Sustainability and Biodiversity
Achieving net zero
The Governing Body of the College has agreed to adopt 2035 as its target date for achieving net zero carbon and biodiversity net gain in the College and across the College estates.
Sustainability Forum
The Governing Body has also created a Sustainability Forum to help develop initiatives and meet the challenges as it moves towards its targets.
Chaired by the Warden, Professor Jennifer Payne, and reporting to the Governing Body, the Forum meets termly to work on the College Sustainability Strategy which can be found here.
The Forum is looking at all aspects of the College’s sustainability planning both in Oxford, in its investment portfolio, and in the College’s rural estates, and will be building on what has already been achieved and planned by the College in promoting sustainability and biodiversity.
A Sustainability Duty has been introduced (Bylaw VI.39A) into the College’s decision-making processes to ensure that due regard is had to the College’s Sustainability and Biodiversity Commitments. Decisions and recommendations must include both a statement that due regard has been had to the Sustainability and Biodiversity Commitments and a reasonable assessment of the positive or negative effect of a decision or recommendation on achieving them.
Measuring what we do
The College has begun reporting its Scope 1 and Scope 2 carbon emissions in the Annual Report and Financial Statement. The College will also use the College Carbon Emissions Toolkit. Merton’s Colleges Sustainability Officer worked with fellow sustainability leads to build a colleges carbon emissions toolkit to help colleges to calculate their emissions moving forward. This will mean colleges are able to calculate their emissions in a uniform way for the same period. The tool was created for the 2024-2025 academic year, aligning with University reporting, using the relative DEFRA carbon emissions conversion factors.
The tool currently calculates Scope 1, 2 and elements of Scope 3 including water, waste, transmission and distribution losses (T&D) and Well To Tank (WTT) as this is information readily available to colleges. Categories for Scope 3 will be added to the tool in the future.
Merton has used the services of a specialist energy surveyor to audit the College estate in terms of carbon, natural capital and biodiversity - this was in conjunction with a University research project run by the Oxford Partnership for Operationalising the Conservation Hierarchy. We have also worked with a specialist external energy advisor with expertise in historic buildings to assist in reviewing our carbon footprint, identifying opportunities for carbon reduction, developing policies and increasing college-wide awareness through improved reporting and communication.
One early outcome has been the replacement of many of our manually-read electricity meters with Automated Meter Reading (AMR) equivalents, meaning energy consumption is now being accurately recorded with consumption data available via a web portal.
Making our buildings more energy-efficient
Merton has an ongoing programme to replace baths with shower facilities in student and Fellows’ accommodation, and we will be fitting a high-efficiency Megaflo hot water storage system as part of our refurbishment programme.
The TS Eliot theatre building employs rainwater harvesting, makes extensive use of natural lighting, and has an adiabatic heating and cooling system in the main theatre hall; the building has been awarded a BREEAM Excellent Rating. We use the cloud-based platform eco-sync, which allows room-by-room control of heating and will synchronise room bookings with heating control; this has resulted in a 20% reduction in gas use.
Switching to electric
We have significantly reduced energy usage in our kitchens through the replacement of gas hobs with electric induction hobs.
We have upgraded washing machines and fridges to A+++ standard, resulting in energy savings due to reduced power and water requirements.
Traditional incandescent lighting is being replaced with LED equivalents in both college accommodation and the Chapel. Lighting controls and timers have also been fitted.
Reducing consumption
We always look to install or upgrade draught-proofing and insulation in our buildings when they are being refurbished: two recent projects involved the installation of insulated exterior cladding and double-glazed windows, both effective means of minimising heat loss. Our multi-year refurbishment of student rooms has involved replacing and upgrading windows, installing high efficiency electric heating, LED lighting and centrally stored hot water systems. The combination of installing high efficiency glazing and low energy, controllable heating has been very beneficial. Having large centralised hot water systems as opposed to local point-of-use heaters has also made buildings more energy efficient and controllable.
We have installed a voltage optimiser/step-down transformer, reducing energy consumption by 15%.
The installation of modern Thermostatic Radiator Valves (TRVs) has allowed us to improve thermal efficiency.
All toilet cisterns have water-saving devices fitted. The main plate-washing machine in our kitchens has a recycle facility to reduce water consumption.
Recycling and reducing waste
Recycling is carried out widely across the College, to minimise waste being taken off-site. We provide separated recycling bins in accommodation, offices and communal spaces. Confidential waste paper is shredded and recycled. We recycle printer cartridges, pens, and batteries. Garden waste is composted and reused.
Digitising processes, for example providing committee and meeting papers in electronic format, has successfully helped us to reduce our paper waste, as well as reducing the administrative load on staff.
We have reduced single-use plastics in packaging, and introduced 100%-recyclable cups for all our in-house coffee facilities.
Cutting food waste
We run a food waste recycling scheme from our main kitchens, and send food waste to a local anaerobic digestion plant (Cassington AD facility) where it is converted into green energy and a bio-fertilizer which Oxfordshire County Council uses on its gardens, green spaces & parks. This initiative is supported through the provision of food caddies and signage in our dining hall, as well as in kitchens in student accommodation.
Most meals are pre-booked to avoid waste and we have portion control at the food servery. Where possible in accordance with safety requirements, the Kitchens team recycle leftover food in other meals.
Food plate waste is measured at the end of every service allowing us monitor plate waste to make adjustments to reduce food waste.
Sustainable sourcing
Our Kitchens team, led by Head Chef Simon Crawshaw, make great efforts to ensure that the food we serve is sustainably sourced: this includes using local seasonal suppliers, Fairtrade/Rainforest Alliance suppliers for coffee, MSC-certified fish (mainly caught by locally owned & crewed day boats - we never buy fish from factory trawlers - and bought from Brixham Fish Market in Devon), and ethical sources for palm oil and many other products.
We buy as many ‘in season’ British fruits & vegetables as we can. The eggs we use are all free range, and come from Mayfield Farm – only 15 miles from the College. We buy much of our meat from Aubrey Allen Butchers, recent winners of the National Meat Buyer of the Year award for ‘Ethical Sourcing & Animal Welfare’ and plastic-free business champions. Our genuinely free range pork is Blythburgh Pork from St Margaret’s Farm in Suffolk. Most of our poultry comes from Robert Caldecott who runs a third-generation farming business in Worcestershire producing high welfare free range chicken and turkey.
Promoting sustainability
We have a Green Impact group which involves Fellows, staff and students in promoting sustainably focused work. The group meet on a termly basis and report on their activities at staff briefings. Their work has been recognised with the Oxford Sustainability Green Impact Gold Award.
Merton is part of the Conference of Colleges Environmental Sustainability working group, which published its report on existing college sustainability initiatives in May; we continue to work with other colleges across Oxford to share details of existing and planned sustainability initiatives.
Investing sustainably
“As part of our focus on sustainability, in 2020, we moved the entirety of our developed market listed equity portfolio to an ESG tilted tracker. The change reduced the carbon emissions intensity of the portfolio by over 40%.”
Charles Alexander, Finance Bursar
In 2020, the College sold all of its developed market listed equity holdings in L&G’s index funds and reinvested the proceeds in L&G’s Future World ESG Developed Market Index Fund. This move has significantly reduced the carbon emissions intensity and carbon reserves intensity of the College’s listed equity holdings, and ensured that the College’s listed equity investments have no exposure to pure play coal miners, manufacturers of controversial weapons and companies in perennial breach of the UN Global Compact. The College has also now switched its emerging markets listed equity holdings in L&G’s index funds to the L&G’s Future World version, thereby completing the process begun in 2020 to move all is listed equity holdings to ESG index funds.
In early 2024, the College announced that it is part of a coalition of sixty leading institutions and trusts in UK Higher Education which was created with the purpose of launching a market for cash products that do not contribute to the financing of fossil fuel expansion.
Biodiversity and Sustainability across the College's estates
"Completing the natural capital and biodiversity audit of the College Estates was an important first step in supporting the College’s carbon strategy and we are now developing the road map to net zero. We actively review the effects on overall carbon production of changes to our estate management or the introduction of new projects such as renewable energy schemes.. We are keen to support our farm tenants to build resilience and improve biodiversity by taking forward projects such as hedge and tree planting and moving towards more regenerative farming techniques."
Sophie Tidy, Land Agent
In 2021, the College completed a natural capital and biodiversity audit of its external estates. This provided a baseline on the carbon footprint and biodiversity throughout the College’s estate, based on the existing use and occupancy. An updated audit is due to take place in 2026 and will allow the College to model the effects on overall carbon production of changes to estate management and the introduction of new projects over the last 5 years.
All the College’s rural estates have been reviewed with renewable energy operators to test their suitability for renewable installations. College has entered into 3 Option Agreements to lease land in Surrey for battery storage sites capable of storing between 100-150 megawatts of electricity. Planning permission has been achieved on 2 of the sites to date and these are likely to be operational by 2027/8.
The potential for a solar and wind installation in Northamptonshire and a wind development in Lincolnshire are also being explored.
A 340-acre Oxfordshire farm was surrendered in 2022, and has since been farmed in hand. Intensive arable production has been replaced with land management designed to improve soil organic matter and carbon sequestration, together with biodiversity. A Countryside Stewardship Scheme was entered into from January 2023 and wildflower and legume mixes were drilled from Autumn 2023. The grassland is managed with low inputs and is cut for hay and aftermath grazed by sheep. Soil sampling, a habitat baseline survey and suite of bat, breeding and wintering bird surveys took place over 2022/3 and will be re-visited in 2027 to assess the impact of the change in land management.
A 1,150 acre Leicestershire farm is coming back in hand in September 2026. The applicants’ approaches to sustainable farming practices will be a key part of the decision making on the choice of incoming tenant. All new farm tenancies include soil baselines and drafting to encourage occupiers to improve biodiversity and soil health and reduce carbon production.
We continue to work with our existing farm tenants to enhance the natural capital on the College’s rural estates by encouraging the implementation of regenerative farming techniques as well as hedge planting and tree planting. With the uncertainty of capital grant funding for projects such as hedge planting, College are reviewing how to support farm tenants to undertake these projects, potentially through direct funding where grant funding is not available.
The College Gardens
Under the leadership of Head Gardener Lucille Savin, the College Gardens continue to flourish. Lucille and her team are committed champions of sustainability and biodiversity, placing ecological responsibility at the heart of how the gardens are designed, managed and enjoyed.
From drought-resilient planting schemes to an ever-expanding collection of cacti and succulents inspired by students’ enthusiasm for houseplants, the College Gardens reflect this ethos in practice. Garden waste is composted on site, creating a valuable supply of rich, organic mulch for herbaceous borders and compost for bedding plants, all of which are propagated and grown entirely in-house. Under Lucille’s care, the College Gardens have moved away from any previous reliance on imported compost and bedding plants – a highly resource-intensive industry – towards a sustainable, closed-loop system.
Merton’s gardens have evolved from ornamental spaces into living, sustainably managed landscapes that play a central role in the College’s environmental strategy, student wellbeing, teaching and research, and the stewardship of its living heritage. Designed and cared for with clear ecological intent, the gardens also provide an important forum for engaging students, staff and Fellows in the practice of good environmental stewardship.
This engagement is supported through the delivery of garden tours, interactive workshops and plant give-aways; the installation of nesting boxes for birds, hedgehogs and solitary bees across the College; and the use of interpretation and signage on both the main site and at the College meadows to encourage awareness and participation. The gardens also support student welfare initiatives such as vegetable growing alongside academic research projects, including a recent mistletoe survey.
Together, these initiatives ensure that the College Gardens are not only places of beauty and refuge but living examples of how thoughtful stewardship can support biodiversity, enrich the academic community and shape a more sustainable future for the College.
Since 2020, the Gardens team has been working in partnership with the Thames Valley Wildflower Meadow Restoration Project, to restore two of Merton’s historic city meadows: Great Meadow and Music Meadow. Together, these sites form part of a wider interconnected network of wildflower meadows across Oxford – supporting a multitude of wildlife and providing refuge for plant and animal species that struggle to survive in more intensively managed habitats.
Restoration work began in 2020 and continues through a programme of sustainable, low-input management designed to re-establish species-rich meadow communities. Central to this approach is the introduction of locally sourced ‘green hay’ from a nearby species-rich meadow, combined with seasonal sheep grazing to limit grass dominance and maintain the open conditions in which wildflowers can thrive. A keystone species within the meadow is yellow rattle – Rhinanthus minor – an attractive native plant with bright yellow flowers that semi-parasitises grasses, gradually reducing their vigour and creating space for a wider diversity of wildflowers to establish.
Our annual cycle of meadow management follows a traditional regime informed by a contemporary ecological conscience, intended for biodiversity and long-term resilience. A single hay cut each summer removes that year’s growth and progressively lowers soil fertility, shifting the balance away from grasses and in favour of wildflowers. The wildflower hay (which is more nutritious than simple grass hay) is then used by local farmers to feed their cattle, supporting sustainable agriculture, while subsequent sheep grazing further reduces grass growth and helps press wildflower seed into the soil, creating optimal conditions for germination in the following season.
After years of careful management and observation, the Gardens team is pleased to report a clear increase in both species’ richness and abundance, with new species appearing each year – including the arrival of many native orchids. This diversity is central to the resilience of the meadows, enabling them to respond to unpredictable weather patterns and the wider impacts of climate change. Our meadows also play an important role in carbon sequestration. Species with varying root depths draw carbon deep into the soil – in some cases to over 1.5 metres below ground – where it is locked up whilst the soil is left undisturbed.
Merton’s Meadows also provide a sustainable source of nectar and habitat for bees, butterflies and birds, supporting a wide range of UK pollinators. Alongside these species-rich wildflower communities, a small number of honeybee hives, managed by a local beekeeper, have been introduced as part of the wider meadow landscape.
The meadows also serve as valuable spaces for learning, research and public engagement. Regular summer tours are led by the Gardens team for students and staff, while meandering grass rides allow visitors to explore the meadows throughout the year and experience the diversity of native flora and fauna at close quarters.
The College continues to monitor changes in plant and insect diversity and to enrich both Music Meadow and Great Meadow with additional native species, including cowslip, snake’s-head fritillary and marsh marigold. Through ongoing stewardship, research support and public engagement, Merton’s Meadows demonstrate how sensitively managed landscapes can deliver lasting benefits for biodiversity, climate resilience and the wider academic community.