Plant-based diets needed to limit climate change

Major changes to diet and farming are needed to allow the Earth to keep feeding the global population. The study's lead author told DW there's "little chance of staying within environmental limits" if no action is taken.

A plant-based diet, improved farming practices, and reduced food waste are needed to keep the negative environmental effects of the food system within the Earth's limits, according to a new study in the journal Nature.

The study found that between 2010 and 2050, due to expected changes in population and income levels, the environmental effects of the food system could increase by 50–90 percent if action is not taken.

These levels would be "beyond the planetary boundaries that define a safe operating space for humanity," the study said.

Read more: Let's talk about meat

Nature and Environment | 08.03.2018

"If socioeconomic changes towards Western consumption patterns continue, the environmental pressures of the food system are likely to intensify, and humanity might soon approach the planetary boundaries for global freshwater use, change in land use, and ocean acidification," the study found.

In addition to those boundaries, "ecosystems could be at risk of being destabilized and losing the regulation functions on which populations depend."

Read more: 'Serve less meat and use renewable jet fuel'

In terms of food waste, it is currently estimated that more than a third of all food that is produced is lost before it reaches the market, or is wasted by households, according to the study, which was funded by Scandinavian food system think tank EAT.

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Plant-based diets a must

"The food system has little chance of staying within environmental limits without dietary changes towards more plant-based diets," the study's lead author Marco Springmann told DW.

That diet would include plenty of vegetables, fruits, legumes and nuts, and could also include small amounts of animal products, but should have less than one portion of red meat — beef and pork — per week.

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Springmann, a senior researcher at the Oxford Martin Programme on the Future of Food, told DW that animal products have greater environmental impacts, particularly on climate change, because animals need to be fed large amounts of feed that require environmental resources in the production process.

Read more: Demand for animal feed threatens a tropical paradise

He said cows need to be fed 10 kilograms of feed on average to gain 1 kilogram of body weight. For pigs, that ratio is about 6, and for chickens 3-4. Cows also produce methane, a powerful greenhouse gas, during their digestion process.

Eating naturally

With everything from meat contamination scandals to concerns about agriculture's climate change impact in the news these days, more and more people are turning to a vegan diet. But, there are other ways to eat in an environmentally-friendly way too. Free-range meat products are now commonplace. Rarely, though, are cows raised in such a paradise as this alpine meadow.

Vegan cuisine

In the 1970s and 80s, eating vegetarian, and especially vegan - abstaining from animal products completely, like milk and eggs - was not part of the mainstream. Nowadays, things are changing. Jonathan Safran Foer's 2009 book "Eating Animals" sparked thought about the meat people eat. More vegan restaurants are sprouting up all over the place; here are some dishes from 'Pêle-Mêle' in Berlin.

Carbon and water impact

Eating vegan can reduce carbon footprints and water usage worldwide. The UN's Food and Agriculture Organization estimates that the meat industry generates nearly one-fifth of human-made greenhouse gas emissions contributing to climate change. Scientists also say that 13000 to 15000 liters of water are needed to produce just one kilogram of beef.

Pork with a smile

With the recent scandal surrounding Dutch horsemeat being sold as beef, more Europeans are now simply choosing to eat meat less. But, for those that can't do without, the "Meine kleine Farm" (My little farm) concept tries to achieve transparency with consumers. It aims to give each animal it sells as meat a proper identity.

Knowing what you're getting

The Potsdam-based farm has a website showing the living conditions of the animals and giving customers a chance to vote online about which animal they want slaughtered next. Since they mainly sell to customers in the nearby region, the 'Meine kleine Farm' project also helps to keep transportation routes - and thus greenhouse gases - to a minimum.

Local food at farmers' markets

Eating locally and in season also helps reduce greenhouse gases because it cuts out long transportation routes. Canadians Alisa Smith and J.B. MacKinnon argued for local cuisine in their book, "100-mile diet: A year of local eating." The couple spent one year eating foods from within one hundred miles of their home. Self-preserved foods got them through the winter.

Large-scale monocultures are vulnerable

The modern industrial agriculture practice of cultivating monocultures, such as corn and soy, can make the crops more susceptible to pests and diseases. This, in turn, promotes the widespread use of pesticides. Small-scale farmers, on the other hand, often promote crop diversity which makes plants naturally more robust, even in periods of drought.

Berlin's Princess Garden

Cultivating one's own crops is possible even in big cities, as shown by the "Princess Garden" project right in the middle of Germany's capital, Berlin. Crops are grown and consumed locally, with food dishes offered as business lunches at an on-site café. The urban farmers here say gardening raises awareness about the environment and, since the garden is shared, they make friends along the way too.

Reduce food waste, save resources

With Germans throwing away an estimated 20 million tons of food a year, food-sharing has become one of the latest environmentally-friendly trends. Restaurants or grocery stores donate still-edible food that they can no longer use to charity organizations. Foodsharing.de is an internet portal where people can swap food they won't be able to eat.

Healthy benefits

Many dietary experts argue that a vegetarian or vegan diet can be good for your health too. Various studies show that a decrease in daily meat consumption may reduce the risk of cancer, cardiovascular disease, diabetes and obesity.

Improved farming practices

Some farming practices can lead to negative environmental impacts, the study found. This includes excess fertilizer finding its way into river systems and oceans, where it can lead to oxygen-depleted dead zones, while other farming practices might make inefficient use of water resources, said Springmann.

"When taken together, we find that improvements in farming practices and technologies can lead to large reductions in the environmental impacts of the food system," Springmann said. These "are required, together with dietary changes towards more plant-based diets and reductions in food loss and waste, to stay within environmental limits," he added.

The study comes just after the Intergovernmental Panel on Climate Change (IPCC) released a report outlining what we need to do to keep global warming below 2 degrees Celsius (3.6 degrees Fahrenheit).

The 2015 Paris Agreement saw the world agree to keep global warming less than 2 degrees Celsius above pre-industrial levels, and preferably below 1.5 degrees Celsius.

But the report found that the difference between those two numbers was significant and could potentially save hundreds of millions of people from poverty.