainable society. Here I will explore several examples that we identified in the Canadian Public Health Association’s Discussion Document on the ecological determinants of health; energy, agriculture and food, and urban design and transportation.

In a 2012 Global Energy Assessment, the direct global health impacts of energy systems (especially but not exclusively those that are fossil fuel-based) were likened in scale to “tobacco, alcohol, and high blood pressure, and exceeded only by malnutrition”. In fact, the authors estimated that they “directly cause as many as five million premature deaths annually and more than 5% of all ill health when measured as lost healthy life years”.

These health impacts arise largely from air pollution due to the combustion of fossil fuels, but there are also occupational health impacts (especially from coal mining), water and soil pollution, population displacement from dams, large numbers of deaths and injuries resulting from the use of energy in transportation and, of course, the health impacts resulting from climate change.

On the other hand, numerous studies have found that renewables (mainly wind and solar) and conservation have much smaller health and environmental impacts. Clearly, there are significant health benefits to be gained from a move away from fossil fuel-based energy, especially coal, with conservation and renewable energy systems offering a much healthier future.

This is not pie in the sky: A recent report by a group of independent Canadian scholars states that “Because renewable energy resources are plentiful, we believe that Canada could reach 100% reliance on low carbon electricity by 2035. This makes it possible, in turn, to adopt a long-term target of at least 80% reduction in emissions by the middle of the century”. The health benefits would be significant.

When it comes to food and agriculture, our current intensive system is an environmentally harmful approach that provides a highly processed diet low in fiber and high in animal protein. If we are to dramatically increase global food production to meet growing populations and demands, and simultaneously reduce environmental harm, we need a very different agricultural system and a very different diet.

In fact, one of the key strategies proposed by Jonathan Foley in a 2011 paper in Scientific American is a shift to a low-meat diet. Many more people could be fed on less land, thus reducing intensity. There are important health benefits to such an approach. Land, soil, water and biodiversity would be conserved and greenhouse gas emissions would drop. A reduction in portion size would reduce the pressure on the environment, not to mention our waistlines, while a shift to a low-meat or vegetarian diet would have a number of direct health benefits, including reduced rates of cardiovascular disease, diabetes and cancer.

Moreover, recent research in the UK has shown that a low-meat or vegetarian diet would markedly reduce greenhouse gas emissions. For high meat-eaters (more than 100 grams per day) those emissions are more than 7 kg of carbon dioxide equivalents per day, while for low-meat–eaters (less than than 50 grams per day) it is less than 5 kg per day, and less than 4 kgs per day for fish-eaters and vegetarians.

Finally, not only is urban sprawl a very energy-inefficient urban form, often requiring use of a car for many of the daily activities of life, it is also unhealthy. Conversely, the health benefits of ‘Smart Growth’ (one of the key urban development solutions to urban sprawl, which encourages active transport and public transit), has been likened to a ‘medical miracle’. It reduces deaths and illness from pollution, physical inactivity and traffic crashes, while promoting mental health and social capital.

In short, a more environmentally sustainable way of life brings with it many health benefits, including mental and social health benefits that are often overlooked. What’s not to like about that?

© Trevor Hancock, 2015

Originally published in Times Colonist 5 August, 2015