Author: Martin Bowman

Feedback’s response to the ADBA’s article ‘Why you MUST invest in anaerobic digestion and biogas to build back greener’

6th Nov 20 by Martin Bowman, Senior Policy and Campaign Manager

Feedback provides some clarity and accuracy on our research findings on AD.

Feedback welcome the ADBA’s response to our Executive Director’s recent article in Responsible Investor – however, since the ADBA misrepresent our view and the issues, we hope that this response provides some clarity. For more info, read our report on AD.

A summary of Feedback’s advice to investors

Don’t invest in:

  • AD plants which run on bioenergy crops like maize or grass – even if these are co-digested
  • AD plants built on newly built or newly expanded intensive livestock farms
  • AD plants which lower the costs of animal waste disposal for intensive livestock farms
  • AD plants which process food waste edible to humans or animals
  • AD plants which charge little or nothing for waste disposal or actively pay for wastes, and thus disincentivise waste prevention

Do invest in:

  • AD plants which digest sewage feedstocks
  • AD plants which process only manures and slurries on smaller-scale more sustainable livestock farms
  • AD plants which take on unavoidable food waste which is not edible to humans or animals
  • AD plants which charge higher gate fees to take on food wastes or animal slurries


First, the points on which we agree: AD does have some role in a sustainable future, as a last-resort waste management option – as we argue in our report, there is a ‘sustainable niche’ for AD. AD is certainly better than landfill and incineration of food waste, and is preferable to open storage of manure and slurries – practices which should be heavily taxed and banned as soon as possible. To be clear, this will require some growth in the AD industry, and investment to this end – so it is sometimes sustainable to invest in AD, within limits and in some specific situations. We also agree that sewage treatment by AD is part of this sustainable niche. ADBA’s false claim that Feedback assume AD can only be used to treat food waste is misplaced – our report and the Life Cycle Assessment (LCA) study on which it is based, examine bioenergy crops, manure and slurries too.

However, crucially we model two scenarios: the “industry driven AD” scenario in line with ADBA’s ambitions for AD industry growth, and the “climate optimised AD” scenario where environmentally preferable alternative uses for AD feedstocks are maximized (like food waste prevention) with remaining feedstocks used for AD. In the climate-optimised scenario, we model no bioenergy crops and about a third less food waste going to AD, and additionally we model a context where meat production (and thus availability of manure and slurries) is roughly halved – but all available slurries go to AD in both scenarios. The LCA found that the climate optimised scenario resulted in over double the emissions savings, as well as generating more energy (generated by solar PV on land previously used for bioenergy crops) and significantly higher food production on spared cropland.

ADBA’s presentation of AD as a “win-win-win-win” solution is a simplistic fantasy, although not a surprising stance to take for a body set up to promote the AD industry. Our ground-breaking LCA study, completed in collaboration with academic experts at Bangor University, shows a far more complex and nuanced picture, with some serious limitations to AD. Below, we highlight four key problems:

The first problem is that, as the ADBA acknowledge, AD is far less effective than waste prevention. In fact, preventing food waste results in 9 times more emissions savings than sending it to AD, and if trees are planted on the spared grassland, about 40 times more. The ADBA also often ignore animal feed – our LCA found that sending food waste to animal feed saves 3 times more emissions than sending it to AD. This makes food waste prevention, and using food waste as animal feed, far more effective green investments – and means that only unavoidable food waste inedible to both humans and animals should be sent to AD. Within the current legal framework, there is plenty of scope to increase the processing of food waste like bread for animal feeds – and EU-funded research found that it is possible to feed food waste containing meat to pigs and chickens safely, if EU law is reformed to allow this in a safely regulated fashion. When it comes to manures and slurries, these wastes can be prevented too – through shifts from meat to plant-based diets. For instance, switching from pig meat to a plant-based protein alternative such as tofu results in a 74% reduction in emissions and 80% in land use – land which can then be used for tree planting to offset emissions even further. The emissions savings from sending slurries to AD are far smaller in comparison – so investing in plant-based alternatives to meat would be a far greener investment, from pulses and beans to plant-based burgers and milks. Investors looking to green their portfolios should aim to support dietary shifts as a priority, with AD only used to mitigate the emissions of a smaller, more sustainable livestock sector.

The second problem is that high subsidies to AD create perverse incentives, sometimes actively impeding the better waste prevention alternatives mentioned above. It is completely disingenuous of the ADBA to claim that they are not advocating for high subsidies locked in for decades – their own report clearly advises that AD subsidies are returned to the very high levels of 2011-15, that large-scale AD is subsidised at the same high levels as small-scale plants, and that these be guaranteed for decades into the future. In Northern Ireland, AD subsidies at a similar high level to those advocated by the ADBA were explicitly designed as a means to support an explosion in the size of the country’s intensive livestock industry. Through reducing the industry’s waste disposal costs (even paying for their waste), enabling sites to gain planning permission and bypass environmental regulations, highly subsidised AD plants actually helped expand the polluting industry it was meant to be reducing the environmental effects of. In the case of food waste too, testimonies to a House of Lords enquiry complained that high AD subsidies created perverse incentives to send edible food to AD rather than ensure it is eaten, and Feedback has found many other instances of such complaints. In one case, Feedback’s investigations found an AD plant in a port that in a single day was processing an estimated 60,000 cucumbers, 10,000 figs, 4,000 cabbages and many other foods – which all appeared edible. In this context of distorting high subsidies, investments in some AD plants may thus actively prevent far more sustainable alternatives. The better way to make AD plants financially sustainable without creating these perverse incentives is to tax or ban worse alternatives to AD, such as incineration, landfill, and open manure storage, thus pushing up the supply of wastes to AD and gate fees they can charge for collection.

The third problem is that AD’s emissions mitigation potential significantly declines over time. This is a big problem, since AD plants often take decades of highly subsidised operation to break even on their high up-front costs. The reason for the decline is that as society decarbonises, the emissions that AD currently mitigates are often avoided by other means – for instance, as the electricity grid shifts to renewables, heat and transport are electrified, landfill and open manure storage are banned, AD begins to compare less and less favourably with alternatives. Our study found that some AD feedstocks like grass even begin to have a negative rather than positive environmental impact in a net zero context. This means that the green credentials of investments in AD will decline significantly over time. In comparison, food waste prevention, tree planting, dietary change and solar PV consistently far outperform AD in future decarbonisation contexts (see our report for more detail on this).

The final problem with AD is that, although the AD industry claim that they only want “unavoidable” wastes to go to AD, they have a strong incentive to downplay how much waste is “avoidable” to maximize their growth. The ADBA nowhere in its report mentions dietary shifts away from meat as an option and only currently support the UK’s unambitious voluntary targets on food waste, which pledge only a 24% reduction in post-farmgate food waste between 2015 and 2030. A 50% reduction in UK meat consumption, a genuine 50% reduction in UK food waste from farm to fork through ambitious regulation, and tree planting on the millions of hectares of land that would be spared by these measures, could together mean that UK agriculture could be net carbon negative by 2040 without recourse to BECCS. The AD industry is eager portray agriculture as “difficult to decarbonise” because it actively sidelines these more ambitious alternatives.


*Using 2007 as a baseline year, excluding inedible food waste, using per capita figures which also use a 2007 baseline year.

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Let’s lay the debate to rest

14th Jun 16 by Martin Bowman

It might well make sense to turn sewage sludge or manure into energy, but using food waste to make biogas through anaerobic digestion is a different kettle of fish. In short: the energy and resources required to grow, process, package and transport food that ends up wasted can never be recovered through anaerobic digestion.

The Pig Idea continues to advocate the environmental and financial benefits of repurposing food waste to feed livestock. It is important to note that on the subject of feeding pigs, we’re not talking about the kind of supermarket or manufacturing surplus that can go to food banks and feed people, but rather about what most people really would consider waste: restaurant left-overs, plate scrapings that go into your food waste caddy, or manufacturing by-products that have no other purpose.

New Research

In the most comprehensive study to date on the issue, researchers at Cambridge University conclude that turning this kind of food waste into pig feed has significantly more environmental benefit than biogas or composting.  Pig feed – produced in well-regulated, sophisticated waste to feed conversion systems in South Korea – was compared to biogas and compost in terms of 14 health and environmental impact indicators, and pig feed did better than both biogas and compost in all but two:




 From Salemdeeb, zu Ermgassen et al. 2016.

The reason the results are so clear-cut is that the study accounts for reduced demand for soya and other virgin crop ingredients of conventional feed as it is replaced with food waste-based feed. Currently, 88% of UK soya is imported from Brazil where soya production has devastating consequences on biodiverse eco-systems such as savannahs and the Amazon rainforest.

Composting and anaerobic digestion have disproportionate impacts through eutrophication (water pollution caused by a harmful excess of nutrients), environmental toxicity (eg heavy metals) and acidification. With regard to global warming potential, wet pig feed also scores better than biogas and compost. And in spite of the extra energy needed to dry food waste, dry feed still beats compost too.

Most industrial pig farms in the UK currently use dried feeds; wet feeding is more common in other EU countries, such as the Netherlands, where it is favoured because it permits the use of wet agricultural wastes, such as distillery wastes or beet tails and because of reported nutritional benefits of wet feeding. Dry feed or wet is still open for debate, but what is certain is that converting unavoidable food waste into pig feed makes more sense than ever.

We need to challenge any policy or subsidy that supports food waste diversion to biogas in such a way that there is no incentive to avoid waste in the first place. And since Salemdeeb and zu Ermgassen at Cambridge have removed all doubt on the greater benefits of converting unavoidable food waste to pig feed instead of biogas and compost, the path forward for unavoidable waste is clear. So let’s lay that debate to rest once and for all, and concentrate on setting up the right regulations and systems to replicate the South Korean and Japanese examples safely in the UK and Europe.


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New WRAP report shows large opportunities for supermarkets to reduce surplus where possible and manage unavoidable surplus more efficiently

18th May 16 by Martin Bowman
Without great Feedback volunteers these strawberries would have gone to waste.
Without great Feedback volunteers these strawberries would have gone to waste.

A new study published today (17 May 2016) by the Waste and Resources Action Programme concludes that over a million tonnes of food wasted by UK manufacturers and retailers, worth £1.9bn, is avoidable.

Feedback welcomes this new report as it provides a more granular picture of the amount and types of food wasted in the retail and manufacturing sector. It also presents significant economic opportunities in food waste reduction waiting to be seized by avoiding surplus in the first place, redistributing to charities ,and using food not fit for human consumption for livestock feed.

WRAP’s findings are not only significant in terms of the total figures – over half of the supermarkets and food producers’ waste is avoidable – but because they shed light on individual food categories. It is notable that so much of supermarkets’ avoidable food waste is meat, poultry, fish, and dairy – by far the most carbon-intensive food products on supermarkets’ shelves.

The report also shows that over 10% of supermarket waste could be rescued by food redistribution charities like Fareshare and Foodcycle, which would represent a four-fold increase in food redistribution, compared to the current suboptimal use of total surplus. This increase would equal at least 360 million meals per year.

Getting the full picture of the UK’s industry food waste

Nevertheless, the data published today suggesting that the retail sector is the most efficient part of the supply chain still give an incomplete picture of the food wasted in the UK today. The figures do not include the substantial amounts of food wasted further up the supermarket supply chains on farms and in packhouses. It also does not consider waste occurring in overseas supply chains, which happens as a direct result of buying decisions of the UK’s supermarkets.

Feedback’s Gleaning Network works with farmers across the UK to salvage surplus produce and donate it to charities like Fareshare. Our work with these farmers has shown us just how wasteful supermarkets can really be outside of their own stores. Supermarkets drive high farm level food waste by imposing strict cosmetic specifications, cancelling orders at the last minute, and making order increases that force farmers to hedge by consistently over-producing.

Our investigative work abroad via our Stop Dumping campaign, from Kenya to Guatemala and Peru, shows an even bleaker picture, where supermarket policies cause high levels of food waste for small- and medium-plot farmers. The UK is viewed across the world as the most difficult country to supply to because of its supermarkets’ strict cosmetic specifications.

WRAP have previously estimated domestic agricultural food waste to stand at 3 million tonnes, and waste incurred by farmers and exporters abroad delivering food for UK markets at 4 million tonnes. While these figures are provisional estimates and a lot more research is needed, it is important to consider them alongside the 1.9 million tonne figure calculated in the report released today.

We cannot ignore waste occurring outside of supermarkets’ four walls, whether in the UK or abroad. We therefore welcome WRAP’s initiative to establish a working group that will attempt to quantify on farm food waste levels and increase collaboration between retailers and farmers to tackle the problem and look forward to seeing ambitious action by the industry as a result.

The opportunities in tackling farmer level waste are also substantial and easy to act on. Already, some retailers in the UK and Europe have started to respond to public pressure and have taken measures to address food waste in their supply chains. For example, in response to Feedback’s years of investigations and campaigning, Tesco recently desisted their wasteful policy of trimming beans. Likewise, in response to Feedback’s challenges, Tesco and Carrefour audited and significantly reduced waste in their banana supply chains. Other retailers have also started to slowly relax their policies on cosmetic standards.

However, if the UK food industry is to achieve the ambitious targets set by the Sustainable Development goal of halving food waste by 2030, we need to see much more ambitious steps by UK retailers to address food waste in their domestic and overseas supply chains and tangible measures of much larger scale of what we have seen today.

Opportunities to use surplus food for animal feed

Importantly, WRAP’s findings also show that unavoidable food surplus which can be diverted to animal feed could increase by 20%. We welcome and applaud WRAP’s commitment to work with the FSA and enforcement bodies to encourage businesses to divert more food surplus to animal feed. The guidance published today alongside the report is an important step to support manufacturers and retailers in doing so.

During WWII the government actively promoted waste feeding pigs.
During WWII the government actively promoted waste feeding pigs.

We also welcome WRAP’s continued emphasis on diverting unavoidable food surplus that is no longer fit for human consumption to animal feed, recognising its significantly greater environmental benefits as opposed to anaerobic digestion.  It is crucial that UK and EU authorities remove perverse incentives on anaerobic digestion to ensure this potential increase of 20% can be achieved.

Furthermore, given the plight of EU livestock farmers and the EU feed protein deficit, the findings on meat and fish waste reinforce the need for the re-legalisation of feeding unavoidable surplus meat and fish to omnivorous livestock, such as chickens and pigs.

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how food waste can help

3rd May 16 by Martin Bowman

Save Kitchen Waste to Feed the pigsLast week 400 pigs were found starved to death in the Netherlands as it appears their bankrupt farmer had given up on them. This is just one example of many, alarming animal welfare and farmer organisations alike.

In the first three months of 2016 alone, five Dutch pig farmers went bankrupt, almost as much as the total figure for 2015. Earlier this year, agriculture experts warned that Britain’s pig farmers are also braced for a horrendous year, as a glut of pork on the global markets sends prices plunging.

In addition to the impact on farmers themselves, animal welfare suffers too. The need to keep costs down results in terribly overcrowded and stressful conditions which in turn lead to antibiotics overuse.

The cost of feed is a major issue. In 2015, feed made up 56% of total expense for pig farmers in the UK (and as much as 65% in Ireland). At the same time, our friends at the Japan Food Ecology Centre produce nutritious and safe pig feed from food waste at half the cost of conventional feed.

What more incentive do we need to urgently create centralised industrial treatment systems to safely convert kitchen left-overs to pig feed? These systems need to be underpinned by sound legislation guaranteeing the microbiological safety of the resulting feed, and incentives to ensure the enormous environmental benefits are realised too.

At Feedback, together with our research partners of the REFRESH programme we are working hard to clarify existing guidance, so that more currently permissible surplus food and by-products replace expensive virgin feed crops like soya.

We are also furthering collaborations with scientists to confirm the exact treatment specifications to guarantee the safety of feed made from catering waste. We hope that the plight of farmers and pigs alike will encourage governments and the industry to urgently prioritise this work themselves. We’d be all too happy to join forces.

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Gleaning roundup 2014

26th Nov 14 by Martin Bowman

Apple gleaning - MartinGreetings glorious gleaners! It’s been a really busy time for the Gleaning Network, as the past few months have been peak harvesting periods! We’ve been harvesting tonnes of food that would otherwise have gone to waste on farms for charity.



Cauliflower gleaning 4In 2014, we’ve gleaned 54 tonnes of delicious fruit and veg across 31 gleaning days with 340 volunteers, in Bristol, Manchester, Sussex, Cambridgeshire and Kent. That’s 675,000 portions of fruit and veg for the hungry and food insecure of the UK, so huge congrats to all our volunteers.



Apple gleaning10Some of the highlights have been our debut gleaning day in Bristol, a huge sweetcorn glean in Sussex, a colossal brassica glean in Kent, our first gleans of onions and potatoes in Cambridgeshire, a great cauli and potato glean in Manchester, and these beautiful wonky squash.



2014 11 07 Pumpkin Mini Glean 35x 2014 11 07 Pumpkin Mini Glean 28x








chris-king-photography_the-gleaning-network_SOCIAL-MEDIA-11We’ve saved apples that were the “wrong” colour and size for supermarkets, cauliflowers that couldn’t be sold because of the Russian embargo and a rush of cheap imports, onions which fell through the gaps in the harvester because they were too small, cabbages which were rejected by supermarkets for being a little pigeon pecked, and more…


FareShare depot2We’ve donated to FareShare, CFE, the Matthew Tree Project in Bristol, The Ferry Project in Cambridgeshire, Food For All in London, and others, as well as selling some produce to social enterprises Community Shop, Rubies in the Rubble and Snact to raise money for our charitable gleaning.







10389435_583199578446542_7544783243091462236_nWe’ve also been busy spreading gleaning around Europe, with Gleaning Network EU! Gleaning has already kicked off in Belgium, Poland, Spain, France and Greece.





Gleaning OaklandFinally, gleaning days tied in with Feeding the 5000 events around the world have been sprouting up too, including  gleaning days in Oakland (US), North Carolina and Barcelona.





We’ve also had coverage in Kent Voice, and have some very exciting news upcoming, where we’ll be featured on the TV programme of a prominent celebrity chef (ooooh… watch this space).

If you’re interested in volunteering, and you’d like us to let you know when there’s a gleaning day coming up near you, please sign up to our gleaning list!

So peace and potatoes, over and sprout, thanks shallot, and other than a few last gleans of the year, we’ll see you in the Spring!

Apples gleaning14

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