Previous estimates put the figure closer to 20 per cent, but this study is the first to incorporate land use change overseas, increasing the estimate of carbon dioxide emissions attributed to food consumption in this country from 152 megatonnes to 253 megatonnes.

Land use change, mainly deforestation, is a major source of climate changing emissions. Each year world-wide, an area of forest equivalent to half of England is lost. The expansion of the food system is the biggest driver behind this as land is cleared to grow crops and rear animals.

Given the extent of food consumption on the UK’s overall emissions, WWF-UK and the FCRN are calling for a radical change to the country’s food system to help stop deforestation and reduce the scale of emissions from the food chain.

The new report entitled How Low Can We Go: an assessment of greenhouse gas emissions from the UK food system and the scope for reduction by 2050 assessed various scenarios that explored how these changes might look. Both technological and behavioural initiatives were tested, including decarbonisation of the energy used in the food chain, improved efficiencies and changes in consumption of meat and dairy products.

If the food industry is to play its part in keeping temperature rises below two degrees, emissions need to be cut by at least 70 per cent by 2050. The report concludes that no one solution alone can reduce emissions to this extent. WWF-UK and FCRN are urging Government and industry decision-makers to recognise that a focus on technology alone is not enough – food consumption patterns need to change too.

Mark Driscoll, head of WWF-UK’s One Planet Food programme said: “The full impact of our diets on climate change is astonishingly high – this report shows that. This makes the target to cut emissions by at least 70 per cent by 2050 a daunting task, but not an impossible one. We must stop chewing over some of the issues and start making change happen – both in terms of technology and behaviour.”

Tara Garnett, head of the FCRN said: “We now know enough to conclude that the food system contributes very substantially to the problem of climate change. We also know enough about where and how the impacts arise to start doing something about them. Business as usual – and even business as usual ‘lite’ – is no longer an option.”

In terms of the impacts of food consumption the report found:

• The food chain’s contribution to overall UK consumption-related emissions is 20 per cent. However, when land use change is included, this increases to 30 per cent.
• All stages of the UK food chain give rise to emissions, with the breakdown as follows: production and initial processing (34 per cent); manufacturing, distribution, retail and cooking (26 per cent) and agriculturally induced land use change (40 per cent).
• Livestock farming accounts for 57 per cent of agricultural emissions and is also responsible for three-quarters of land use change emissions.

Solutions-wise, the report concluded that there is no silver bullet to achieve such reductions – a combination of activities and changes will be required. These include:

• increasing production efficiency, including improved crop yields and changes to animal feeds to reduce methane emissions
• a significant switch to non-carbon fuels and increased energy use efficiency, and
• changes in the types of food we consume.

The idea of collaboration between producers, processors, retailers, NGOs and Government, is highlighted in the Government’s recently published Food 2030 document, which sets out a vision for UK food. This should be applauded. The role of sustainable diets and a commitment to defining them will also be an important step.

Dietary changes will also ease land pressures, in terms of reducing the amount of land needed to produce the food we consume. While this study did not consider the impact of diet on land use change in detail, nor deal with the issue of land quality, and its potential to produce different types of food, these ideas will be dealt with in a follow-up study tackling the question of how changing consumption will affect land use.