Mitigating climate change and tackling poor urban air quality are two of the most prominent environmental issues facing the planet. My previous blog post introduced how these two problems are interlinked and how integrating the approach to tackling these issues presents both major opportunities and challenges to policy makers. The Royal Society hosted a PolicyLab event to discuss this topic on Thursday March 24.

Professor David Fowler FRS chaired a panel including Professor Martin Williams of the Environmental Research Group at King’s College London; Sarah Legge, Chair of Environmental Protection UK’s Air Quality Committee ; Andy Eastlake, Managing Director, Low Carbon Vehicle Partnership; and Oliver Lord, Air Quality Manager, Greater London Authority. A diverse range of stakeholders, spanning academia, industry, NGOs and policy, were in attendance and joined in the discussion.

Clearing the air PolicyLab

Prevalence on the political agenda

The panel agreed that a divergence in policy approach between the two issues had been created over the last 20 years. This reflected a much higher priority given to climate change policies, with a lack of consideration of trade-offs affecting air quality. Sarah Legge emphasised the consequences of a non-integrated approach and highlighted incentivising diesel vehicles as a key example of this discord.

Martin Williams noted that, while the scientific community did raise health concerns in the 1980s and 90s, there was now a much stronger weight of quantitative data on health effects of poor air quality, as demonstrated by the WHO’s review of the health aspects of air pollution. The panel agreed that following the Paris Agreement on Climate Change and the rapidly growing interest in air quality, for example following the VW emissions scandal, the two issues now hold a very prominent and more equal place on the public and political agenda, offering a major opportunity to align the policy approach to these connected problems.


Embracing the synergies

The panel emphasised that developing an integrated approach would offer the most cost effective solutions to the two problems. Martin Williams outlined the co-benefits a joined up approach could have in terms of climate, health impacts and crop yield, highlighting a number of measures that would have substantial co-benefits. These include: energy/fuel efficiency and demand management; non-fossil fuel based energy such as wind, solar, tidal and nuclear; lower emission vehicles; and nitrogen efficiency in agriculture. There was also agreement with an audience comment, suggesting there are major co-benefits in tackling Short Lived Climate Pollutants (e.g. black carbon and methane).

Sarah Legge also emphasised the importance of an overall reduction in fuel usage as well as promoting and facilitating cleaner ways to travel, such as cycling and walking. Andy Eastlake stressed that, within the transport sector, there is a need to incentivise cleaner, low-carbon vehicles that are used in an optimal and efficient way. Oliver Lord discussed the potential for decentralised energy, emphasising the potential for local renewable generation as well as more efficient transmission at the local scale.


Confronting the trade-offs

Significant trade-off issues were also discussed, and Martin Williams argued that these will need to be confronted to establish a unified approach to the problems. In particular, he highlighted the issues of uncontrolled diesel, biofuels/biomass, and combined heat and power generation, which can have positive climate impact but negative air quality impact. For example, Sarah Legge noted that biomass can have a much lower climate impact than coal, oil and gas, but can cause localised emission hotspots creating poor air quality in specific areas.

Andy Eastlake picked up on the ‘uncontrolled’ aspect of diesel emissions as an issue to target. He argued that it is essential to ensure appropriate treatment measures exist for exhaust emissions in vehicles as well as robust on-road testing and evaluation procedures, as these measures have not yet made the desired impact on emissions. He emphasised that the process for evaluation needs to be uniform for all types of vehicle and for different pollutants e.g. carbon dioxide (CO2), particulate matter (PM), nitrogen oxides (NOx), in order to provide a common assessment standard.


Challenges for achieving an integrated approach

The panel discussed the major challenges facing policy makers in achieving an integrated approach, mainly with reference to the transport sector, although they also stressed importance of other key sectors, such as energy generation, the built environment and agriculture.

Andy Eastlake emphasised it is important to enable mobility for the population in the most effective possible way. Oliver Lord highlighted the challenge that local authorities face in managing the increasing demand on the road network in cities, faced with the continual pressure of a growing population. He noted there is expected to be a 60% increase in congestion in the centre of London by 2031. He noted that a key element within this is the movement and delivery of goods on the roads, with 90% of goods within London currently being moved on the road network.

It was warned that technological innovations will not be the only factor in solving these problems. For example, while vehicles can be designed to be ‘low emission’ in terms of exhaust, there is an increasing problem due to non-exhaust emissions of PM, such as from brake and tyre wear. Therefore, while there are major gains to be made for NOx due to lower emission vehicles, the picture for PM is much less clear.

Additionally, there are major uncertainties in the emission estimates from vehicles, for example for pollutants like NOx, which impacts on the accuracy of computer models estimating the potential impact of different interventions.


The key stakeholder: the consumer

Members of the audience questioned the panel on whether diesel vehicles should be banned, as leaded petrol had been previously, in response to similar health concerns. The panel recognised this concern but argued that banning diesel vehicles could be detrimental to consumers, as a significant proportion of passenger and goods vehicles are diesel. However, they did agree that, while a ban on diesel may not be appropriate, there is a need to remove and replace the most highly emitting vehicles, such as buses and taxis, from the vehicle fleet.

Andy Eastlake also argued that, in terms of the transport sector, the key to improving both the climate and air quality impact lies with the consumer. He argued that there is currently a lack of information available to the public on the environmental impacts of vehicles and that there is a need for improved labelling and guidance for the consumer to encourage the uptake of cleaner low emission vehicles as well as their efficient usage.


Envisaging a future policy approach

This PolicyLab discussion revealed how the integration of climate change and air quality policies has local, national and international dynamics. For example, Oliver Lord highlighted the issue of trans-boundary emissions and the impact of poor air quality originating from overseas. The panel agreed that it is important to unify the two issues institutionally. They warned of the danger that can result from fragmented approach if different government departments or different levels of government (local, national, EU), have different approaches and priorities.

Looking ahead, the panel were asked by the audience, at what level the policy decisions for aligning these two important issues needs to come from? The panel argued that it is important for this integration to be considered at a high level and at the beginning of the policy making process. Martin Williams highlighted the creation of the Clean Growth interdepartmental committee as a potential example of such a high-level approach. It was envisaged that a national-level, multi-tiered framework would help enable an integrated approach to tackling air quality and climate change.