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Our wasted food is a huge environmental problem – and it’s only getting worse


The more scientists study the issue of food waste — and its worrying implications for both the environment and global food security — the clearer it becomes how much of a problem it is. Now, new research is giving us a few more reasons to clean our plates.

A study just out in the journal Environmental Science and Technology concludes that we’re already producing way more food than the world actually needs — but a lot of the excess is being wasted, instead of used to feed people who need it. That’s a big problem for global food security as well as for the climate, given the huge amounts of greenhouse gases that go into producing the extra food — and the study suggests that the problem will only get worse in the future.

Scientists are already aware of how bad food waste is for the environment. Just last week, we reported on the staggering carbon footprint associated with wasted food — the UN’s Food and Agriculture Organization reported that, in 2007, the emissions required to produce all the food that went to waste in the world amounted to at least 3.3 billion tons of carbon dioxide equivalent, more than most countries emitted. This estimate included all the emissions required to produce the uneaten food, including emissions from soil, livestock and the energy required to run a farm.

The new research, which was conducted by researchers from the Potsdam Institute for Climate Impact Research in Germany, suggests that in the future, food waste will grow — and the associated emissions will grow even faster.

“When we’re talking about the future food requirements — what can we do to meet the future food demand — we found that to investigate food waste is a quite crucial aspect,” said the paper’s lead author Prajal Pradhan, a postdoctoral researcher at Potsdam.

The researchers used U.N. data to calculate the difference between the amount of food available in each country and the amount its citizens require in order to be healthy. For each country, there was either more food available than was needed to supply the nation’s requirements — a food surplus — or not enough. The researchers considered food surplus to be equivalent to food waste, as it represents food that was not needed but produced anyway. Presumably, the majority of a food surplus is wasted, although the researchers noted in the paper that some of it is likely used for animal feed or is consumed by humans through overeating.

In order to estimate the greenhouse gases associated with food waste, the researchers turned to data from the FAO on the emissions associated with agriculture. It’s important to note that they did not include emissions associated with the energy required to operate farms, such as the electricity needed to run farm equipment — they only included emissions produced by soil and livestock, mostly nitrous oxide and methane. This means that the emissions reported by the new study are significantly underestimated.  

The study found that the global food surplus increased overall between 1965 and 2010 from 310 extra kilocalories per person per day to 510 extra kilocalories, with the greatest surplus growth rates generally observed in developed nations. As of 2010, 20 percent more food was being produced worldwide than was actually needed to feed the world’s population, and overall the researchers estimated that the global surplus could be used to feed an extra 1.4 billion people. The UN estimates that about 800 million people worldwide suffer from undernourishment, meaning there’s currently enough wasted food in the world to solve the world’s hunger problem nearly twice over — it just isn’t reaching the people who need it.  

The researchers also found that the agricultural emissions associated with all the extra food more than quadrupled between 1965 and 2010, from 130 million tons of carbon dioxide equivalent to 530 million tons. Again, these estimates don’t include the carbon emissions associated with energy use, so the reality is that the food waste’s carbon footprint was even higher — more like 3 billion tons, going by the FAO’s previous research.

Moreover, all of these problems are expected to grow worse in the coming decades. The researchers also conducted a series of projections based on different hypothetical scenarios involving the future world’s energy requirements and population growth and demographics.

They found that the food surplus will continue to grow in most countries, and the global surplus could grow as high as 850 kilocalories per person per day. Future waste-related emissions also increased in every scenario and grew at an even greater rate than the global food surplus — the result of predicted changes in the global diet.

In the future, meat is expected to become an even greater component of diets around the world, Pradhan explained — and meat is particularly energy intensive to produce. Altogether, food waste-related emissions could span anywhere from 1.9 to 2.5 billion tons of carbon dioxide equivalent per year — again, excluding emissions from the energy sector.

The study highlights several important problems in the current global food system. First, the finding that there’s more food than necessary in the world, while undernourishment still remains a global problem, implies that there are serious failings in the distribution of food worldwide.

“So much of poverty and famine aren’t about a lack of resources overall — they’re just distributional [problems],” said Emily Broad Leib, an assistant clinical professor of law and director of the Harvard Food Law and Policy Clinic. “It’s not surprising to see that, and both across countries and within countries this challenge of the food markets really being attainable for certain segments of the population and not for others.”

Addressing this problem, which likely stems in large part from income inequalities in countries where both surplus and hunger exist simultaneously, will be critical to addressing future food security.

And, of course, the study also reiterates the idea that food waste remains tied up with the issue of climate change. While research on the related carbon emissions, themselves, has turned up different values depending on the methods used to calculate them, it’s clear that wasted food is equivalent to the needless release of greenhouse gases, and the problem will only continue to grow unless concrete action is taken to stop it.  

Such action will require steps to prevent food loss on the production side, which experts have suggested could be minimized with infrastructural improvements along the supply chain, as well as action to minimize food waste on the consumer end. The latter may prove to be less straightforward, but experts have proposed a number of steps, including consumer education campaigns and more accurate expiration date labeling on packaged food.

“One of the best outcomes would be getting consumers to make better decisions and have less waste at the household level and have supply chains adjust to that and redistribute that food earlier in the chain,” said Broad Leib.

Such action will likely also be important in helping the international community meet a broader set of sustainability goals outlined by the U.N., which include the goal of cutting food waste in half by 2030, Pradhan said.

“This study can provide a nice basis to show how much food is wasted now, and this information can be used also to achieve this sustainable development goal,” he said.