Cutting carbon dioxide emissions to fight climate change costs money. Lots of money: meeting the benchmarks set out in the Paris Agreement could require an investment equivalent to several percent of global gross domestic product by 2050. But what many politicians and policy makers are less aware of is that cutting emissions could also yield savings from improved health.
In fact, these knock-on benefits to health could cover a substantial portion of the cost of emissions-cutting efforts, according to a paper published October 27 in Environmental Research Letters.
In the new analysis, researchers reviewed 42 studies published over the last eight years that model the health benefits associated with lower carbon emissions. The studies include 24 related to air quality, 12 related to transportation, and six related to diet. In addition to quantifying these health benefits, about half of the studies also calculated the monetary savings that would come along with better health.
The air pollution studies looked at health improvements associated with cutting greenhouse gas emissions by specified amounts. Power plants, motor vehicles, and other sources of carbon dioxide emissions also produce other air pollutants that harm the lungs, especially particulate matter and ozone. In addition, these pollutants form more easily at higher temperatures. So cutting emissions and limiting warming tends to improve respiratory health and reduce hospital admissions for asthma as well as deaths from lung infections and lung cancer.
Most of the transportation studies asked what would happen if people drove less and walked, cycled, or took public transit instead. The biggest health risk associated with car use comes from physical inactivity. Therefore, driving less not only cuts greenhouse gas emissions but also reduces cardiovascular disease and overweight.
Finally, the diet studies asked how carbon emissions would change if people adopted diets with less red meat, more grains and pulses, and less processed food. (Red meat has the highest carbon footprint of any food, and eating too much red meat is also associated with cardiovascular disease and other chronic health conditions.) Overall, these studies show that changing our diets could diminish conditions like heart disease, certain cancers, stroke, and type 2 diabetes, and lower greenhouse gas emissions at the same time.
So it’s clear that all of the studies suggest that investing in climate change mitigation would also pay dividends in better health. However, the wide variation in models, health outcomes, time frames, and geographic scales means that it is difficult to compare the results of different studies, the researchers note.
And there are other complexities. The health benefits from cutting carbon emissions aren’t distributed equally. In some cases there can even be downsides. If people replace red meat consumption with dairy, carbon emissions associated with their diet can actually increase. And sugar and junk food are often relatively low in greenhouse gas emissions, so it’s possible to have a climate-friendly diet that isn’t particularly healthy.
Still, focusing on health benefits could encourage individuals to shift their behavior in ways that reduce greenhouse gas emissions. It could also help convince governments to adopt policies to reduce emissions. The health benefits of fighting climate change offset a significant share of the costs of these policies, the researchers say. Moreover, the health benefits tend to materialize sooner than the climate benefits, creating an immediate justification for action.
“Mitigation policies are very likely a ‘win-win,’ improving health in the shorter term while decreasing the magnitude of climate change-related health risks later in the century,” the researchers write.
Source: Chang KM et al. “Ancillary health effects of climate mitigation scenarios as drivers of policy uptake: a review of air quality, transportation and diet co-benefits modeling studies.” Environmental Research Letters. 2017
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