Bartlett Net Zero: Current status, options and future potentials

1.1    Reducing energy demand

Fyabupi Kalua reported on the prospects for institutional buildings to reduce their energy consumption. UCL currently spends £14 million on energy per year, of which half is due to heating, cooling and ventilating buildings (Sustainable UCL, 2021). Therefore, energy demand reduction not only can assist with reaching net zero but can also enable financial savings.

Data analysis shows that energy use in The Bartlett’s 22 Gordon Street building falls by around 50% during the holiday closure periods at Christmas and Easter. This shows the potential for energy demand reduction at times of low or no occupancy. Further analysis should explore the extent to which building energy consumption tracks occupancy more generally, thereby highlighting whether more responsive building energy performance might deliver further energy savings.

Behavioural changes of users may play a crucial role in delivering energy savings (Tovey and Turner, 2006). Studies in the literature show behavioural measures bringing about energy demand reductions in university campuses in the region of 25-30% (Emeakaroha et. al, 2012; Fabi, et al., 2017; Tovey and Turner, 2006). For this, support and engagement is required from all levels of an institution (Klein et al., 2012). Some studies have shown that providing users with real-time information feedback on their energy uses can have significant effects in motivating more energy efficient behaviours (Emeakaroah et al., 2012; Fabi et al., 2017). 

Retrofitting of buildings can offer significant energy savings. Simple retrofitting strategies such as solar shading, insulation, window glazing and thermal bridging can reduce energy consumption by a third (Gomaa and El- Darwish, 2017). Building energy management strategies, including the optimisation, appropriate sizing and technology choice of HVAC systems, can also deliver significant savings (Erhart et al., 2016). The use of thermal storage could enable energy demand to be drawn at off peak times, which could have synergies with the use of renewable electricity.

Analysis of Bartlett energy consumption data for 2019 shows that the electricity consumption per m2 of Central House was similar to that of 22 Gordon Street, while the heating demand per m2 was about 26% lower in Central House than 22 Gordon Street. This is an interesting result as the latter building recently received a significant retrofit. Possible reasons for the difference could include: different kinds of building uses, with uses being more energy intensive in 22GS; longer hours of building use; differences in building energy management systems and the way they are used. However, it is not only relevant to compare the performance of 22 Gordon Street to other buildings, but also to its own performance pre-retrofit. Further investigation of the data will be needed to achieve further clarity on these issues, and may help to uncover whether further energy savings may be possible across all buildings, through improved building management. For example, the data appears to indicate a substantial increasing in heating demand at 22 Gordon Street in 2019, compared to 2018, which it would be useful to interrogate further. 

The programming and control of heating, ventilation and air conditioning (HVAC) systems can help to optimise building energy use, such as zonal control. The relatively high proportion of energy used across UCL for cooling may indicate that this service is being over-used. There is potential to use existing roof space for solar panels, as well as to incorporate building-integrated renewable energy in new buildings, an example being the PEARL (Person-Environment-Activity Research Laboratory) building. 22 Gordon Street is equipped with rooftop solar panels. Further analysis should review the performance of these, and consider options for further onsite renewable energy production.

2.2    Decarbonising heat

35% of onsite energy use is provided by the district heating network, and Gower Street’s District Heating Network contributes 28% of UCL’s total emissions (Sustainable UCL, 2021). It is of considerable importance therefore to consider how the supply of these networks can be changed as part of the challenge of achieving net zero.

Bipash Paul investigated options for decarbonising UCL’s district heating network, focussing on the potential to recycle waste heat from the London Underground Network. The Underground network includes ventilation shafts for the removal of waste heat. This creates a potential source of heat that could be recovered for other uses. One example is The Bunhill 2 Energy Centre in Islington, which recovers heat from the underground for use in district heating (Celsius, 2020). The Bunhill 2 Energy Centre was a joint collaboration between Islington Council, Transport for London and the Mayor of London (Wilson, 2020). It was funded by Islington Council who own and run this heat network but received numerous grants from the European Union’s CELCIUS projects (Islington Council, n.d.).

In the Bunhill case, warm air passes through a series of air-to-water heat exchangers that recovers nearly 780kW of heat. However, this heat is low-grade and hence, is sent to a heat pump which upgrades the energy by adding 260kW of heat. This heat energy is then ultimately supplied to the established district heating network with a flow temperature of 75°C and return temperature of 55°C. The expected annual heat demand is closely 11,358MWh providing heating to 455 dwellings and to a primary school (Henrique Lagoeiro, et al., 2019). The heat pump is powered by the electricity generated by the two CHP units on-site and the excess heat also adds resilience to the system. Lastly, the system also has a 77.5 m3 thermal store to manage peak demand (Henrique Lagoeiro, et al., 2019).

Paul notes the potential for a similar system to be used as a substitute to the existing heat source in UCL’s district heating network. This is possible due to UCL’s close proximity to the nearest mid-tunnel ventilation shaft in Euston. The shaft is located on Stephenson Way, a small street behind Euston road and on the site of a former UCL building, Wolfson House (The Construction Index, 2019). The shaft is linked to the Northern line tunnel beneath it from where the excess heat can be extracted.

There would be governance challenges to such a scheme, in that it would require collaboration between different actors, likely including Transport for London, Mayor of London, University College London and Camden Council. The scheme would require substantial capital investment, and would likely require the support of a thermal store that is not present within the existing network. 

Paul also considers for a 5th Generation District Heating and Cooling (5GDHC) network. This is a system that combines the heat network to deliver heating and cooling by exchanging thermal energy between buildings with different heat demands. The network consists of two pipes, a warm pipe and a cold pipe which are connected to the buildings on the network. Each building has a heat pump installed within them and generates the required temperature at the point of demand (Interreg North West Europe, 2021). These heat pumps are bi-directional and can thus deliver both heating and cooling power. 

London South Bank University (LSBU) has recently adopted this method to provide heating and cooling for two of its buildings. The network is called the Balanced Energy Network (BEN) and was partially funded by the Department for Business, Energy and Industrial Strategy through the Innovate UK programme. It draws water from the London Aquifer through two 110m boreholes  (Song, et al., 2019). The simultaneous heating and cooling with a thermal store eliminate the need for individual gas boilers that reduces costs. The network enables recycling of thermal energy – heat is rejected from buildings that need cooling and injected into buildings that need heating. The system is also highly efficient as it operates at rather low-temperatures and hence, there are lower thermal losses within the network. 

Both of these solutions present interesting options to make use of existing district heating infrastructures. However, they would nonetheless require some considerable infrastructure investment, for example, both would likely require thermal stores. The first would require partnerships with external actors, such as Camden Council and TfL. Future research in this field could explore the potential of integrating the two solutions within a district heating network. 

2.3    Decarbonising energy supply with green tariffs

Another way of decarbonising the energy we use in buildings is to source the energy from “green” suppliers. This indeed is part of UCL’s planned approach for electricity and gas. UCL currently sources electricity from a “green” tariff, and intends to move towards a direct power-purchasing agreement. UCL also plans to move towards a green tariff gas supplier by 2024.

However, not all green tariffs are as green as each other. Giovanni Manfredi explores the different kinds of green tariff, and what factors should be considered in sourcing green energy in this way. 

Green tariffs are often backed up by the purchase of Guarantee of Origin (GOs) certificates. GOs create the expectation that by purchasing a green tariff, a customer would encourage new investments in renewable energy (Hamburger, 2019). However, that may not be always the case.

A GO is an electronic document which has the sole function of providing proof to a final customer that a given share or quantity of energy was produced from renewable sources. One GO is equivalent to one MWh of electricity or renewable gas generated. Energy producers issue the certificate in an electronic registry. When a buyer purchases the certificate, it is cancelled from the registry. 

Thus, in theory when a customer purchases electricity on a tariff that is backed by GOs (called Renewable Energy Guarantees of Origin, or REGOS, in the UK), they are paying for an equivalent quantity of renewable energy to have been generated at some point.

A key issue is additionality – if the renewable energy would have been generated anyway, without the additional demand created by the customer’s green tariff, then arguably the green tariff is not having any affect. For this reason, some have argued for excluding the already renewable rich Norwegian system from the European GOs market, and for only allowing new plants to produce GOs  (Mulder and Zomer, 2016). After Brexit the situation between the UK and EU markets is still unclear. The current UK position is that they would accept GOs only if the EU would accept REGOs; if GOs are not to be accepted in the UK, then this may solve the oversupply problem (Ofgem, 2021). 

Another aspect of the additionality problem is that if a supplier already has a mixed portfolio of green and grey generation sources, then an individual choosing a green tariff may make no difference to the supplier’s overall portfolio – the supplier simply allocates some of their existing green energy to the green tariff customer, rendering the energy supplied to the standard tariff customers slightly less green, with no overall change.

Another issue is that the separation of the REGO market from the physical trade market, can allow REGOs to be sold “unbundled” from the renewable energy that originally generated them. When the supply of REGOs is plentiful in relation to demand, their price can fall to very low levels. For example, Castellano et al. (2017) found that in Germany the premium price that consumers paid suppliers were on average 20.76€/MWh, while the price of the GOs on the market was 0.43€/MWh. When this happens, suppliers having sourced their customers’ energy from fossil fuel generators can purchase sufficient REGOs to cover their obligation to green tariff holders, but at a very low cost that is not commensurate with the investment required to fund new renewables. An independent report for the Climate Change Committee (Wills, 2020) notes that Ofgem could identify only three suppliers whose green tariffs could be considered truly additional due to direct matching of consumer demand to renewable supply; whereas for the most part “we do not have sufficient evidence that existing renewable tariffs provide additional environmental benefit beyond existing renewable generation” (Ofgem, 2018).

Increasing transparency on the part of suppliers as to how the premium price of the green tariff is utilized, would help customers to understand if their choices are really having an impact on new investments (Carbon Trust, 2019; Hast et al., 2015). Some suppliers do claim to reinvest the bill money directly in new renewable energy infrastructures, or to support renewable energy project financing (Home, 2021; ECOHZ, 2021). 

The consumer can also collect information regarding the supplier’s annual fuel mix, whether it is all green or a mix of grey and green sources (Carbon Trust, 2019). If suppliers have a fuel mix containing both grey and green electricity, they may supply a new green tariff simply through reallocation, as described above; whereas a green tariff from a supplier that supplies only green energy, is more likely to support commensurate new investment. 

Customers can also source energy from their own renewable installations, or purchase directly from renewable generators in a power purchase agreement (PPA), where the REGO is “bundled” together with the supplied electricity (Carbon Trust, 2019; Concept Energy, 2022). An independent report for the Climate Change Committee (Wills, 2020) finds that the PPA approach is much more likely to maximise “decarbonisation of the electricity grid at a systemic level” than most green tariffs.  

As the Bartlett’s buildings currently have gas as well as electricity demand, it is also relevant to consider whether the purchasing of green gas supplies can contribute to decarbonising our energy consumption. Green gas includes biogas (CH4), biomethane (CH4), and hydrogen (H2). Biomethane is sometimes distinguished from biogas as being purer, containing at least 97% of CH4 – however, the difference is not universally accepted, and some use biogas and biomethane interchangeably (Long and Murphy, 2019). In 2018 in Europe there were 610 Biomethane operating plants, with a production of 22,787 GWh, which was 0.5% of the total natural gas consumption (Herbes et al., 2021).  The UK represent the second biggest player with 85 upgrading plants after Germany with 194 (Schmid et al., 2019).

EU regulations also enable a GO scheme for green gas. Because there is greater potential to physically track quantities of gas than there is to track electrons in a power grid, there are more options for the design of a green gas GO scheme. However, ultimately similar caution would be advised for customers considering entering into a green gas tariff as a green electricity tariff – it remains advisable to check that tariff is linked to genuinely additional generation of green gas.

At the UCL level, emissions from construction account for an estimated 15% of the university’s total carbon footprint (HESA, 2021). Due to the carbon intensity of construction materials such as steel and cement, construction projects can have substantial lifetime carbon emissions.

Kelvin Saddul explored how alternative materials and techniques can contribute to reducing the embodied carbon associated with construction projects. Engineered timber frames are lighter and have lower embodied carbon than steel or concrete frames (Spear et al., 2019). They also have other advantages such as being amenable to prefabrication.

Cross laminated timber panels are constructed from glued layers of timber, which can be sustainably sourced from various woods such as scots pine, douglas fir, larch and mainly spruce (B1M, 2017). The production of CLT components only consumes 50% of the energy that is needed to produce similar concrete with 1% of that needed to produce steel (Hairstans, 2010). CLT panels can be used as a pre-insulated wall as well as roof cassettes (STA, 2015).

A ten-storey residential building in Dalston Lane, London, is constructed using cross-laminated timber (CLT) building from the first floor upwards. The material was chosen due to the constraints of an existing and planned railway line creating weight restrictions and making a piled foundation unfeasible. The material also resulted in substantially fewer deliveries to the site, reducing local disruption.

Nail-laminated timber is similarly constructed from layers of timber. An example is the T3 office building in Minneapolis, United States, a multi-storey building with 224,000 square feet of commercial space, which used NLT and glulam timber for structural components such as beams, columns floors, roof and furniture. The building was faster to construct than would have been the case with a steel or concrete frame, and was substantially lighter. The 3,600 cubic metres of wood was used within the structure are estimated to result in the sequestration of 3,200 tonnes of carbon during the lifetime of the building (Structurecraft, 2016). 

Laminated veneer lumber (LVL) is constructed of 3mm thick veneers which are glued together. It can be used to construct structural elements such as columns, beams and panels.  1m3 of LVL captures carbon equivalent to 789kg of CO2 (FWI, 2020). A timber-based 18-floor building in Brumnddal, Norway, uses LVL extensively. Timber window frames also have lower carbon impacts than aluminium equivalents.

Cement is a key material in concrete and a source of carbon emissions. Recycling concrete and using secondary aggregates offers a great opportunity in reducing waste, as well as a reduction in the associated environmental costs of exploiting natural resources. Ground Granulated Blast Furnance Slag (GGBS) is created from a by-product of the iron-making industry and can be used as a cement substitute. One tonne of concrete using GGBS emits 0.07 tonnes CO2, compared to 0.95 tonnes CO2 for one tonne of Portland cement (Hanson, 2021). The London 2012 Olympic Stadium made extensive use of recycled aggregate.

Green roofs and green walls can improve the air quality of surrounding areas by reducing the heat island effect and absorbing pollutants. Green roofs insulate buildings from higher temperatures, and reduce water runoff.

Good project management is also key to sustainability. Project deliverables are discovered within the front-end stage of the construction project and encompass the clients’ needs and wants and requires the project manager to outline the methods of achieving those goals.

India Goodwin and Tshiamo Ramano analysed the greenhouse gas emissions arising from the procurement of two product categories which are significant within the Bartlett’s overall procurement budget: laptops, and paper products.

Their analysis drew on life cycle analysis (LCA) data for relevant or comparable products, as identified in academic literature, or as provided by the suppliers themselves. They combined these LCA estimates with Bartlett faculty financial data showing quantities of products bought during the 2018, in order to derive estimates of total life-cycle greenhouse gas emissions associated with the product types.

LCA is a form of analysis which can be used to quantify the total inputs to – e.g. materials – or outputs from – e.g. environmental impacts – a product over its whole life cycle. LCA is a useful tool to determine the quantity and source of a product’s GHG emissions, also known as a ‘carbon footprint’.

The “life cycle” of a product typically covers extraction of the raw materials needed to make the product, the manufacturing of the product and its distribution, and may also extend to its usage and end of life disposal. Specifying exactly what is covered by the LCA – the “system boundary” – is crucial. In their analysis, Goodwin and Ramano draw on data referring to two commonly used system boundary definitions for the product types. “Cradle-to-gate” includes the extraction of raw materials, the transport of these materials, manufacturing of components from these materials, assembly of components to create a finished product, and product distribution. “Cradle-to-grave” includes all the aforementioned phases, with the addition of the use and end-of-life disposal phases.

Based on literature data, the mean value for cradle-to-gate emissions per laptop was found to be 163 kg CO2 eq, while the mean value on a cradle-to-grave basis was 230.2 kg CO2 eq. The range of values for cradle-to-grave estimates was significantly larger than for cradle-to-gate, indicating increased uncertainty around assumptions connected with the use and disposal phases.

Cradle-to-grave values for laptops were also gathered from data provided by suppliers. The mean was 225.2 kg CO2 eq, a similar value to the mean of the literature estimates, though from a smaller range.

The manufacturing phase tends to be the most significant, representing between 72% and 97% of total cradle-to-grave emissions, according to supplier data. 
The LCA estimates for laptops were combined with faculty financial procurement data, from which it was possible to derive estimates of the total emissions associated with the Bartlett’s purchase of laptops in 2018. Using literature LCA values, the mean total cradle-to-gate emissions are 16,955.5 kg CO2 eq., and the mean cradle-to-grave emissions are 23,938.3 kg CO2 eq. Based on LCA data provided by suppliers, the mean total cradle-to-grave emissions would be 23,423.5 kg CO2 eq.

Literature-based LCA values were also explored for various kinds of paper product. Use of recycled paper can reduce emissions relative to virgin paper, however this is dependent on the source of energy used to power the recycling process. Where renewable energy sources are used for the recycling process, this can deliver lower emissions; however, if the energy source is derived from fossil fuels, recycled paper can actually cause higher emissions than virgin paper (van Ewijk et al. 2021). This is shown in the LCA values assembled from the literature, which include some examples of carbon footprint for recycled paper that are higher, per functional unit, than equivalent values for virgin paper.   

When emissions factors for paper products are scaled up to the Bartlett level, it is noticeable that the highest overall emissions for the three categories considered are associated with recycled copy paper. This partly reflects the inclusion in the data of LCA estimates that assume the energy source for the recycling process is fossil fuel-based, as discussed above. However, this result is also due to recycled copy paper having considerably higher quantities purchased, in kilogrammes. 

The range of total emissions for virgin copy paper is 48.61 – 67.66 kg CO2 eq. with a mean of 48.61 kg CO2 eq. The corresponding values for recycled copy paper are 251.5 – 365.5 kg CO2 eq. and 299.3 kg CO2 eq. For tissue paper, the range is 101.00 – 296.00 kg CO2 eq., with a mean of 168 kg CO2 eq. This results in a total emissions range of 380.32 – 729.12 kg CO2 eq., with a mean of 515.48 kg CO2 eq. for the Bartlett. 

This initial scoping analysis already provides some useful high-level information about the contribution of different procurement categories to Bartlett emissions. The first observation is that total emissions from laptops -  mean value 23,423.5 kg CO2 eq, cradle-to-grave, supplier data -  is considerably higher than total emissions from the paper products analysed – mean value 515.48 kg CO2 eq. This is useful information in terms of the prioritisation of actions – in this case, laptops look to be a larger source of emissions than paper procurement.

Further research in this area will add more detail to this, providing indication of how other product categories compare in terms of emissions, and eventually how the whole area of product procurement compares against other sectors such as building emissions, travel, etc. As an initial indication of this kind of comparison, the Bartlett sustainability report from Sustainable UCL tells us that emissions from Bartlett air travel was 1,752 tonnes in 2018/19. This is a strikingly different story to the comparison between “ICT” and air travel at the UCL level, where emissions were comparable, and indeed ICT greater in 2019/20. Clearly the category of ICT is more than just laptops, and there is more work to do on data to understand the real Bartlett level situation. However, it stresses the importance of doing this kind of bottom-up work, as it can usefully complement and perhaps enhance other top-down approaches.

This study produces some preliminary recommendations to consider going forward.

The calculations in this study involved some level of approximations due to imprecise detail given in financial accounts (for example, the particular make and model of laptop is not always specified). Once we have a clearer view of our overall procurement emissions, it might be worth working with Finance colleagues to see if we can encourage people to provide a little more detail for certain items.

We can also consider building relationships with suppliers that are committed to reducing product emissions through measures such as product take-back and refurbishing. For example, by using recycled materials, notably recycled aluminum, to produce the 13-inch 2018 Macbook air, Apple were able to reduce the product’s lifecycle emissions by 47% on the model produced in the previous year (Apple, 2018).

The analysis of paper LCA emissions shows the importance of the source of energy used in the process, in terms of how significantly recycled paper reduces emissions relative to virgin paper. For products such as paper, we may need to examine our suppliers and the life-cycle emissions associated with their specific value chains, and make procurement decisions appropriately.

Will Chantry investigated the emissions associated with The Bartlett’s travel, focusing on three types of travel: academic travel, international student travel and commuter travel. 

A critical question raised by this study is that of scope. At present the travel of international students to and from their home countries to attend UCL is not included in the scope of emissions pertaining to UCL’s 2030 net-zero target. However, some have called for international student travel emissions to be included in university emissions targets, due to the likelihood that they are significant in relation to other sources of travel emissions (Mitchell-Larson et al., 2021). 

The category of academic travel was most straightforward to analyse, as the data is captured in a tool called Tableau. However, some discrepancies were observed in the data outputs of this tool, suggesting the need to check that the way the data is captured by this tool is consistent. The other two categories required some estimations and assumptions. For commuting travel emissions, the UCL-wide estimates provided by HESA (2021) were scaled down to the Bartlett-level based on relative numbers of students and staff. For international student travel emissions, the numbers of international students from different regions of the world were ascertained, and travel emissions from those regions estimated, assuming two return trips per student per academic year.

Based on these assumptions it was found that international student travel contributed most to the Bartlett’s travel emissions, emitting an estimated 11,463 tonnes CO2, primarily due to students travelling from Asia. This was followed by academic travel, which emitted 3,031 tonnes CO2, and finally commuter travel, which was estimated to have emitted 389.6 tonnes CO2 in 2018/19. Expressed in shares, the study estimated that international student travel represented over 75% of all travel emissions, while academic travel accounts for just under 25% and staff/student commuting is responsible for only 2.6% of all travel emissions. Chantry also estimated that Bartlett academic travel emissions accounts for 13.3% of the UCL total, while the faculty only has 6% of UCL staff and just over 8% of UCL students.

The study recommends that, due to the likely high contribution of international student travel emissions these should be included within the net-zero targets of the Bartlett and UCL. Accordingly, it recommends that the Bartlett should consider recording international student travel data as this would enable more accurate analysis and subsequent generation of emission-reduction recommendations. It also recommends reviewing the Tableau system in light of apparent data inconsistencies. 

It makes a number of suggestions which could contribute to reducing emissions in each of the three categories. For academic travel, recommendations for emissions reductions include regionalising and digitalising academic conferences and meetings. Many scholars highlight the transformative potential of videoconferencing for reducing the need to travel for conferences, meetings and presenting work (Arsenault et al., 2019).  Regionalisation involves finding the least emitting location for a conference considering the location of all conference participants. Hybrid versions are also possible, where for example a central hub houses conferencing equipment while smaller nodes tune in virtually and interact online.

Another suggestion is to introduce environmental risk assessments and a carbon calculator to the Bartlett travel bookings, to require staff to question whether the travel is necessary or whether the desired activity could be achieved any other way, or the travel achieved by a lower impact mode. Staff could be encouraged to adopt emissions reduction pledges, for example to reduce their travel emissions by 40% for 2030. However, universities often promote an internationalisation agenda that encourages academic travel and scholarly careers are often assessed on global mobility. UCL, and the sector as a whole, need to find a way to measure success in the academic field whilst incorporating environmental sustainability,

For international student travel, options to continue to engage globally while reducing student travel emissions could include establishing branch campuses in different countries. Collaborative delivery is a similar concept, whereby UCL could partner with a University on another continent to deliver a joint degree programme. Meanwhile high-quality carbon offsetting could reduce environmental impacts short-term. 

Regarding commuter travel, attempts to promote cycling, through provision of facilities such as bike storage and shower facilities, and services such as cycle route maps may help encourage mode shifting.  Teleworking may contribute to reducing travel emissions. However, increased energy use from heating and cooking at home, alongside continued mandatory electricity use at an empty campus, could partly offset emissions savings. As blended working is increasingly adopted, it will be important for campus buildings to be responsive and turn down according to use.

Arpana Giritharan examined the promises and pitfalls of carbon offsetting. In theory, offsets can enable organisations to claim carbon-reduction credits by funding projects that reduce emissions elsewhere. However, offsets have also been criticised as being ineffective in delivering genuine emissions reductions, and of causing other negative social and environmental impacts, and are perceived by some as “green washing”.

The purchasing of “emissions credits” used to claim offsetting creates carbon markets. These can be divided into two subgroups: compliance markets that arise due to the regulation of carbon emissions by international, regional, or national policies; and voluntary markets, which arise due to the voluntary purchase of emissions credits by organisations or individuals, without regulatory pressure. The voluntary offset market has been valued at around $300 million annually (Barron et al., 2021). However, voluntary offsets accounted for only 104 MtCO2e in 2019 (Donofrio et al., 2020), which is less than 1% of the anticipated 125 GtCO2e that needs to be removed over the 2020s to limit global warming to 1.5°C. 

Another important distinction between offsetting methods is between those that achieve greenhouse gas reductions, and those that bring about removals. Reduction offsets reduce emissions relative to a baseline, for example by substituting a carbon-intensive process with a renewable energy or other lower-carbon process. Removal offsets remove CO2 from the atmosphere, through nature-based solutions (NBS) including afforestation and reforestation, or through negative emission technologies (NETs) including direct air carbon capture and storage (DACCS) and bioenergy carbon capture and storage (BECCS).

There are a number of factors to consider to ensure emission credits claimed through offsets are genuine. Additionality refers to the principle that offsets must be linked to emissions reductions that would not otherwise have occurred. With the global ambition now to reach net-zero emissions by mid-century, offsets based on reductions relative to a higher-carbon baseline have diminishing credibility. Thus arguments are increasingly being made to shift away from reduction and towards removal-based methods (Allen et al., 2020; Mitchell-Larson et al., 2021).

It is also important to consider temporal factors. Some removal techniques may risk short-lived carbon storage with a higher risk of being reversed within decades.  For example, ongoing monitoring would be required to ensure that trees are not cut down a few years after reforestation resulting in sequestered carbon being released into the atmosphere (Barron et al., 2021). Equally, for tree-planting projects the full extent of the carbon credit may be based on the full lifetime growth of the tree, and hence it may take decades for the full offset to be delivered, during which time the carbon remains in the atmosphere.
The wider social and environmental impacts of offsetting projects can also be significant. Nature-based-solutions can create co-benefits for biodiversity due to habitat restoration through mechanisms such as afforestation, reforestation, and peatland restoration. Positive social impacts are also possible, as projects may create jobs for local communities. However, large-scale land-based projects can adversely affect biodiversity, and displace local communities from land, reducing livelihoods and threatening food security.

Due to all of these factors, an appropriate level of monitoring and verification is also crucial. Reforestation projects already take place in a sector that is prone to corruption in the form of state looting, elite capture, theft and fraud, and this can be exacerbated by poorly regulated offsets. A number of certification bodies exist for voluntary markets, including the Verified Carbon Standard (Verra) and Gold Standard Verified Emission Reductions, and Climate, Community and Biodiversity Standards. These standards have varying levels of rigor (Scholes and Smart, 2013) when evaluated against different indicators. Critics of offsetting have accused airlines such as British Airways and EasyJet of claiming to use offsets verified by Verra, but which lacked robust principles and generated what is known as ‘ghost credits’ or ‘phantom credits’ (Sandler Clarke and Barratt, 2021).

Many Higher Education Institutions have made net-zero pledges. Barron et al., (2021) also identify 11 HEIs that have already declared carbon-neutrality. In aggregate, 77% of emission reductions claimed by these institutions were achieved by carbon offsets, unbundled renewable energy certificates, and bioenergy (Barron et al., 2021). One of the institutions achieved its net-zero target with 100% offsets.

Carbon offsetting techniques currently deployed at UCL include: (1) Flight tax charged at 1.72% of the spend on flights, (2) a partnership with Trees for Life to offset travel emissions and (3) a partnership with PrintReleaf to offset paper consumption. According to Sustainable UCL, the levy on flights raises approximately £170,000 annually, out of which £80,000 is reinvested in campus energy efficiency and the allocation of the remainder is not yet known. Trees for Life grow native trees in the Scottish Highlands to restore the Caledonian Forest and includes a UCL grove for staff and students to offset their carbon emissions. Each tree is charged at £6 and fixes 0.25 tonnes of carbon over 100 years (University College London, 2021). Carbon emissions from print activity are not fully known, as PrintReleaf is in its early stages of being implemented. 

Bearing in mind the risks and controversies of offsetting, it has been proposed that offsetting should only be considered in the context of a hierarchy that prioritises demand reduction, efficiency and mitigation, leaving offsetting as a final resort. 

If offsetting does have to be resorted to, various sets of criteria have been proposed with which to evaluate offsetting options. According to Barron et al. (2021), high quality offsets should fulfil the PAVER criteria (Permanent, Additional, Verifiable, Enforceable, and Real). UCL has set the principles for offsetting providers which include Additionality, Social impact, Verifiability, Communicability and Cost. 

Similarly, in his investigation of travel emissions discussed above, Will Chantry identified Mitchell-Larson et al.’s (2021) seven-fold criteria: permanence; additionality; avoidance of double-counting; avoidance of “carbon leakage”; accurate carbon accounting; atmospheric outcome secured; and sustainable.

Sophia Worth drew from horizon scanning methodologies to scan available literature for signals as to possible future trends, challenges and opportunities for universities seeking emissions reductions. She identified nine areas for attention, covering technological, social and behavioural, and infrastructure and policy trends.

6.1  Demand for emissions reductions

Students have shown a higher than average and rapidly increasing concern about climate change – this will enable student engagement in change, while universities will also face more stringent demands on their climate action. Student concern for climate change is extremely high at over 90% (SOS UK, 2021). There is therefore likely to be high interest and motivation for changes to education, research and other activities to reflect the urgency of climate action, as well as increasing demands by students for emissions reductions by universities.

Government attention to climate change is increasing, for example with recent financial and policy commitments, which may result in new funding and infrastructure opportunities as well as demands set on universities. However, as it stands there have not been any specific decarbonisation targets set for the higher education sector.

Broader attention to climate change is increasing, which could lead to wider and growing expectations on universities. Net-zero targets are being set by organisations across public and private sectors, some going further with “climate positive” targets. However there are some criticisms of such plans, especially in relation to their reliance on carbon offsetting. There is increasing scrutiny on sustainability plans of universities, including from groups such as People and Planet and the Fossil Free Campaign, with attention being drawn to the scope of emissions included in universities’ climate targets.

6.2  The digital shift and remote working and learning

Remote working and learning could present opportunities to reduce emissions associated with travel. However, digital technologies may also contribute emissions. Energy use and emissions contributions of digital technologies are highly uncertain, but one estimate places the share between 1.4 and 5.9% of global emissions (The Royal Society, 2020, p.72) – with potential for further growth. A holistic approach to IT-related emissions needs to account for impacts as well as savings achieved by new technologies.

The rapid shift to online working during the pandemic highlighted opportunities for more flexible working, but challenges were also reported, including loss of creativity and ability to offer personal support, and loss of sense of community. However, considerable opportunities remain in the realm of digitisation. For example, Georgia Tech has established ‘hubs’ for in person learning in different physical locations, increasing connections with local communities.

6.3  Technologies for emissions reductions in universities

Electrification of energy systems is a crucial step for decarbonisation. Universities can be important spaces for leadership and research in practice. Universities could be sites for learning and experimentation in smart buildings (Kourgiozou et al., 2021), and for demonstrating the importance of consent and trust as a precondition for smart technologies (Véliz & Grunewald, 2018). Lifecycle assessment of emissions is also important to assess the full impact of technological choices.

6.4    Partnerships, accounting and systematisation

Cooperation on a range of emissions reduction challenges will help to standardise, give infrastructure, and keep accountability. For example, the EAUC Carbon Coalition is an alliance of universities and other high education institutions that are joining together for their emissions offsetting activities. UCL is working with an online platform called NETpositive that seeks to help its suppliers to account for and improve their contributions to/ impact on environmental and social issues. What happens on the institutional, sector, city, and national levels, is also important for university climate action, suggesting the importance of maintaining networks and communication.

6.5    Equalities and wellbeing

Climate justice aims to ensure that emissions reduction does not result in other harms for people and planet; this also applies in university settings. For example, digitalisation and remote working may present opportunities to reconsider how disability is accounted for in the university setting, but may also risk ignoring and excluding the needs of different groups. It is important to ask, “who benefits”, and to engage in stakeholder dialogue and participatory design of climate action policies and initiatives.

Climate change may exert a significant mental health burden in the future, including through ‘eco-anxiety’. Meanwhile action on climate change may confer a range of wellbeing-related benefits, including access to nature, and improvements in student employability as a result of engaging in climate action.

6.6 Difficult to eliminate emissions

Because of persistent hard to eliminate emissions sectors, significant reductions in overall use of energy will be needed, in addition to technological substitution of energy production, in order to reach net zero. This means that energy efficiency and behavioural interventions will be extremely important for energy use reductions across the board. Demand reduction must be a key part of the Bartlett’s climate action strategy. There is demand for carbon offsetting to be used as a ‘last resort’, to be better regulated, and to become significantly more expensive since these are currently too cheap.

6.7 Resilience

University infrastructures, including buildings, must consider resilience to future climate impacts, including increased challenges keeping buildings cool in the summer.

6.8 Travel policies

Explane lists a range of advice for reducing emissions from academic travel including the ErasmusByTrain initiative where universities provide cost subsidies for those who choose alternative travel for their Erasmus exchange, offer a toolkit for organising university emissions reductions, and have produced a Thoughtful Travel Pledge for academic institutions. EAUC have produced best practices for creating digital conferences (Scotland EAUC, 2020). It has been argued that online conference can help to “decolonise” academia, by encouraging localisation of work, and removing financial barriers of the cost of travel to international conferences.

6.9 Supporting and implementing innovations

It is important to engage students and staff to create changes now. “We do not have the luxury of time to wait for graduates to emerge who know something about future possibilities. We need to exploit the creativity, intelligence and ideas of our students before they have graduated.” (Allwood et al., 2019, p. 45). Examples of implementing this principle include Vertical Integrated Projects at Georgia Tech and the University of Strathclyde, where students work at long term research projects on complex questions throughout their degrees; and the UCL Living Lab, where UCL encourages use of the university as a case study for research, teaching and practice.

Achieving the Bartlett’s target of net-zero greenhouse gas emissions by 2030 requires coordinated action across a range of sectors. It will require developing effective partnerships between students, professional services staff, and academics, within the Bartlett and across UCL. It will also require coordination across multiple levels of governance, including the local and the city-level, and reflection upon our global impact and responsibilities as London’s global university.

Cutting emissions from buildings requires further analysis of energy building performance data in particular buildings, to identify options for behavioural measures, retrofit and building energy management, including timing of energy load and the role of thermal storage. We should also analyse the potential for onsite renewables at Bartlett buildings, and ensure that our green energy tariffs are genuinely additional. The decarbonisation of UCL’s heat network could be pursued by accessing waste heat from local sources – this would require partnerships with other bodies such as TfL.

Any new construction projects should consider the potential for alternative materials, including timber-based products, recycled concrete, and green roofs and walls, in reducing the carbon footprint of construction, alongside other co-benefits. 

Emissions associated with procurement can vary substantially across different product supply chains, but there are significant opportunities to reduce product embodied emissions through procurement choices, and through developing relationships with suppliers to enable reuse and refurbishment of products where appropriate.

There are important questions of where to draw the scope boundary for emissions to be included in the net-zero target, and this is particularly the case for travel emissions. Online and virtual environments could increasingly enable connection and communication without travel, and geographically distributed hubs for conferences, or branch campuses, could help reduce travel of staff and students.

Offsetting is likely to be required to meet a net-zero target. However, it should be approached within a hierarchy that prioritises demand reduction and mitigation. Care must be taken that offsetting investments are truly additional in greenhouse gases saved, and that they do not have wider social or environmental negative impacts.

Considering future trends, demands for genuine emissions reductions are likely to grow, especially from the student body. Universities can be crucial test grounds for new technologies and approaches, with students playing an active role. Net-zero strategies also need to consider resilience to future climate changes, and to consider EDI impacts to ensure an overall just transition.

Allen, M. et al. (2020), "The Oxford Principles for Net Zero Aligned Carbon Offsetting", Oxford Net Zero, (September), p. 15.  

Allwood, J.M, Dunant, C.F, Lupton, R.C., Cleaver, C.J., Serrenho, A.C.H., Azevedo, J.M.C., Horton, P.M., Clare, C., Low, H, Horrocks, I, Murray, J., Lin, J., Cullen, J.M., Ward, M., Salamati, M., Felin, T., Ibell, T., Zho, W., and Hawkins, W. (2019), “Absolute Zero”. UK FIRES, University of Cambridge.

Arsenault, J., J. Talbot, L. Boustani, R. Gonzalès and K. Manaugh (2019), "The environmental footprint of academic and student mobility in a large research-oriented university", Environmental Research Letters, 14, 9.

B1M. (2017, April 26), "What is Cross Laminated Timber (CLT)?" Retrieved from The B1M

Barron, A. R. et al. (2021), "Carbon neutrality should not be the end goal: Lessons for institutional climate action from U.S. higher education’, One Earth. Elsevier Inc., 4(9), pp. 1248–1258.

Carbon Trust (2019), Energy procurement and green tariffs. London: Carbon Trust.

Castellanos, J.A.F., Coll-Mayor, D. & Notholt, J.A. (2017), "Cryptocurrency as guarantees of origin: Simulating a green certificate market with the Ethereum Blockchain", 2017 5th IEEE International Conference on Smart Energy Grid Engineering, SEGE 2017, pp. 367.

Celsius, (2020), "Heat recovery from the London Underground in Islington", United Kingdom. [Accessed 10 July 2021].

Concept Energy (2022) Energy Procurement – a business guide. [Accessed 7th July 2022].

Donofrio, S. et al. (2020), Voluntary Carbon and the Post-Pandemic Recovery.

ECOHZ (2021), Make impact with ECOHZ GO2. [Accessed 31 July 2021].

Emeakaroha, A.; Ang, C.S.; Yan, Y., (2012), "Challenges in Improving Energy Efficiency in a University Campus Through the Application of Persuasive Technology and Smart Sensors", Challenges 2012, 3, 290-318. 

Erhart, D. et al., (2016)., "Retrofitting Existing University Campus Buildings to Improve Sustainability and Energy performance".

Fabi, V., Barthelmes, V., Heo, Y. and Corgnati, S. (2017), "Monitoring and stimulating energy behavioural change in university buildings towards post carbon cities".

FWI. (2020), LVL Handbook Europe. Finnish Woodworking Industries.

Gomaa, M., El- Darwish, I. (2017), "Retrofitting strategy for building envelopes to achieve energy efficiency".

Hairstans, R. (2010). "Off-site and Modern Methods of Timber Construction: a sustainable approach". TRADA Technology.

Hamburger, Á., 2019, "Is guarantee of origin really an effective energy policy tool in Europe? A critical approach", Society and Economy, 41(4), pp.487-507.

Hanson. (2021). "Regen GGBS - Cement Substitute".

Hast, A., Syri, S., Jokiniemi, J., Huuskonen, M. and Cross, S. (2015), "Review of green electricity products in the United Kingdom, Germany and Finland", Renewable and Sustainable Energy Reviews, 42, pp.1370-1384.

Henrique Lagoeiro, Revesz, A., Davies, G. & Maidment , G. (2019), "Heat from Underground Energy London" CIBSE Technical Symposium.

Herbes, C., Rilling, B. and Ringel, M. (2021), £Policy frameworks and voluntary markets for biomethane – How do different policies influence providers’ product strategies?", Energy Policy, 153, p.112292

HESA (2021), Estates management.

Ecotricity.co.uk [Accessed 31 July 2021].

Kourgiozou, V., Commin, A., Dowson, M., Rovas, D. and Mumovic, D. (2021), "Scalable pathways to net zero carbon in the UK higher education sector: A systematic review of smart energy systems in university campuses", Renewable and Sustainable Energy Reviews, 147, p.111234. 

Interreg North West Europe, (2021), "5GDHC in short" [Accessed 30 July 2021].

Islington Council, "Bunhill 2 – Project Partners" [Accessed 29 July 2021].

Klein et al. (2012), "Coordinating occupant behavior for building energy and comfort management using multi-agent systems".

Long, A. and Murphy, J. (2019), "Can green gas certificates allow for the accurate quantification of the energy supply and sustainability of biomethane from a range of sources for renewable heat and or transport?", Renewable and Sustainable Energy Reviews, 115, p.109347.

Mitchell-Larson, E., T. Green, E. Lewis-Brown, N. Jennings, C. Joly, F. Goodwin, D. Reay, R. Rothman, C. Scott, M. Allen and P. Forster (2021), "How can carbon offsetting help UK further and higher education institutions achieve net zero emissions?". 

Mulder, M. and Zomer, S. (2016), "Contribution of green labels in electricity retail markets to fostering renewable energy",  Energy Policy, 99, pp.100-109.

Ofgem (2021), "Renewable Energy Guarantees of Origin (REGO)". [Accessed 31 July 2021]. 

Ofgem (2018), "Default tariff cap: policy consultation, Appendix 13 – Renewable tariff exemption".

Sandler Clarke, J. and Barratt, L. (2021), "'Top airlines' promises to offset flights rely on 'phantom credits'", Unearthed. 

Schmid, Horschig, Pfeiffer, Szarka and Thrän (2019), "Biogas Upgrading: A Review of National Biomethane Strategies and Support Policies in Selected Countries", Energies, 12(19), p.3803.

Scholes, R. J. and Smart, K. (2013), "Carbon Storage in Terrestrial Ecosystems", Climate Vulnerability: Understanding and Addressing Threats to Essential Resources, 4, pp. 93–108. doi: 10.1016/B978-0-12-384703-4.00411-1. 

Scotland EAUC (2020), “Travel Better Pledge: a Pledge Template for the FHE Sector”, The Alliance for Sustainability Leadership in Education.

SOS UK (2021), “Student opinion | Climate Change”, Students Organising for Sustainability United Kingdom.

Spear, M., Norton, A., Hill, A., Callum, P., & Colin, O. (2019), "Wood based panels in modern methods of construction for housing: greenhouse gas abatement analysis". Bangor University.

StructureCraft. (2016), "T3 Minneapolis Office Building". StructureCraft.

Song, W. H. et al (2019), "Modelling development and analysis on the Balanced Energy Networks (BEN) in London". Applied Energy, Volume 233-234, pp. 114-125.

STA (2015), "Cross-laminated timber construction - an introduction". Structural Timber Engineering Bulletin.

Sustainable UCL (2021), "Delivering a zero carbon UCL by 2030"

The Construction Index (2019), "HS2 reveals Euston vent shaft designs". [Accessed 28 July 2021].

The Royal Society (2020), “Digital Technology and the Planet: Harnessing computing to achieve net zero”. The Royal Society.

Tovey, K., Turner C. (2006), "Carbon reduction strategies at University of East Anglia, UK"

University College London (2021), "Offset Your Travel".

van Ewijk, S., Stegemann, J. & Ekins, P. (2021) "Limited climate benefits of global recycling of pulp and paper", Nature Sustainability, volume 4,  pp. 180–187 

Véliz, C. and Grunewald, P. (2018), "Protecting data privacy is key to a smart energy future," Nature Energy, 3(9), p.702–704.

Wills, T. (2020), "Corporate procurement of renewable energy – implications and considerations".

Wilson, R. (2020). "Cullinan Studio-designed Bunhill 2 Energy Centre completed in Islington", Architects Journal.