The Good, the Bad and the Ugly - Assessing Greenhouse Gas Emissions and Evaluating their Significance

15 March 2022

Climate change is still considered a relatively new topic within EIA and the guiding principles are ever emerging and inconsistent. As the Institute for Environmental Management and Assessment (IEMA) release their second guidance document on how to assess Green House Gas (GHG) emissions for development proposals, BWB reviews the key changes, and considers if they improve the assessment process.

The Good - Significance, Mitigation and Cumulative Effect 

Hopefully, IEMA has rescinded its statement that 'all GHG emissions will contribute to climate change, and thus might be considered significant, irrespective of whether this is an increase or decrease in emissions'. Instead it would perhaps be more beneficial to opt for a softer position in regard to the guidance, such as 'all emissions contribute to climate change, however specifically in the Environmental Impact Assessment (EIA) context, it now provides relative significance descriptions to assist assessment.' 

Whilst we as practitioners agree with the sentiment of the former, it was impractical as far as assessing effects and aligning with best practice - we welcome the change which goes some way in helping us:

1. screen projects successfully: formerly, the guidance that all projects must be considered EIA if they trigger the Schedule 2 thresholds, and
2. determine a more reasonable threshold for what is considered 'significant' in the project's context. Section VI describes five distinct levels of significance which are not solely based on whether a project emits GHG emissions alone, but how the project makes a relative contribution towards achieving a science-based 1.5°C aligned transition towards net zero. 

The latest guidance has also introduced a hierarchy to mitigation, which should result in improved development design from a GHG emission perspective at an earlier stage in a development. This hierarchy promotes the elimination of emissions in the first instance, bringing with it a greater emphasis on site selection, whilst asking more of developers during the design process. Only once options to limit effects on carbon sequestration and emissions embedded in the design have been exhausted can compensation (offsetting) be considered. No longer will offsetting be considered an easy way out of addressing effects within the developers control, encouraging mitigation to be considered earlier in the design process. 

How to satisfy the requirement to assess the cumulative effects of a development when 'all global cumulative GHG sources are relevant to the effect on climate change and therefore should be taken into account' has created a challenge to balance proportionality with feasibility - where do you draw the line? 

As IEMA explains, 'GHG emission impacts and resulting effects are global rather than affecting one localised area. The approach to cumulative effects assessment for GHGs differs from that for many EIA topics where only projects within a geographically bounded study area of, for example, 10km would be included'. 

The solution is that the effects of GHG emissions from specific cumulative projects should not be individually assessed, as there is no basis for selecting any particular - or more than one - cumulative project that has GHG emissions for assessment over any other. Where the contextualisation is geographically, or sector bound - e.g. involves contextualising emissions within a local authority scale carbon budget, or a sector level net carbon roadmap - then the consideration of cumulative contributions to that context will be within that boundary. Hopefully this will mean practitioners will no longer have to reason why they have not considered in combination effects of schemes in isolation - especially where they have not offered a GHG assessment themselves. 

However, there remains a significant trip hazard: 'it is down to the practitioner's professional judgment on how to best to contextualise a project's GHG impact'. Not particularly helpful if you should reach the blame game of an inquiry. 

The Bad - Screening

Whilst the new guidance addresses one of the issues associated with screening, it is let down by the shallow instruction determining whether a proposed project falls within the remit of the EIA regulations, is determined by whether it is likely to have a significant effect on the environment and therefore require an assessment. 

Though the new guidance slightly expands on how best to approach the subject during the screening process, the guidance states that 'in almost all cases, GHG emissions are likely to be a relevant factor at the screening stage', it does not provide a standardised approach to determine when an assessment of GHG emissions is required as part of an EIA. Given this, and the fact that there is generally a limited amount of information known on potential GHG emission sources at the screening stage, the lack of clear guidance may lead to local authorities requesting GHG assessments for every development, regardless of size or its potential to emit GHGs. This may however be good news for practitioners, as it may result in GHG assessments being requested for developments where the impact would not be significant. Nonetheless, this may increase costs for developers, as well as increase the amount of reading time of Environmental Statements for local authorities. 

However, new guidance also states that 'proposed mitigation measures that the developer has committed to which aims to avoid or prevent significant adverse effects may be taken into account when determining whether significant effects are likely to occur'. Again, this may encourage the elimination or reduction of potential GHG emissions earlier in a development's design.  

The Ugly - Proportionality 

Ensuring an EIA is proportionate to the potentially significant environmental impacts of a development is a central tenet of IEMA's EIA-related guidance. This proportionality leads to shorter, more focused Environmental Statements, which reduces the burden on decision-makers, as well as reducing the financial burden on developers. There has been a concerted effort to improve the proportionality of GHG assessments, but does it go far enough? 

Ideally, a GHG assessment should consider both direct and indirect sources of emissions during both construction and operational phases. Practitioners can set out an approach and methodology for the assessment of sources of emissions via a scoping report, which is sent to local authorities for feedback. However, the fact that no standardised approach is preferred to determine which sources of GHG emissions should be assessed at different stages of the planning process is a key limitation of IEMA's new guidance. In our experience, recognition that qualitative assessments are acceptable, for example where data is unavailable, or where mitigation measures are agreed early in the design phase with design and engineering teams, is not considered satisfactory. 

In setting out what to consider when determining a proportionate approach, in our experience, the omission of considering the planning process stage a vital component that more often than not, results in disproportionality; although assessing both direct and indirect GHG emissions may be possible for a development seeking detailed planning permission, it is often only possible to undertake a meaningful assessment on direct sources for developments seeking outline planning permission, as the level of detail for them is usually relatively low. 

For example, it is not possible to accurately assess the embodied carbon of materials to be used in construction when these materials are not yet known. Benchmarking may be used to estimate emissions from such sources; however, this is likely to overestimate the amount of emissions, and could result in a planning application being rejected based on the perceived significance of potential impacts. However, without a standardised approach for determining the scope of GHG assessments, it is our experience that some local authorities reject the proposed scope of works, often asking for a conservative assessment disproportionate to the application which may result in a meaningless assessment. This can lead to development delays and money lost for developers. 

We therefore ask what is to be done to assist the ruling authorities in understanding the key principles? It would be helpful for guidance to state which emissions sources should be assessed as a minimum at each stage of the planning application - this would inform developers of the level of detail required for a development to allow a proportionate assessment at the relevant planning application stage, as well as inform practitioners and local authorities as to which sources of emission need to be assessed as a minimum. 

At BWB we recognise the constraints to you gaining timely consent for your proposals; that's why our pragmatic and early engagement in masterplan design is a key factor in the successful delivery of sustainable developments. We have a wealth of growing experience in this area and continue to deliver successful schemes that will leave a lasting sustainable legacy. 

We have a number of exciting opportunities in the BWB Environmental Planning team across all our offices. BWB's growth aspirations ensure you'd be joining us at an exciting time, allowing you to progress your career in a forward thinking, award winning company that focuses on our people. 

To explore our current vacancies, visit our career page.