Cleaner Air for Scotland 2: environmental report

An Environmental Report to assess the likely significant environmental impacts of the new air quality strategy.

3. Environmental Objectives

3.1. Introduction

3.1.1 The 2005 Act requires that the Environmental Report includes a description of the relevant aspects of the current state of the environment and its likely evolution without implementation of the draft CAFS2. It also requires a description of existing environmental problems along with relevant established environmental protection objectives.

3.1.2 The following table provides a high level summary of the key environmental pressures for each of the SEA topic areas. A more detailed environmental baseline is provided in Appendix A.

Table 3. Key environmental pressures by topic


  • Key pressures on air quality include emissions from transport, industrial, domestic, agricultural, natural and transboundary sources outwith Scotland.
  • In urban areas, transport emissions are the biggest source of air pollution.
  • Emissions of the majority of air pollutants have declined in recent years, with ammonia declining at a slower rate than other pollutants.
  • Ammonia is recognised as a key air pollutant that can have significant effects on both human health and a detrimental impact on soils, water and biodiversity.
  • Poor air quality continues to affect human health and the environment in some areas.

Population and human health

  • Key pressures on population and human health include outdoor air pollution which is known to cause damage to human health across a wide range of conditions.
  • Highly urbanised areas are likely to have higher concentrations of pollution than rural locations.
  • Early deaths and other health impacts can be associated with indoor air pollution with sources differing by setting but including emissions from burning fuels for heating and cooking.
  • Air pollution and the consequent impacts on human health are not evenly spread and are disproportionately linked to more vulnerable groups and deprived areas.
  • Climate change has the potential to exacerbate poor air quality and associated health problems.

Climatic factors

  • Air quality and climate change are intrinsically linked as they both arise from broadly the same sources.
  • Key pressures include greenhouse gas emissions from a range of sectors including transport (37%), agriculture and related land uses (24%), business/Industry (22%), energy (15%), and residential (15%).
  • Climate change has the potential to exacerbate key pressures on a range of environmental receptors
  • Climate change could alter current patterns and concentrations of air pollution.
  • Key inter-related climate change risks include:
    • flooding and coastal change risks to communities, businesses and infrastructure
    • high temperature-related risks to health, well-being and productivity
    • shortages in the public water supply, agriculture, energy generation and industry
    • risk to natural capital, including terrestrial coastal, marine and freshwater ecosystems, soils and biodiversity
    • risk to domestic and international food production and trade
    • new and emerging pests and diseases and invasive non-native species, affecting people, plants and animals


  • Air and soil quality are linked through common sources of pollution.
  • Changes in land use and management can result in change in soil organic matter which impacts on soils ability to perform its range of functions.
  • Soil pollution and contamination can be locally significant and threats to soil can be exacerbated by misuse of chemicals; waste management and recycling operations during development.
  • Ammonia deposition linked to modern agricultural practice can lead to the acidification of soil negatively impacting biodiversity.
  • Key pressures on soil can also be compounded by the effects of climate change which can contribute to both erosion and compaction.


  • Key pressures on water in some areas include changes to water flows and levels resulting from land use change, invasive species, poor water quality and overall ecological condition.
  • Atmospheric deposition associated with activities such as fertiliser use can have an effect on both air and water quality.
  • Key pressures on freshwater include physical changes to beds and banks and rural diffuse pollution.
  • Similarly to soil, ammonia deposition can lead to the acidification of water, negatively impacting biodiversity, flora and fauna.
  • Groundwater quality can be affected by diffuse rural pollution, whereas groundwater flow and levels can be affected by agricultural irrigation and industry.
  • Diffuse pollution as a result of atmospheric deposition can effect both water and air quality and increased nitrogen concentrations can lead to acidification and eutrophication of water bodies.

Biodiversity, flora and fauna

  • Air pollution can cause damage to plants and animals and other impacts on biodiversity that can result in species loss, habitat composition changes and increased sensitivity of organisms to environmental stresses.
  • Ammonia is a key pollutant and nitrogen deposition is a key pressure on a wide range of habitats and nitrogen emissions from combustion plants, intensive agriculture and transport causes acidification, eutrophication and direct tissue damage to plants.
  • Key pressures on biodiversity include the spread of invasive species and wildlife disease, land use intensification and modification, pollution and climate change.
  • Climate change including shifting weather patterns can affect nature across the country.

Material assets

  • Key pressures include emissions associated with agricultural practices, mostly dominated by ammonia release when slurries, manures and nitrogen fertilisers come into contact with air, leading to diffuse pollution in water and soil.
  • Intensive land use/ land management practices are leading to pressures on associated natural resources such as land (and environmental receptors such as soil, water and biodiversity).

3.2. Likely evolution of the environment without implementation of CAFS2

3.2.1 The SEA process requires an assessment of the likely evolution of the environment without the implementation of the plan.

3.2.2 The draft CAFS2 has a key role to place in ensuring that sufficient actions are in place to address air quality improvement. CAFS2 brings together existing policies and proposals on air pollution, climate change, carbon reduction, and mobility and recognises that these are strongly interconnected. It also introduces measures to tackle air pollution relating to domestic combustion and agricultural emissions, nitrogen deposition and environmental impacts.

3.2.3 The proposed joined up approach to improved air quality across a range of sectors (such as climate change and mobility) can support multiple benefits and environmental outcomes that could be missed in the absence of CAFS2. For example, air quality and climate change are intrinsically linked and in the absence of CAFS2, an opportunity could be missed to develop a concerted effort to tackle the main sources of greenhouse gas emissions which are also sources of air pollutants (e.g. transport).

3.2.4 While concentrations of most key pollutants in Scotland are compliant with EU standards and some are already below World Health Organisation (WHO) guideline values, there are some general, local and periodic poor air quality areas which require urgent attention and action. In the absence of CAFS2, poor air quality trends could continue and have an adverse impact on a range of other environmental receptors as well as population and human health.

3.2.5 Further in the absence of new measures to tackle air pollution resulting from domestic combustion and agricultural emissions (Theme 7), poor air quality trends could continue and have an adverse impact on a range of other environmental receptors including population and human health.

3.3. The current regulatory framework

3.3.1 There are a range of existing regulatory controls in place which serve to improve air quality locally. These include Air Quality Management Areas (AQMA) and Smoke Control Areas[4]. In addition, Part 2 of the Transport (Scotland) Act 2019[5] confers new powers on local authorities in relation to the creation, and civil enforcement, of Low Emission Zones (LEZs). This supports the Scottish Government’s commitment to introduce LEZs into Glasgow, Edinburgh, Dundee and Aberdeen. LEZs set an environmental limit on certain road spaces, allowing access to only the cleanest vehicles with the aim of improving air quality in Scotland’s city centres. Vehicles that do not meet the emission standards set for a LEZ will not be able to drive within the zone and a penalty charge will be payable by the vehicle’s registered keeper, unless the vehicle is either out of scope of the LEZ or is exempt.

3.4. Relationship with other Plans, Programmes and Strategies

3.4.1 The following paragraphs provide a summary of the key statutory measures, including plans, programmes and strategies (PPS) framing air quality management in Scotland, expanding on the draft CAFS2’s high level policy context as illustrated in Figure 1.

3.4.2 Key PPS originate from international treaties which are implemented as legislation at the EU, UK and Scotland levels[6]. Key EU air quality legislation includes Directive 2008/50/EC on ambient air quality and cleaner air for Europe ('the Directive')[7], Directive 2004/107/EC relating to arsenic, cadmium, mercury, nickel and polycyclic aromatic hydrocarbons in ambient air ('the 4th air quality Daughter Directive')[8] and Directive (EU) 2016/2284 on the reduction of national emissions of certain atmospheric pollutants (National Emissions Ceilings Directive or NECD)[9].

3.4.3 The NECD sets national emission ceilings for certain atmospheric pollutants (nitrogen oxides, non-methane volatile organic compounds, sulphur dioxide, ammonia and (new in the 2016 Directive) fine particulate matter PM2.5). It implements at EU level obligations under the United Nations Economic Commission for Europe (UNECE) Convention on Long-Range Transboundary Air Pollution of 1979 (CLRTAP) and, in particular, its 1999 Protocol to Abate Acidification, Eutrophication and Ground-level Ozone of 1999, which was revised in 2012 (the revised Gothenburg Protocol). The NECD transposes 2020 targets agreed under the revised Gothenburg Protocol, along with more ambitious targets for 2030.

3.4.4 The NECD has been transposed into domestic law through the National Emission Ceilings Regulations 2018 and the requirements will be implemented at UK level through a National Air Pollution Control Programme[10]. Although the UK is on course to meet the 2020 targets for all pollutants (other than ammonia), new policies will be required to ensure 2030 compliance.

3.4.5 The Directive sets health and environment-based objectives and values for limits of certain air pollutants. These include particulate matter (PM), sulphur dioxide, nitrogen dioxide and oxides of nitrogen, lead, benzene, carbon monoxide, and ozone. Meanwhile, the NECD sets national emissions ceilings (mass emissions) for oxides of nitrogen, sulphur dioxide, non-methane volatile organic compounds, ammonia and PM. These must be met by prescribed dates. Air quality is devolved and these legal requirements are the responsibility of Scottish Ministers.

3.4.6 At the UK and Scotland Level, the Environment Act 1995 (EA95)[11], the Pollution Prevention and Control Regulations 2012 (PPC)[12], and the Clean Air Act 1993 (CAA93)[13] are particularly relevant regulatory drivers for protecting air quality.

3.4.7 The EA95 establishes the Local Air Quality Management (LAQM) system which requires local authorities to regularly review and assess air quality in their areas against objectives for several pollutants of concern for human health. Where an authority identifies a risk of an objective being exceeded at a relevant location, an Air Quality Management Area (AQMA) must be declared after which the authority must prepare an air quality action plan setting out how it proposes to tackle the issues identified. SEPA provides regulatory oversight and has reserve powers under Section 85 of EA95 (with the approval of Scottish Ministers) to direct local authorities to fulfil their duties and also provides significant support and advice to local authorities on LAQM and wider air quality matters.[14]

3.4.8 Under PPC, Scottish Environment Protection Authority (SEPA) regulates prescribed industrial activities which require a permit to operate. Permits contain measures to control emissions to air (such as abatement systems) and suitable emission limit values (ELVs) for both point and fugitive sources for certain substances, and requires monitoring to be conducted which allows compliance to be assessed. In setting appropriate permit conditions, SEPA must have regard to the requirements of the Air Quality Strategy for England, Scotland, Wales and Northern Ireland (the AQS)[15].

3.4.9 Emissions to air of smoke which are not captured by PPC may be controlled through the provisions of the CAA93. This is not a permitting regime, but action is taken by local authorities in response to public complaints. The Act seeks to control emissions of dark smoke, smoke, grit, dust and fumes from smaller-scale/non-PPC activities, and the provisions can cover both domestic and commercial premises. The Act does not apply to activities which have a PPC permit. Local authorities can monitor for air pollution from these activities and take action via investigations, notices and prosecutions. SEPA also has powers in relation to the declaration of Smoke Control Areas (SCAs) but has no regulatory powers under the Act[16].

3.4.10 The upcoming Heat Decarbonisation Policy Statement and updated Energy Efficient Scotland Route Map will set out our policy proposals and actions to drive down emissions from heating our homes and buildings. This is central to meeting the ambitious climate change targets set out in the Climate Change (Emissions Reduction Targets) (Scotland) Act 2019. In addition to delivering reductions in CO2 emissions, these actions will also contribute to reduced air pollution by reducing the need for supplementary domestic heating.

3.4.11 The Committee on Climate Change (CCC), which is the Scottish Government’s statutory advisor on climate change, produced a report in 2018, Biomass in a Low Carbon Economy[17], which explored how biomass could be prioritised for the most valuable end use. The CCC recommended a transition on the use of biomass away from domestic heating and towards use in timber construction and Bioenergy Carbon Capture and Storage (BECCS).

3.4.12 Due to the wide ranging impacts of nitrogen at the local to global scale, a partnership project has been initiated between Defra, the devolved administrations, the country nature conservation bodies and JNCC. The Scottish Government is a part of the project’s steering group. The project, called Nitrogen Futures[18], is being undertaken by a consortium led by the Centre for Ecology & Hydrology (CEH) which brings together leading expertise with the aims to compare current and possible future emission reduction policies to help maximise the benefits to ecosystems and the people that live near them. Following the completion of the project, a report will be produced detailing the methods and results of modelling the different policy scenarios together with the optimisation of the spatial targeting of NH3 and NOx mitigation measures. The report will also discuss how emission mitigation scenarios might interact with other policy areas such as those dealing with climate change. The Nitrogen Futures project will also produce case studies to demonstrate how scenarios work in practice at local scale. Country-specific and UK-level resource packages to assist with communicating the results to a wider audience will be developed.

3.4.13 Finally, studies are emerging exploring the effect of the COVID-19 pandemic currently being experienced. Time variance analysis of air quality in Scotland during COVID-19 lockdown shows that NO2 and particulate matter emissions experienced significant drops (between 9% and 81% compared to previous years depending on pollutant)[19]. In addition, recent reports outline what Scotland can learn from the lockdown experience to create safer, attractive urban spaces which put people first to make walking and cycling the norms for everyday journeys[20]. These recognise opportunities to improve our urban environments in the context of changing congestion patterns and associated challenges for air pollution and climate change.



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