By Kieran Cooke / Climate News Network

A potato field in Germany. (Topfkiao via Wikimedia Commons)

LONDON — It’s called the Cool Farm Tool (CFT) — an easy-to-use online calculator which helps farmers monitor their emissions of greenhouse gases.

Agriculture accounts for about 15% of total global greenhouse gas emissions, though when fertiliser manufacture and use and the overall food processing sector are included in calculations, that figure is considerably higher.

The land can also act as a vital carbon sink, soaking up or sequestering vast amounts of carbon: when soils are disturbed the carbon is released, adding to greenhouse gases in the atmosphere.

The CFT was initially developed by researchers at the University of Aberdeen in the UK in partnership with Unilever and the Sustainable Food Lab.

Now managed by a group including academics and food manufacturers called the Cool Farm Alliance, the CFT is free for farmers to download.

Various details, including the crops being planted, soil types and pH levels (the relative acidity or alkalinity of the land), are entered into a series of boxes.

Moisture levels, amounts and types of fertiliser used and general management details are also entered, along with information on quantities of diesel and electricity used in the cultivation and storage of crops and the fuel needed to transport goods on and off the farm.

Halving emissions

In 2010 PepsiCo, the drinks and food conglomerate, launched a programme aimed at making its operations more environmentally friendly.

In particular it sought to halve the amount of greenhouse gas emissions and water use arising from production at its Walkers Crisps factory at Leicester in the UK — the largest such plant in the world, producing five million packets of crisps (known as potato chips in the US) every day.

A central part of the PepsiCo project involved encouraging its potato suppliers to farm more sustainably through the use of the CFT and by using other devices to monitor and cut back on water use. New potato varieties with improved yields were also introduced.

Within six years, the goal of halving carbon emissions and achieving a 50% reduction in water use was reached.

“Now we’ve learned to calculate

our carbon emissions far more easily,

we can focus on areas that need improving.”

Spearhead Potatoes, based near Cambridge in the east of England, is one of the UK’s biggest potato companies, and a major supplier to Walkers.

John Addams-Williams, a director at Spearhead, says using the CFT and cutting back on water use has not only resulted in more sustainable farming practices but has also saved on costs.

“The key is to get more out of what you put in — we’re producing more while at the same time we’ve cut our carbon footprint and saved on water use”, he says.

“Now we’ve learned to calculate our carbon emissions far more easily, we can focus on areas that need improving, such as storage, and gaining greater efficiency from our fridge plants.”

The CFT is now being promoted in various parts of the world: its backers say it would be an ideal tool for use by small-scale farmers, for example among coffee growers in Costa Rica.

Hot spots

Sarah Wynn is a consultant at ADAS, the UK’s largest independent provider of environmental and agricultural research.

“The CFT can help identify certain ‘hot spots’ in the growing and production process which account for a substantial amount of emissions”, says Wynn.

“We work alongside farmers and use the tool to target areas for action, such as cutting down on nitrogen use on their land or reducing the amount of greenhouse gas emissions involved in storage, which can be a big contributor to overall emissions: the idea is to look at the whole supply chain from field to factory.”

The Cool Farm Alliance says the CFT not only measures farms’ greenhouse emissions — it also stimulates thinking about management systems and helps develop sustainable plans of action.

Various other versions of the CFT are either in operation or being released soon, including one for measuring livestock emissions, another for calculating the impact of farming on biodiversity, and one for measuring water use.

Kieran Cooke, a founding editor of Climate News Network, is a former foreign correspondent for the BBC and Financial Times. He now focuses on environmental issues.