07/11/2016 03:53 pm ET Updated Jul 12, 2017

The Hidden Consequences of Food Waste


I've spent much of my working life digging into the problem of waste. One of the most important things I've learned is that solving our waste problem requires we look at the whole system, not just our own contribution to it. Sometimes that feels big and daunting, but it also offers many more opportunities to bring about positive changes.

Food waste is especially unforgivable. Millions of people are malnourished or going hungry, not only in developing countries but here in the US, while grocery stores, restaurants and homes are throwing away tons of perfectly edible and nutritious food every day. But the problem is not just the food that's wasted when leftovers go in the trash. It's also all of the greenhouse gas emissions, water, biodiversity loss and soil & air pollution that was generated to create that food only for it to be tossed away uneaten. To understand the full impact of wasting food, we have to look at where that food comes from and where the wasted food goes.

Let's unpack this a bit, starting with snack foods. Not so long ago, big food manufacturers discovered that palm oil could be used instead of butter or trans fats in a vast number of baked goods and other foods. This was very convenient as trans fats had started to get a bad name. You'll find palm oil (or one of its many aliases) in all kinds of food from Quaker granola bars, to Betty Crocker cake mix, to Fritos chips and Dunkin' Donuts.

Palm oil comes from tropical countries like Indonesia, Malaysia and parts of Africa. As we've tried to ditch the trans fats from our diets, demand for palm oil has shot up and these countries are now chopping down thousands of acres of lush tropical rainforests, to clear the way for palm tree plantations. Indonesia has lost over a quarter of its forest since 1990 - an area the size of Germany - which is a tragedy for the indigenous communities and tigers, orangutans and other endangered species which need the forest to survive. Companies have made progress towards buying more responsibly produced palm oil but deforestation still continues, so we should all be mindful of wasting food that may have cost more than just the dollars we paid for it. You can sign this petition to help encourage food companies to stop destroying rainforests for palm oil.

The supply chain for beef has similar problems. This time the trail of destruction leads to the Amazon rainforest. The cattle sector in Brazil has historically been the largest driver of deforestation in the Amazon as ancient forests are cleared to create grazing pastures for cows, that become steaks and burgers. Supermarkets are the largest market for Brazilian cattle products but globally few of them are willing to guarantee the beef they sell is free from deforestation, or violations of indigenous rights in the Amazon.

This isn't the only problem associated with meat production. Aside from the ethical concerns of raising animals for human consumption, livestock is the most significant contributor to nitrogen and phosphorus pollution of streams, rivers and coastal waters worldwide. They're also major emitters of greenhouse gas emissions. In fact, the livestock sector is responsible for about 14% of global emissions, as much as the transportation sector. These problems show why choosing plant based foods over meat can help heal the planet.

The seafood industry is responsible for a different kind of damage. Tuna - one of the most popular sources of affordable protein - is often caught using longlines, as are swordfish and marlin. These are fishing lines over 60 miles long with thousands of hooks on to catch the fish. Longlining is notorious for high levels of 'bycatch', which is the catching of wildlife like threatened seabirds, turtles and sharks that weren't the intended prize. Around 100 million sharks, tens of thousands of sea turtles and tons of other marine life are killed every year. The destructive, inhumane and controversial practice of shark finning mainly takes place on tuna longline vessels. Longliners rarely return to land, and usually offload their catches to other vessels at sea. Out of sight of any kind of enforcement, they often operate illegally and in violation of human and workers' rights.

All this is to show that there are many good reasons to think twice about wasting perfectly good food. But I don't want to leave you with the feeling that our food system is doomed to destroy the planet. Some very real solutions already exist. Ecological farming uses modern techniques to farm with nature, not against it. Rotating crops and planting a diversity of options for example (rather than a single crop for many miles, like the oil palm plantations of Indonesia) plays a crucial role in food security, nutrition and human health as well as increasing resilience to erratic weather changes within a farm.

Phasing out chemical use (such as pesticides and herbicides) in food production is another example. Organic farms support 34% more plant, insect and animal species than conventional farms. For pollinators like bees, the number of different species was 50% higher on organic farms. This is of vital importance, since bees and other pollinators maximise global food production through their pollination services. These are just a few examples of how we can reduce the environmental impacts of food production, more of which are explained here.

We can all play an important role in making sure the food scraps we don't use aren't causing further damage to our planet. Rotting food waste that goes into landfill is a major source of climate polluting methane. Composting is a simple thing we can all do to help prevent this. You don't need a fancy compost bin to get started. I've seen neighborhood composting programs in India and the Philippines that use old barrels, or just long ditches with some worms in!

Whatever you're lucky enough to put on your plate each day, it's clear we all need to appreciate where it comes from and be motivated to make sure every last bite, scrap and rind goes to good use.