The connection between meat production and climate change and environmental degradation is widely recognised. We know that the livestock industry is responsible for 14.5% of greenhouse (GHG) emissions globally, while accounting for 40% of arable land and 29% of agricultural freshwater use.

Industrialised livestock production also results in large quantities of animal waste which leads to significant air, water and soil pollution. Because the land cannot absorb the large quantities, soils are over-fertilised and release toxic runoff which can flow into bodies of water and have significant ecological impacts. Industrial meat production is an environmental disaster, not to mention a major threat to public health and animal welfare (though these need their own articles to do them any justice).

Environmental groups have been campaigning to encourage reduced meat consumption and promoting more plant-based foods because of their effects on health and the environment. Indeed, there has been a huge increase in the number of individuals following vegan or plant-based diets in many parts of the world. In Great Britain for instance, the number of vegans quadrupled between 2014 and 2018. However, global meat consumption continues to rise, in large part due to population growth and rising incomes in large middle-income countries such as China.

The alternatives

Livestock production clearly presents serious threats to the environment and meat alternatives have been praised for their potential to significantly reduce GHG emissions. But their environmental footprints vary.

There are plant-based meat alternatives, such as Quorn or the Beyond Burger (the ‘burger that “bleeds”’), which aim to mimic the look, feel and even the taste of meat but that are made purely of plant-based ingredients. Cultured meat, or meat that is made of real animal cells, is produced in a lab or bioreactor rather than from a slaughtered animal. Innovation in this space has been rapid, with the first products expected to hit the shelves later in 2019.

Researchers from the Oxford Martin School evaluated the potential climate impacts of cultured vs. conventional meat using a climate model comparing the effects of carbon dioxide, methane and nitrous oxide.

The researchers sought to capture the different effects different GHGs have on the environment. Methane has a larger warming effect than carbon dioxide but remains in the atmosphere for a fraction of the time. Because labs primarily use carbon dioxide emitting energy sources, and carbon dioxide stays and accumulates in the atmosphere for far longer than other GHGs, the researchers found that it’s possible the production of cultured meat will result in more warming in the long term.

The authors concluded that cultured meat is not inherently better environmentally than conventional meat, and that its impact depends on the availability of low carbon energy sources and the specific methods of production.

Plant-based diets have been shown by research to have less environmental impact than diets high in meat and health bodies point to how they are better for human as well as planetary health. For instance, researchers have calculated it takes 250 times the GHG emissions to produce a gram of beef or lamb protein than the equivalent in legume protein, which is used in many plant-based meat alternatives.

One systematic review of scientific literature found that reductions in the degree of animal-based food consumed was generally proportional to the reduction in environmental footprint. So vegan diets seem to have the least impact while diets high in meat have the most.

Interestingly, it also found that the production of food has the greatest climate impact, rather than transport or processing, so it’s still better to eat less meat than to eat locally produced meat without reducing overall consumption.

Potential downsides of plant-based

With such a large body of evidence, the benefits of switching to a plant-based diet seem irrefutable. But, like swapping conventional meat for cultured, simply switching to a plant-based diet ignores potential social and environmental impacts.

Soya bean, for example, is a popular ingredient in many meat alternatives, such as veggie sausages and burgers. Rather than offering us a sustainable escape from the perils of our current meat production, increasing soya bean production is leading to grassland conversion, deforestation, loss of soil carbon, emissions of carbon dioxide and nitrous oxide, and nutrient pollution in rivers, lakes and estuaries. Brazil recently recorded a huge spike in deforestation in the Amazon–88.4% in June compared to the same time last year–in part due to the new government’s push for clear-cutting. Much of this land is being converted for soya bean production, along with grain production, ranching and mining.

In terms of its social impact, the concentration of farmland has pushed small farmers and communities off the land, for the benefit of a few large-scale farmers. Jair Bolsonaro has been working to massively dismantle existing environmental laws and protections for indigenous people in the Amazon in a bid to convert areas of the rainforest to spur economic growth.

These examples are not to say that reducing meat consumption, or eventually swapping conventional meat for cultured meat, are not worth pursuing. The point is that our food choices are all part of complex systems. At the moment, following a plant-based diet with less or no meat appears to beat eating cultured meat at the current levels and production methods. However, with innovations in sustainable energy sources, this could change.

It’s also important to know where your food comes from. We should be focussing on eating local, plant based food which is both better in terms of the GHG emissions involved in the production process but also needs to travel less to arrive to consumers.

The role of policymakers

The food you put on the table is a highly personal choice, but there are challenges and opportunities for policymakers here as well. Lower carbon diets luckily also map onto the official guidelines of many national health bodies such as the US Dietary Guidelines, the Mediterranean Diet and the New Nordic Diet. Sweden and Brazil have even added environmental priorities to their dietary guidelines. Several governments have also already agreed to regulate the cultured meat market and this will have a huge impact on the future of the industry, including human and environmental health.

With several of the Sustainable Development Goals connected to diet – agricultural production, water use and climate change – shifting our eating habits is a step towards transforming our unsustainable food systems.[/fusion_text]