Consider the following (seemingly unrelated) realities: 1) An estimated 7 million deaths are attributed to air pollution every year; 2) over half of the U.S. population does not attain recommended minimum levels of daily exercise, contributing to rising rates of obesity and related diabetes, cancer and heart disease; and 3) greenhouse gas emissions -- responsible for the global climate crisis -- rose the fastest (roughly 2 percent per year) in the past decade, approximately twice the rate from the period between 1970 and 2000.
What do these three threats to our health and our planet have in common? Fossil fuels. Fossil fuel combustion accounted for approximately 78 percent of the total increase in carbon dioxide between 1970 and 2010. Of course burning oil, gas and coal also release pollutants such as fine particulates, e.g. PM2.5, known to be harmful to human health. Therefore, cleaner energy can help both reduce the heating of the planet, while saving lives from air pollution. Greenhouse gas mitigation strategies could avoid about 1 to 4 million deaths annually by 2050. As for the costs of cleaner energy sources, monetized human health benefits associated with improved air quality can offset between 26 to 1,050 percent of the cost of U.S. low-carbon policies; in other words, the value of health dividends could swamp the costs of striving for an energy efficient, low-carbon economy.
These numbers are not at all surprising, given US EPA estimates of a return of $30 for every dollar invested in reducing air pollution through the Clean Air Act. Of course health benefits will be even greater in highly polluted cities, for example, in East and South Asia.
Addition health and economic benefits can further augment those that stem from improved air quality. For example, studies of the cost of heat induced reductions in labor productivity from global warming approximate $2 trillion per year by 2030. Moreover, as the world emulates Western lifestyles with automobile-dependent transportation and meat-based diets, upward trends in chronic diseases, such as diabetes and heart disease, are now occurring throughout the world.
Herein lies even more golden opportunities for public health through: first, adopting more alternative modes of transportation, especially those that promote "active transport" by foot or by bicycle, alongside of effective public transportation; and second, by reducing meat in the diet.
In the U.S. upper Midwest region alone, if half of short car trips (under 5 miles round-trip) were achieve by bicycle during the summer, approximately 500 deaths could be avoided annually due to benefits from physical fitness. Active transport in Shanghai, China, could reduce colon cancer risk by 48 percent in men and 44 percent in women, and bike commuting in London could lower ischemic heart disease by 10 to 19 percent.
In the U.S., comparing cities with highest versus lowest levels of active transport, obesity rates are 20 percent lower and diabetes rates are 23 percent less. Bicycling commuters in Copenhagen have a 39 percent reduction in mortality rate compared to non-cycling commuters.
Knowing the co-benefits to both health and the environment, "Meatless Mondays" might expand across more days of the week. In the UK, if 50 percent of meat and dairy in the diet were replaced by fruit, vegetables and cereals, greenhouse gas emissions might drop by 19 percent, while at the same time potentially 30,192 to 43,592 deaths could be averted per year by the reduction of saturated fat in the diet. One caveat, however, is that meat in the developing world provides essential protein and micronutrients -- so this recommendation is geared primarily to the "supersized" world.
In conclusion, current rates of chronic disease alongside continued rising trends in fossil fuel-based energy consumption that causes climate change (more accurately called the global climate crisis) present daunting risks to civilization. Yet, the interdependence of these challenges affords a golden opportunity to solve both simultaneously. Last week's UN Climate Summit offers hope that political will and leadership have finally arrived; may we look forward to a healthier, low-carbon economy in the very near future.
This post is part of a month-long series produced by The Huffington Post in conjunction with a variety of events being held in September recognizing the threats posed by climate change. Those events include the UN's Climate Summit 2014 (that was held Sept. 23, 2014, at UN headquarters in New York) and Climate Week NYC (Sept. 22-28, 2014, throughout New York City). To see all the posts in the series, read here.