This summer has been a rude awakening for many of us. For a long time, the consequences of climate change could feel far away, both in time and location. But record-breaking heat, drought and parched landscapes are making the reality of a changing climate increasingly difficult to ignore.
The science tells us that our own activity as a species is driving climate change. The United Nations confirms that climate change is caused by human activity, particularly the burning of fossil fuels, which increases greenhouse gases such as carbon dioxide in the atmosphere.
But climate change isn’t only changing the weather around us. It’s also putting pressure on the systems we rely on to produce our food. Drought, rising temperatures and changing rainfall patterns can affect crops, animals and water supplies, while agriculture itself places significant demands on land and freshwater.
So how can we make sure we have enough food to feed the current population of 8.3 billion people on the planet, both now and in the future?
How efficient is our food system?
Food production as a whole is responsible for around one third of global greenhouse gas emissions, according to the United Nations.
When we grow crops to feed animals, we are effectively producing food twice – first growing plants and using them to feed animals to produce meat, milk or eggs. Animals use much of the energy and nutrients in their feed simply to live, rather than converting it into food that humans can eat.
The Organisation for Economic Co-operation and Development (OECD) estimates that only around 23% of the energy in animal feed is ultimately converted into human food, with the remainder used largely to maintain the animal’s body. This creates competition for crops, land and water that could otherwise be used directly to feed people. The problem will become more significant as the climate warms: rising temperatures, drought and changing rainfall already affect crop yields and animal health.
Carbon emissions
Animal agriculture contributes to global warming through several different greenhouse gases:
- Cows and sheep produce methane through digestion
- Manure and fertilisers used to grow animal feed release nitrous oxide
- Carbon dioxide is also released through fossil-fuel use, and when forests and other ecosystems are cleared for livestock grazing or growing animal feed
Together, these emissions trap heat in the atmosphere and contribute to rising global temperatures. These statistics by Our World in Data, show that many of the biggest producers of greenhouse gases come from industries that farm animals.
Research shows that, when comparing foods by the amount of protein they provide, beef has an average footprint of around almost 50kg of greenhouse gas emissions per 100g of protein, while lamb is around 20kg. By comparison, grains are around 2.7kg, groundnuts about 1.23kg and peas around 0.44kg.
Animal agriculture also contributes to other environmental pressures, including biodiversity loss, soil degradation and pollution.
The water footprint of our food
Animals require water to drink, but a large proportion of the water footprint of animal products comes from growing the food they eat.
Research by Cranfield University shows that the water footprint of producing British beef have been assessed at more than 15,000 litres for each kilogram. In comparison, vegetable foods need much less water. For example, 1kg of potatoes uses 287 litres of water.
Land and protein
Land use tells a similar story. Producing meat requires land to raise animals and, in many farming systems, land to grow their feed. Producing food directly from plants can therefore be considerably more land-efficient.
Research analysed by Our World in Data compares land area needed for protein produced by different foodstuffs. It found that beef and lamb require vastly more land to produce protein than plant-based sources such as peas and tofu.
This matters for food security. As populations grow and climate change puts additional pressure on agricultural systems, making efficient use of available land becomes increasingly important.
According to Our World in Data, less than half of the world’s cereals are eaten directly by humans: 41% is used for animal feed and 11% for biofuels. It concludes that if people moved towards a plant-based diet, global agricultural land use could be dramatically reduced, cutting out beef having the largest impact of all.
Our daily choices matter
Climate change can sometimes feel like a problem too large for individuals to influence.
While we need urgent action from companies and governments to ensure that climate change goals are set and met, diet is one way we can help to make an impact in our own lives.
The drought this summer is a reminder that our planet’s resources are not limitless. The choices we make about what we put on our plates can be part of creating a food system that uses land and water more efficiently, reduces emissions and is better prepared for the challenges ahead.
Scientists, environmentalists and conservationists have been warning for decades about environmental destruction. One of the most familiar voices is Sir David Attenborough, who celebrated his 100th birthday this year.
In recent years, Attenborough has increasingly focused on the relationship between human activity, the natural world and climate change. His documentaries have brought the scale of the environmental crisis into millions of homes, while highlighting some of the changes we can make to reduce our impact.
One change he advocates is eating less meat and more plant-based food.
Attenborough has said: “We must change our diet. The planet can’t support billions of meat-eaters. If we had a mostly plant-based diet we could increase the yield of the land.”
Where do we start?
At The Vegetarian Society, we advocate for starting with small switches that can add up to create a real impact. By beginning to eat more plants and less meat, we can help to reduce carbon, prevent emissions and save water – playing our part to ensure stronger food security for the future.
