In 2015, more than half of the world’s CO2 was emitted by plants, according to the United Nations Food and Agriculture Organization.
These days, more and more people are relying on plant-based foods, which have lower greenhouse gas emissions than animal-based diets.
The United Nations estimates that more than 90% of the planet’s CO 2 emissions come from food.
But, is it true that the world has lost out on an opportunity to improve the quality of our food?
The first step to finding out is to ask.
So, with the help of researchers from the University of Colorado, a team of scientists have gone out to some of the biggest agricultural centres in the world and asked about their CO2 emission trends, using a new tool called the Global Food Index (GFI).
They have also been able to track down a number of plant-derived products that have a lot in common with plant-eating foods.
This is where the challenge lies, is finding out which products are best suited to our lifestyles.
So how do we go about determining which products we should buy, and which ones should we avoid?
“One of the big challenges is the fact that the average person is very poor in understanding the carbon footprint of a product,” says Dr David Joly, from the UCL Institute of Food and Agricultural Sciences.
“So they’re not really seeing the real carbon footprint.”
This lack of understanding could be one of the main reasons why some products have high CO2 and others low.
The authors of the report found that the products they tested were a bit more diverse than the average consumer.
“A lot of the plant-eaters are going to be vegans or vegetarians, whereas some of them are going for meat,” Dr Joly explains.
“The average consumer will not be eating many animal products, so they’re probably not going to really be exposed to plant- based food, so there’s a little bit of variability.”
The researchers also took into account the impact of regional food systems on CO2.
“Some countries are producing a lot more meat, so it’s not going out to the country as a whole but rather in regions, and therefore the overall impact of production on CO 2 is less,” Dr Verena Scholz from the Institute of Plant Nutrition, Food and Development, tells BBC News.
“There’s a big range of regional production systems, and in particular the use of biofuels in Africa.”
The results showed that meat consumption has risen by more than 50% in Europe and the Americas, while the global average is down by 20%.
There’s some evidence that the shift to a vegetarian diet has been successful in reducing CO2 in the food chain.
“Meat consumption is on the decline worldwide, but in parts of Africa and Asia, where meat is still the main source of protein and where CO2 is a big concern, it’s still a big problem,” Dr Scholzy says.
“If you look at the numbers in Africa, they’re going up and up, and the global CO2 per capita is increasing.”
She says there is no reason to assume that people will suddenly switch to a plant-food diet anytime soon.
“For a plant food diet, it has a good chance of being successful for the planet, and we have to be really careful,” Dr Sichowsky says.
In fact, Dr Schollz says, there’s actually a lot to learn from the success of plant food diets.
“When people switch from animal-eating diets to plant food, their overall carbon footprint goes down by 30% to 40%,” she says.
For example, if you eat a plant protein-rich diet, the carbon that you emit by eating meat will decrease by around 20%.
“So if you were a vegetarian, you could have avoided about 50 tonnes of CO2 from meat,” she explains.
However, some products that may have lower emissions than others have been around for a long time, including rice, soy, and wheat.
Dr Jouls team have found that in terms of their carbon footprint, rice is by far the worst offender.
“You can see in this table that rice is one of those products that is in the top 10, so we can definitely see that this is the product that is probably most environmentally damaging,” Dr Ainsworth says.
If you’re a plant eater, this is a good indicator that you should not eat rice.
The researchers say the next step is to look at which plant-related products are more popular among people, so that they can be targeted to a wider audience.
“It’s really important that we start looking at the food supply chain and look at what products people are actually buying, to try and figure out what’s going on,” Dr Koehler says.
And if the food is not really suited to a particular lifestyle, then it may be time to rethink what you’re doing with it.
“We should really be looking at our food supply chains and ask