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Eating the planet: what our diets and population growth mean for the environment

A new report reveals that global adoption of current food consumption patterns in G20 countries would ruin our chance of meeting climate and sustainability targets, exceeding the planetary boundary for food-related emissions by almost three-fold and requiring up to seven Earths to support.

Person eating burger
Person eating burger

Diets for a Better Future, published by EAT, demonstrates that even national dietary guidelines in almost all G20 countries are incompatible with emissions reduction targets under the Paris Agreement, which aims to restrict warming to “well below” 2 °C and ideally 1.5 °C. The authors emphasise the importance of a drastic dietary reduction in animal products and that sustainable, healthy diets will become impossible if our population exceeds 10 billion people, as is expected to happen in the latter half of the century.

The neglected food factor

Agriculture already uses 40% of the Earth’s land area and is the primary driver of deforestation, habitat destruction and biodiversity loss. Food production is responsible for a quarter of the world’s greenhouse gas emissions, equalling the contribution made by electricity generation and exceeding that of industry.

“Global food production is the single largest human pressure on Earth, threatening local ecosystems, driving a sixth mass extinction of species, and impacting the stability of the entire Earth system. Feeding and producing food for our current population of 7.7 billion people accounts for approximately 12.5 Gt CO2eq or 24% of annual greenhouse gas (GHG) emissions.” – Diets for a Better Future, EAT, 2020

The landmark 2019 EAT-Lancet report concluded that achieving healthy, sustainable diets for 10 billion people by 2050 is possible but requires profound transformation to eating habits and food production. Notably, it states that exceeding this population threshold will make this outcome “increasingly unlikely”. However, the UN predicts a population size close to 11 billion by 2100.

Around 820 million people suffer from hunger and that number has been increasing in recent years due to progress not keeping up with rapid population growth in the hardest hit areas. Another 2 billion and counting are considered overweight or obese due to unhealthy diets, which are also fuelling environmental destruction.

The report notes that despite the huge impact of food systems on climate change, biodiversity and health, they have largely been omitted from international policy agendas. It warns that if we continue on current food and population trajectories, we will not meet either the Paris Agreement or the Sustainable Development Goals (SDGs).

Feeding the climate crisis

To have a chance of limiting warming to 1.5 °C, emissions need to peak in 2020 and halve every decade, achieving net-zero emissions no later than 2050. To meet this target, the EAT-Lancet Commission concluded that emissions from food cannot exceed an annual carbon budget of 5.0 Gigatonnes (Gt) CO2-equivalent.

The report states:

“Current food consumption trajectories and estimated growth of another 2 billion people on the planet by 2050 will largely exceed food’s maximum allowable “carbon budget”. Behavioral changes associated with rising incomes and urbanization are driving a global dietary transition in which traditional diets are being replaced by more homogenous diets higher in animal source foods. If this trend is not broken and reversed, emissions from food production will nearly double by 2050.”

In fact, annual global food-related emissions, at 5.6 Gt, already exceed this budget, with G20 countries responsible for two-thirds of them. Currently, the top five most populous countries in the G20, China, India, United States, Indonesia, and Brazil, are also the countries with the highest total emissions from food production. Global adoption of G20 countries’ current food consumption patterns would require up to 7.4 Earths to be sustainable.

The authors argue that if everyone followed their country’s national dietary guidelines, food-related greenhouse gas emissions would be reduced relative to today but would still exceed the planetary climate boundary for food by almost two-fold and we would still require up to five Earths. The “Planetary Health Diet”, proposed by the EAT-Lancet Commission, would result in an almost 50% reduction, mainly through decreased red meat and dairy consumption. In countries that still have widespread malnutrition, including India and Indonesia, food-related emissions would actually increase slightly if either diet was universally adopted.

“Feeding 10 billion people a healthy flexitarian diet (e.g. Planetary Health Diet) within the 5 Gt CO2eq GHG planetary boundary for food production requires a theoretically near universal adoption of healthy diets across the globe by 2050, improvements in technology and management at the farm level and halving food loss and waste.” – Diets for a Better Future, EAT, 2020

It is clear that nations must adapt their dietary guidelines to take into account environmental sustainability, and while sustainable food systems must indeed be included in international policy discussions, so must sustainable population. The sooner we stabilise our population, the more likely we are to be able to feed the world without destroying the environment. Empowering, choice-based population solutions are key to meeting the SDGs and achieving a better future for people and planet.

Population and the Sustainable Development Goals


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