So, you want to reduce your carbon footprint? You might consider improving your diet.
It seems that healthy food isn’t just good for your body, it can also decrease your impact on the environment.
Scientists say that food production including growing crops, raising livestock, fishing and transporting all that food to our plates is accountable for 20 percent to 30 percent of total global greenhouse gas emissions.
In addition, 33 percent of the ice-free land on our planet is being used to produce our food, researchers state.
But modifying our diets could change that.
A new research released Monday in PNAS discovered that if citizens in 28 high-income nations such as the United States, Germany and Japan actually sticked to the dietary recommendations of their own governments, greenhouse gases related to the production of the food they eat would drop by 13 percent to 25 percent.
At the same time, the amount of land it takes to produce that food could fall by as much as 17 percent.
“At least in high-income countries, a healthier diet leads to a healthier environment,” said Paul Behrens, an environmental scientist at Leiden University in the Netherlands who led the work. “It’s win-win.”
To come to this conclusion, Behrens turned to Exiobase, an enormous input-output database that represents the entire world economy. It helped him to track not only the environmental cost of growing and producing the various kinds of food we eat, but also the cost of the machinery used in the production of that food, and the cost of getting it into our supermarkets and finally onto our plates.
The database also takes into account that some countries are more capable of producing some food than others. For example, growing tomatoes in England takes more energy than growing them in Spain, where it is warmer. correspondingly, a steak from a grain-fed cow in England has a smaller environmental impact than one from a grass-fed cow in Australia.
“It’s excellent that we have this information,” Behrens said. “You can trace the impact of any consumption across the world.”
For this study, Behrens gathered data on the average diets of people living in 39 countries as well as the dietary recommendations published by governments in those countries. To ensure the outcomes represented the recommended ways of eating and not just eating less, he kept the calorie counts of both diets the same, and only adjusted the percentage of the different food groups that people truly consume, and how much their governments propose they eat.
Next, he inserted those data points into Exiobase and compared the result.
In particular, he looked at three ways the environment is influenced by our diets – greenhouse gas emissions, land use and eutrofication, which is the addition of nutrients to water sources that can cause toxic algae blooms and lack of oxygen in the water. Eutrofication is typically caused by the discharge of animal waste (dung) and plant fertilizer.
The results were far from uniform, but in broad strokes, he found that the richest countries would lesser their environmental impact if their citizens followed nationally recommended diets, mainly because most of these recommendations call for a considerable reduction in the quantity of meat citizens consume.
“On the whole, meat is worse than other types of food because every time something eats something else, you get a loss of energy,” Behrens said. “Eating any animal is going to have more of an impact compared to other food groups.”
Poorer countries such as India and Indonesia would see their environmental impact go up, mostly because the nationally recommended diets call for more calories than many citizens consume in those countries.
Still, the overall effect, if everyone followed nationally recommended diets, would be a decrease in greenhouse gases, eutrofication and land use, he said.
A few countries, including Britain, Switzerland and China, have acknowledged that their dietary recommendations will also help establish a healthier Earth, but that message is seldom transmitted to citizens, Behrens said.
He thinks it’s a lost opportunity.
“Dietary recommendations can be a great way to talk about human health and the health of the environment,” he said. “The main point is you can win both ways.”
