The Food Magazine - Click to return to the home page

Changing climate for food choices

24th November 2006

The Government has received its most convincing warning yet that we must all take action to tackle climate change, but failed to emphasise food as one of the main ways to deliver change.

The 700-page Stern Review on the Economics of Climate Change by Sir Nicholas Stern (formerly Chief Economist of the World Bank) warns that climate change could shrink the global economy by 20%.

But Stern also planted seeds of hope by estimating that it could cost just 1% of global gross domestic product to reduce greenhouse gas emissions to a tolerable level, and invest in new low-carbon products and services.

The impact of the food system on human-induced climate change is generally calculated to be around 25 to 30% of the total effect. Yet, identifying food choices as one of the main solutions for climate change gets only a tiny mention in the economist's lengthy report.

To assess the interest in climate-friendly foods, rather bizarrely, the report cites a recent interest in fair trade food as a signal that the UK market is moving towards less carbon intensity. Whilst we applaud this increasing interest in ethical purchases and the income this will mean for developing countries, moves to increase the market for imported food can hardly be said to be, in itself, a move towards climate-friendly activity.

Stern's comments on food are generally in relation to alarming statistics about the predicted effects of climate change on crop yields and food security worldwide.For example, the report states that, ‘Declining crop yields, especially in Africa, could leave hundreds of millions without the ability to produce or purchase sufficient food,’ and, ‘By 2055 subsistence farmers' maize production (the main source of food security) in the Andean countries and Central America could fall by around 15% on average.’

Yet the report has little to say about the types of agricultural production, food-system logistics and food culture that could lead to a permanent cap on greenhouse gas emissions, and help avert the looming threat of droughts and famines predicted to occur with even a modest rise in temperature over the coming years.

Life Cycle Analysis is the favoured scientific method for tracing greenhouse gas emissions of food products from farm to fork (or perhaps more accurately from farm to fart, since waste food is a major source of the powerful greenhouse gas methane). Through such analysis, sources of greenhouse gas in the food system are becoming better known, although the assessment is complex, and consumer advice to guide choices is never straightforward.

Nitrogen fertilisers

Currently, consumers have only simple rules-of-thumb to cut back on their contribution to the seemingly distant ramifications of their everyday food choices. Nitrogen fertilisers are used globally to increase yield from farming. Yet, they do so at significant climate change cost, due to energy used in production, and greenhouse gas emissions of nitrous oxides in use.

You will rarely see nitrogen fertiliser use appearing on the labels of food products. Organic farming excludes their use. In place, organic farmers use clover grown on additional land to produce fertility for the soil.

Such complexities must be considered in policy circles, if we are not to see a rush for productive land to produce biofuels without paying due consideration to the food and fertiliser services that the same land may also be needed for.


Choosing between different modes of transport can make a significant difference to the climate impact of our food choices. For example, we have seen estimates that food transported by air can have between 50 and 177 times greater greenhouse gas emissions than the same weight of produce transported by ship across long distances.

But once again, food miles and methods of transport rarely feature on the label, nor in economic analyses such as the Stern Review. The only time we have seen food transport methods openly declared in the mainstream food market is on the rare occasion when retailers such as M&S and Morrisons show off about the freshness of their fruit or fish by boasting that these are air-freighted.

Should we really be demanding fresh produce from all corners of the globe, which requires immediate transportation to ensure freshness, rather than supporting local markets first, with international markets considered only for less perishable produce? Stern does not say.


A further rule of thumb that Stern might have pointed out is that the increasing consumption of meat is creating an ever-greater burden on the environment. Put shortly, meat production and storage are responsible for high levels of energy use, due to fertilisation and transport of feed crops; destruction of carbon-sinking forests to make way for growing feed crops; energy-intensive production systems, and refrigeration in both transport and storage.

Lower consumption of meat could mean that mixed farms and upland areas would still benefit from being able to provide small amounts of extensively reared local meat. But on meat, Stern has little to say.

The Stern Review has been widely heralded as the 'tipping point' for the UK government's response to climate change. It should surely also be the tipping point for our relationship with the food system, for the benefit of our health, local food economies and the environment.

Useful resources

Click this link to view the Stern report.

Information about greenhouse gas emission hotspots in the food chain and recent research and analysis can be found at the Food Climate Research Network website: