8. Climate Change
A Scotland that reduces greenhouse gas emissions and achieves its renewable energy targets whilst delivering co-benefits for air quality.
Air quality and climate change – a joined-up approach
8.1 Climate change is one of the most serious threats facing global society  . Changes in several aspects of climate, such as an increase in temperature and changes in precipitation patterns can already be detected in Scotland  . The future impacts are expected to have far-reaching effects on Scotland’s economy, people and environment.
8.2 The interactions between air pollution and climate change are complex. For instance, if the predicted Scottish climate of hotter, drier summers is realised, an increase in cases of ground level ozone (O 3) pollution could be possible, with consequences for the health of people and ecosystems  .
8.3 On the other hand, emissions of pollutants that harm human health and ecosystems could have an important impact on the climate. For instance, some pollutants are also greenhouse gases (such as O 3) or contribute to greenhouse gas formation (for example, carbon monoxide). Particulate matter, depending on the size and composition of the particles, can reflect or absorb sunlight and can also influence cloud formation and snow melt.
8.4 Air quality and climate change are inextricably linked; air pollution often originates from the same activities that contribute to climate change. However, some policies to address air quality or climate change have not interacted (and, at times, have been in conflict) despite the potential benefits of joining up the two policy topics. The CAFS Governance Group will seek to change this. Although considering and tackling these areas separately may allow us to make some progress towards the respective environmental targets, it will also lead to unintended consequences and trade-offs. For instance, in the UK we have been incentivised to use diesel vehicles as they have less impact than petrol vehicles on the climate, but they typically have more impact on human health. Domestic biomass burning is another example of benefits for greenhouse gas emissions but a potentially negative impact on local air quality  .
Climate change today – what are we already doing?
8.5 Mitigating the effects of, and adapting to, climate change are perhaps the most significant environmental challenges for society today. In 2009 the Scottish Parliament passed the most ambitious climate change legislation anywhere in the world. The Climate Change (Scotland) Act 2009  requires Scotland to achieve at least an 80% reduction in greenhouse gas emissions by 2050 and sets statutory annual emission reduction targets. ‘Low Carbon Scotland: Meeting Our Emissions Reduction Targets 2013-2027 – The Second Report on Proposals and Policies’ sets out how Scotland intends to achieve these targets whilst delivering benefits for air quality and the wider environment. Reducing emissions in Scotland: 2015 progress report summarises the progress made towards the targets  .
8.6 Commitments to decarbonise the Scottish economy should help reduce air pollution, but choices about the route taken to 2050 will influence the scale of additional improvements for air quality. Energy efficiency and demand management, as well as a shift towards low or zero emission energy sources and transport for example, should provide mutual benefits for air quality and climate change. A summary of some policy measures and their respective impacts on air quality and climate change is captured in Figure 13.
Figure 13. Air quality ( AQ) and climate change ( CC) interations
Source – Air Pollution: Action in Changing Climate 
Black carbon – a case for integrating air quality, climate change and health
8.7 Black carbon, often referred to as soot, is the major component of fine particulate matter and results from incomplete or inefficient combustion of fossil fuels and biomass. Within the urban environment, black carbon is associated with the inefficient combustion of diesel in particular. The number of diesel-powered cars and vans on our roads has increased significantly over recent years, with the proportion of new diesel cars sold rising from 14% to 46% over the last decade. Black carbon is a serious threat to human health as the particles are very small and can enter the deepest parts of the lungs; the smallest of these can pass through the lungs and into the blood. In the atmosphere this pollutant contributes to climate change by absorbing heat; in polar regions it reduces the reflectivity of the snow, which also increases the absorption of heat and leads to melting of snow and ice. Although black carbon is considered to be short-lived and localised in the atmosphere in comparison to carbon dioxide ( CO 2), evidence suggests that its warming effect is 460 to 1,500 times stronger than that of CO 2  .
Energy and air quality
8.8 The use of fossil fuels to produce energy – mainly through gas and coal fired power stations, but also other methods such as waste incineration and the recovery of waste heat – contributes to air pollution. The impacts on air quality and the climate could be minimised by:
- making energy use as efficient as possible;
- moving to renewable energy sources; and
- using low emission fuels such as certain biofuels, liquid petroleum gas, biopropane and hydrogen, as shown in case study 4 (along with experimental fuels such as liquid air or liquid nitrogen).
Climate Change Tomorrow – What more do we need to do?
8.9 Climate change adaption and mitigation can bring additional benefits for air quality, which, in turn, may lead to human and ecosystem health improvements. In particular, we know that reducing carbon emissions by using more sustainable travel can result in cleaner air.
8.10 Climate change actions noted in ‘Low Carbon Scotland: Meeting Our Emissions Reduction Targets 2013-2027 – The Second Report on Proposals and Policies’ that help to protect and enhance air quality include:
- a largely decarbonised electricity generation sector by 2030;
- a largely decarbonised heat sector by 2050 with significant progress by 2030;
- almost complete decarbonisation of road transport by 2050, with significant progress by 2030; and
- significant modal shift from the private car to public transport and active travel.
- Ensure that future updates to the ‘Low Carbon Scotland: Meeting Our Emissions Reduction Targets’ publication on meeting our climate change targets take into account air quality impacts
8.11 A Sustainable Energy Action Plan is a key document in which signatories to the Covenant of Mayors  – a Europe-wide organisation representing local authorities of all sizes – outline how they intend to reach their reduction targets for CO 2 by 2020.
- Expect any Scottish local authority which has or is currently developing a Sustainable Energy Action Plan to ensure that air quality considerations are covered
8.12 The Low Carbon Scotland: Behaviours Framework  outlines what the Scottish Government will do to drive and support the move to low carbon living in the lead-up to the first key climate change target in 2020. Reducing emissions from transport is one of the framework’s main focus areas, which will also benefit air quality.
8.13 As part of its climate change commitments, the Scottish Government has set ambitious renewable energy targets for 2020:
- 100% electricity demand equivalent from renewables;
- 11% of demand from heat to come from renewables;
- at least 30% of the overall demand for energy to come from renewables; and
- 500 MW to come from community and locally-owned renewable energy
8.14 The Routemap for Renewable Energy in Scotland  , which is updated annually  , sets out how the Scottish Government intends to achieve these targets. Moving away from a dependence on fossil fuels will benefit both air quality and reduce greenhouse gases, provided that increased biomass uptake is managed well  .
- Work with Forestry Commission Scotland to publish updated guidance on the impact of biomass on air quality to help local authorities fulfil their statutory responsibilities (noting existing guidance as stated in footnote 93)