The Impact of What We Eat on Climate Change

The Impact of What We Eat on Climate Change


Michael Garko, Ph.D.

Nationally Syndicated Host and Producer of Let’s Talk Nutrition


What we eat matters, not only with respect to our own individual health but to the health of the planet. Just as there are certain foods that harm human health, there are foods that potentially harm the planet. In particular, meat and dairy production and consumption are among the usual suspects recognized as harming the environment and climate of the planet by the creation of greenhouse gases. Some would even contend that the consumption of meat- and dairy-related products are deleterious to human health. The argument is that consuming large quantities of beef and processed meats exposes people to toxins and puts them at risk for heart disease, cancer and obesity, among other health problems.

The June, 2016 issue of Health and Wellness Monthly focuses on climate change and what we eat. Particular attention will be devoted to strategies that would help mitigate the impact of what we eat on climate change.

Hamerschlag (2011), senior analyst for The Environmental Working Group (EWG) (suggests that American’s possess a voracious appetite for meat and dairy as evidenced by their consumption of billions of pounds annually from billions of animals. It is important to recognize that producing such large quantities of meat and dairy products harms the planet not only in terms of creating greenhouse gases which warm the planet but also in terms of the large amounts of pesticides, chemical fertilizer, fuel, feed and water required to produce them. Further, producing billions of pounds of meat from billions of animals generates large amounts of toxic manure and wastewater which end up polluting groundwater, rivers, streams and oceans (see Hamerschlag, 2011).

In terms of what we eat, some may believe that it is primarily the production and consumption of red meat that harms the planet. As it turns out, different types of meat and how they are produced result in varying deleterious effects on humans and the planet’s climate. Lamb, beef, pork and farmed salmon, along with cheese, are reported to generate the most greenhouse gases (Hamerschlag, 2011). These greenhouse-intensive foods require the most resources (i.e., primarily chemical fertilizers, feed, fuel, pesticides and water) pound for pound and produce greater quantities of polluting manure.

From the list of greenhouse-intensive foods mentioned, lamb, beef and cheese in that order produce the highest emissions because they are derived from ruminant animals, which generate more methane (CH4), a gas 25 times more potent than carbon dioxide (CO2), require more energy-rich foods and produce more manure that do pigs and chickens (see Hamerschlag, 2011).

What livestock are fed has important implications for the creation of greenhouse gases. That is, the majority of livestock in the United States are fed and fattened on fishmeal, corn, soybean meal and other grains. To grow all the feed to fatten the livestock requires 149 million acres of cropland, 76 million kilos (167 million lbs) of pesticides and 7.7 billion kilos (17 billion lbs) of nitrogen fertilizer. Chemically speaking, when nitrogen fertilizer is applied to the soil, it generates nitrous oxide (N20). When compared to CO2, N2O has 300 times the warming effect. Hence, N2O emissions generated from fertilizer application to grow grain crops to feed livestock is a major source of greenhouse gases warming the planet (see Hamerschlag, 2011).

So what are carnivores and dairy-lovers to do? One would most likely have better odds in becoming an astronaut for NASA than converting them to become vegetarians or vegans. Even if everyone in the United States became a vegetarian, which would be equivalent of removing 46 million vehicles off the road or not driving 555 billion miles, this would result in only a 4.5% reduction in carbon emissions, one of the main greenhouse gas culprits in global warming (Hamerschlag, 2011).

A better strategy would be to persuade people that they can and should reduce their individual carbon footprint to help reduce the production of greenhouse gases, and thereby, moderate the effects of climate change and global warming. While it will not stop climate change or global warming, convincing people to abstain from eating meat at least one day a week has the potential to make a difference, assuming everyone participated in the program.

Compared against other climate-saving actions, the Hamerschlag (2011) offered at least four documented ways in which eating less meet can help reduce a person’s carbon footprint:

If you eat one less burger a week, it’s like taking your car off the road for 320 miles or line-drying your clothes half the time.

If your four-person family skips meat and cheese one day a week, it’s like taking your car off the road for five weeks – or reducing everyone’s daily showers by 3 minutes.

If your four-person family skips steak once a week, it’s like taking your car off the road for nearly three months.

If everyone in the U.S. ate no meat or cheese just one day a week, it would be like not driving 91 billion miles – or taking 7.6 million cars off the road (Hamerschlag, 2011, p. 12).

Another strategy to help slow the pace and moderate the effects of climate change and global warming, and thereby, create a “greener Earth” would be, according to Hamerschlag (2011), to produce and consume more organic, grass-feed and pasture-raised livestock and grow more organic crops to feed humans and the ruminant animals consumed for food.

Yet, another strategy for individuals to reduce their carbon footprint is buy and eat locally produced and grown food products because for example fruit, vegetables, meat and milk produced closer to home result in fewer petroleum-based transport miles compared to foods trucked cross country to people’s tables. However, despite the environmental impact of the large distances (the average distance traveled for food in the U.S. is estimated at 4,000-5,000 miles) involved in transporting food across the country, Weber & Matthews (2008) contend that “[s]hifting less than 1 day per week’s (i.e., 1/7 of total calories) consumption of red meat and/or dairy to other protein sources or a vegetable based diet could have the same climate impact as buying all household food from local providers” (p. 3512). In other words, eating less red meat or dairy products may be a more effective strategy to reduce food-related climate effects in terms of what people eat. Weber & Matthews (2008) also contend that the large quantities of greenhouse gas emissions associated with producing food make food production matter more environmentally than “food miles” or otherwise the distance food is shipped.

Similar to what Weber & Matthews argue, Popp et al. (2010) contend that reducing meat and milk consumption and improved agricultural practices have the potential to reduce substantially global greenhouse gas emissions.


Climate change is real. The purpose of June, 2016 issue of Health and Wellness Monthly was to focus on what we eat as a factor contributing to climate change and sketch those strategies that would help to mitigate the impact of what we eat on perhaps one of the greatest threats to the health and life of the planet and consequently our own health and lives.

Perhaps the best approach to slow the pace of climate change and global warming would be to invoke all the food production and consumption strategies mentioned above: (1) produce and consume more organic, grass-feed and pasture-raised livestock, (2) grow more organic crops to feed humans and the ruminant animals consumed for food (3) persuade people to consume less meat and dairy products and (4) buy and eat locally grown food.



Hamerschlag, K, (2011). Meat eater’s guide to climate change + health. Retrieved from

Popp, A., Lotze-Campen, H. &  Bodirsky, B. (2010). Food consumption, diet shifts and associated non-CO2 greenhouse gases from agricultural production. Global Environmental Change, 20 (3): 451.

Weber, C.L & Matthew, H.S. (2008). Food-miles and the relative climate

impacts of food choices in the United States. Environmental Science & Technology, 42 (10), 3508–3513.


Suggested Citation: Garko, M. (2016, June). The impact of what we eat on climate change. Health and Wellness Monthly. Retrieved (insert month, day, year), from