Tesco and carbon labelling: response

In the FCRN newsletter of 9 February 2012 we reported on Tesco’s announcement, as covered by the Guardian and others, that it would no longer be putting carbon labels on its products.  However, since then Tesco has published a letter in the Grocer, clarifying its position.  In summary, while it will no longer be providing consumer-facing labels, Tesco will be continuing with its carbon footprinting activities and is still committed to to reducing the embedded carbon emissions in the products it sells by 30% by 2020, and to finding ways to help customers reduce their carbon footprints by 50% by 2020.

Papers on soil carbon sequestration

A couple of papers by FCRN mailing-list members on soil carbon sequestration: these conclude that the benefits of soil carbon sequestration activites (through the incorporation of organic matter and/or reduced tillage) have been overstated and may distract attention from other priorities, including halting deforestation and improving N use efficiency.   However it is pointed out  that increasing or maintaining the organic C content of soil is almost always beneficial for soil quality and functioning and this is especially so for agricultural soils – ie. sequestration activities represent a ‘no regrets’ activity and are  worth doing anyway.  In addition the authors point out that genuine sequestration and net GHG savings may be achieved through revegetating degraded lands, through the application of compost (where it diverts organic waste from land fill) and there may also be significant benefits arising from the production of biochar.

NB: for an overview of soil carbon sequestration issues, you may want to look at the FCRN’s workshop report on the subject here.

Soil carbon sequestration to mitigate climate change: a critical re-examination to identify the true and the false

Powlson D S, Whitmore A P and Goulding K W T (2011). Soil carbon sequestration to mitigate climate change: a critical re-examination to identify the true and the false, European Journal of Soil Science, 62, 42–55

The term ‘carbon sequestration’ is commonly used to describe any increase in soil organic carbon (SOC) content caused by a change in land management, with the implication that increased soil carbon (C) storage mitigates climate change. However, this is only true if the management practice causes an additional net transfer of C from the atmosphere to land. Limitations of C sequestration for climate change mitigation include the following constraints: (i) the quantity of C stored in soil is finite, (ii) the process is reversible and (iii) even if SOC is increased there may be changes in the fluxes of other greenhouse gases, especially nitrous oxide (N₂O) and methane. Removing land from annual cropping and converting to forest, grassland or perennial crops will remove C from atmospheric CO₂ and genuinely contribute to climate change mitigation. However, indirect effects such as conversion of land elsewhere under native vegetation to agriculture could negate the benefit through increased CO₂ emission. Re-vegetating degraded land, of limited value for food production, avoids this problem. Adding organic materials such as crop residues or animal manure to soil, whilst increasing SOC, generally does not constitute an additional transfer of C from the atmosphere to land, depending on the alternative fate of the residue. Increases in SOC from reduced tillage now appear to be much smaller than previously claimed, at least in temperate regions, and in some situations increased N₂O emission may negate any increase in stored C. The climate change benefit of increased SOC from enhanced crop growth (for example from the use of fertilizers) must be balanced against greenhouse gas emissions associated with manufacture and use of fertilizer. An over-emphasis on the benefits of soil C sequestration may detract from other measures that are at least as effective in combating climate change, including slowing deforestation and increasing efficiency of N use in order to decrease N₂O emissions.

The potential to increase soil carbon stocks through reduced tillage or organicmaterial additions in England and Wales: A case study

Powlson D S, Bhogal A, Chambers B J, Coleman  K, Macdonald A J, Goulding K W T, Whitmore A P (2012). The potential to increase soil carbon stocks through reduced tillage or organicmaterial additions in England and Wales: A case study, Agriculture, Ecosystems and Environment 146 23– 33

Results from the UK were reviewed to quantify the impact on climate change mitigation of soil organic carbon (SOC) stocks as a result of (1) a change from conventional to less intensive tillage and (2) addition of organic materials including farm manures, digested biosolids, cereal straw, green manure and paper crumble. The average annual increase in SOC deriving from reduced tillage was 310 kg C ± 180 kg C ha⁻¹ yr⁻¹. Even this accumulation of C is unlikely to be achieved in the UK and northwest Europe because farmers practice rotational tillage. N2O emissions may increase under reduced tillage, counteracting increases in SOC. Addition of biosolids increased SOC (in kg C ha−¹ yr⁻¹ t⁻¹ dry solids added) by on average 60 ± 20 (farm manures), 180 ± 24 (digested biosolids), 50 ± 15 (cereal straw), 60 ± 10 (green compost) and an estimated 60 (paper crumble). SOC accumulation declines in long-term experiments (>50 yr) with farm manure applications as a new equilibrium is approached. Biosolids are typically already applied to soil, so increases in SOC cannot be regarded as mitigation. Large increases in SOC were deduced for paper crumble (>6 t C ha−1 yr−1) but outweighed by N2O emissions deriving from additional fertiliser. Compost offers genuine potential for mitigation because application replaces disposal to landfill; it also decreases N₂O emission.

The papers can be downloaded here and here (subscription access only).

Australian study

Also, see this related article, which is also fairly downbeat about the potential afforded by zero tillage – it warns that this may have implications for carbon markets:

Maraseni T N and Cockfield G (2011). Does the adoption of zero tillage reduce greenhouse gas emissions? An assessment for the grains industry in Australia. Agricultural Systems 104 (2011) 451–458

The Australian Government has recommended that farmers move from cultivation-based dryland farming to reduced or zero tillage systems. The private benefits could include improvements in yields and a decrease in costs while the public benefits could include a reduction in greenhouse gas (GHG) emissions due to a diminution in the use of heavy machinery. The aim of this study is to estimate and compare total on-farm GHG emissions from conventional and zero tillage systems based on selected grain crop rotations in the Darling Downs region of Queensland, Australia. The value chain was identified, including all inputs, and emissions. In addition, studies of soil carbon sequestration and nitrous oxide emissions under the different cropping systems were reviewed.

The value chain analysis revealed that the net effect on GHG emissions by switching to zero tillage is positive but relatively small. In addition though, the review of the sequestration studies suggests that there might be soil-based emissions that result from zero tillage that are being under-estimated. Therefore, zero tillage may not necessarily reduce overall GHG emissions. This could have major implication on current carbon credits offered from volunteer carbon markets for converting conventional tillage to reduced tillage system.

The paper is available (subscription only) here.

Hospital food waste study

A study by Sonnino and McWillliam investigates food waste in hospitals in Wales. The researchers look at three hospitals and find that up to 60% of the food was thrown away, with levels particularly high in elderly rehabilitation wards.  Unsurprisingly it finds “a strong and direct correlation between the general quality of the hospital meal service and the high amount of food wasted. Specifically, with regard to bulk service, it is clear that too much food is cooked for the number of patients forecast to eat a hot meal and that such number is almost always over-estimated.”

Reference and abstract as follows:

Sonnino R and McWilliam S (2011). Food waste, catering practices and public procurement: A case study of hospital food systems in Wales, Food Policy 36, 6, 823–829

This article aims to address the need for more comprehensive studies on sustainable food systems through a case study of hospital food waste in Wales, UK. Based on a mixed-method research approach that focused on the links between hospital food waste, catering practices and public procurement strategies, the article shows that the hospital meal system, in the case studied, is responsible for overall levels of food waste that greatly exceed the official percentages provided by the Health Board. In addition to showing the theoretical benefits of research that accounts for the complex interrelations between different stages of the food chain, the study raises the need for a more integrated political approach that mobilizes all actors in the food system around a shared vision for sustainable development.

You can download the paper here (subscription access only).

LCA paper incorporating analysis of alternative land uses

This paper looks at the GHG, energy and biodiversity implications of different types of farming systems, taking into account alternative possible uses, and environmental implications of those uses, for any land freed by more intensive production practices (the opportunity cost).  Obviously the findings need to be placed in the context of economic drivers influencing decisions about land use, on the one hand; and any regulations limiting changes in land use on the other.

Reference and abstract as follows:

Tuomisto H L, Hodge I D, Riordan P and Macdonald D W (2012). Comparing energy balances, greenhouse gas balances and biodiversity impacts of contrasting farming systems with alternative land uses, Agricultural Systems 108 (2012) 42–49

Life cycle assessment (LCA) is commonly used for comparing environmental impacts of contrasting farming systems. However, the interpretation of agricultural LCA studies may be flawed when the alternative land use options are not properly taken into account. This study compared energy and greenhouse gas (GHG) balances and biodiversity impacts of different farming systems by using LCA accompanied by an assessment of alternative land uses. Farm area and food product output were set equal across all of the farm models, and any land remaining available after the food crop production requirement had been met was assumed to be used for other purposes. Three different management options for that land area were compared: Miscanthus energy crop production, managed forest and natural forest. The results illustrate the significance of taking into account the alternative land use options and suggest that integrated farming systems have potential to improve the energy and GHG balances and biodiversity compared to both organic and conventional systems. Sensitivity analysis shows that the models are most sensitive for crop and biogas yields and for the nitrous oxide emission factors. This paper provides an approach that can be further developed for identifying land management systems that optimize food production and environmental benefits.

The different farm types are characterised as follows:

1. Organic farm without biogas production (O). The grass clover (GC), cover crop (CC) and crop residues (CR) were incorporated into the soil. Ploughing was used.
2. Organic farm with biogas production (OB). Otherwise similar than O, but the GC, CC and CR (straw of wheat and bean crops) were harvested for biogas production and the digestate was spread to potatoes, winter wheat and spring barley. Ploughing was used.
3. Conventional farm (C). Produced potatoes, winter wheat, spring  beans and spring barley using mineral fertilizers and nonorganic pesticides. The crop rotation did not include GC or CC, and biogas was not produced. Ploughing was used. Crop rotation consisted of potatoes, winter wheat, spring beans and spring barley.
4. Integrated farm (IF). The crop rotation and biogas production were similar to the OB system, but non-organic pesticides were applied. Ploughing was used.
5. Integrated Special (IFS). As IF but instead of GC municipal biowaste was used as a fertilizer. Non-organic pesticides and no tillage were used. Crop rotation consisted of potatoes, winter wheat, spring beans and spring barley.

 
Conclusions:

“The results clearly illustrate the importance of taking into account the alternative land use options when LCA is used for comparing impacts of different farming systems. Even though the conventional systems had the highest energy inputs and GHG emissions per food product output, the whole farm energy and GHG balances were far more favourable for the conventional systems compared to the organic systems once the availability of extra land was taken into account. The results also suggest that integrated farming systems that use the best practices for producing high yields while using environmentally beneficial farming practices can lead to more favourable whole farm energy and GHG balances and the lowest negative impacts on biodiversity compared to organic and conventional systems. This paper provides an approach that can be further developed for identifying land management systems that optimize food production and environmental impacts. More research is needed for studying the wider environmental impacts of the different farming practices, for developing and testing technologies that improve the sustainability of farming and for determining their comparative financial viability.”

LCA-FOOD 2012: deadline extended for abstract submissions

The deadline for abstract submissions to the LCA Food 2012 conference has been extended to February 24.  For more information see here or here.

Environment Group, Policy Studies Institute: jobs available

Research Fellow (full time) and Research Associate (0.6 FTE fixed term to end December 2012)

The Environment Group at Policy Studies Institute (PSI) is an interdisciplinary research team operating at the interface of research and policy. Its aim is to generate evidence that informs and shapes the direction of environmental policy.

It is expanding its research team and wishes to appoint a full-time Research Fellow and a part time Research Associate.  The roles will involve conducting and disseminating policy-relevant, environment-related research on a range of projects and contributing to the work of the Defra-funded Sustainable Development Research Network (SDRN), which PSI coordinates.

Candidates should have research experience, ideally in a range of qualitative and/or quantitative research methods and be knowledgeable about environmental policy issues and systems. An ability to deal confidently with a wide range of stakeholders will be essential. Candidates will have a good first degree in a relevant discipline, while a post-graduate qualification and/or relevant work experience are also desirable.

For more information and to apply go to the University of Westminster website here, (Research Fellow, ref 50000135, and Research Associate, ref 50011088). Details of PSI can be found at www.psi.org.uk.

The closing date for applications is 5th March 2012 and interviews are likely to be held on 19th or 20th March 2012.  Please note CVs in isolation, or incomplete application forms will not be accepted.

Co-operative group reports on ethical progress

The Cooperative reports on progress in meeting the targets set out a year ago in its 2011 Ethical Plan. It reports that:

• Operational greenhouse gas emissions have been reduced by  35%, and water consumption is down by 20%
• £700 million has been lent to green energy projects
• Pressure groups have ranked The Co-operative as leader in areas such as pesticides, palm oil, sustainable fish and forest stewardship
• A million new customer members have joined
• 10,000 community initiatives have been supported by Co-op staff during the year
• 700 co-operative enterprises have been helped 70% of developing world products that can be Fairtrade will be Fairtrade by the of end March

The Co-op has now set additional targets as follows:

• Operational greenhouse gas emissions will be reduced by 50% by 2020, and water consumption will be reduced by 30% by 2014
• £17m will be invested in support of co-operative development
• The number of schools active in its Green schools Revolution will be doubled to 6,000
• To improve the safety of Britain’s roads, young drivers will be rewarded with premium discounts worth £20m
• A new campaign will be launched with Oxfam to champion small-holder farmers and co-operatives, and the role they can play in feeding the world sustainably
• 30,000 loans to entrepreneurs in the developing world will be facilitated by the year end

You can download the press release here. For more about the new Ethical Plan see here.