Human CO2 contribution

We humans emit the equivalent of about two tons of carbon dioxide per person per year through the growing, processing and digesting the food we eat. That means humans are responsible for 20% of the CO2 dump into the
atmosphere.

This study revealing these numbers is from a team of researchers at the Universidad de Almeria (UAL) in Spain and is the first one to factor in the environmental impact of digestion. What that really refers to is human
excrements and the contribution to water pollution, primarily with nitrogen and phosphorous.

It’s a cost analysis of the complete cycle of food. “Food in Spain produces emissions of around two tons of carbon dioxide per person and per year (more than 20% of total emissions per person and per year) and consumes 20 gigajoules of primary energy,” says Ivan Munoz, the lead author of the study.

The International Journal of Life cycle Assessment published the study. It analyses the relationship of the food production and consumption chain with global warming and the acidification and eutrophication (excess of nutrients) of the environment, taking what a person in Spain ate in 2005 as a reference.

Calculations factored in a broad range of relevant data. These included agricultural and animal production, industrial food processing, sale and distribution, preparation and cooking at home, solid waste treatment (food remains and packaging), and human excretion.

Food from animals causes the impact on the environment. Human excretion is number five on the list of carbon dioxide offenders following Agriculture, livestock, fishing and the food industry particularly with water pollution.

Understating the point, Munoz said, “Human excretion contributes significantly to water polluting though providing organic matter and nutrients, such as nitrogen and phosphorus, which fosters the growth of algae a decrease in the level of oxygen dissolved in the water bad smalls and other problems…” He did follow up by saying there is nothing wrong with returning treated fluids back to the environment, but did point out that mixing them into shallow waters was a bad idea.

Source: Spanish Foundation for Science and Technology, Science Daily