Baker Consultants

The Expert Witness’ view on the Ecological Assessment of air quality

In the Summer 2020 edition of the Expert Witness Journal, Baker Consultants’ Managing Director, Andrew Baker, discusses the ecological assessment of air quality and the need for multi-disciplinary expert witnesses.

Andrew has long experience in giving evidence as an expert witness in a number of different public inquiry cases.  He is often called upon by senior barristers to stand as an ecology witness and has worked on a number of air quality cases in recent years.

On the challenges of cooperation between the ecology stand point and other disciplines called to give evidence at inquiries, Andrew observes, “As a veteran of many ‘call in’ inquiries, examinations in public of Local Plans, planning appeals, hearings into Development Consent Orders and Parliamentary Select Committees, I am very familiar with the rigours of being on the stand as an expert witness. As an ecologist I am used to working in teams of planners, heritage consultants, hydrologists, noise consultants etc”

“While there is often some crossover between my area of expertise and the other disciplines, exploration of air quality issues requires an entirely new level of interdisciplinary cooperation. The work of the traffic consultant, air quality expert and the ecologist need to be seamless.”

Updated guidance on air quality assessments can be found via Natural England, IAQM and Highways England, that all focus on thresholds below which ecological effects can be ruled out. Each discipline assessing air quality therefore needs to be aware of the guidance, which in practice, causes problems.

A High Court decision in March 2017 (Wealden District Council v Secretary of State for Communities and Local Government, Lewes District Council and South Downs National Park Authority [2017] EWHC 351 (Admin) led the judge in the case to criticise the guidance that was in place at the time. With the ecological effects of air quality at the forefront of the environmental agenda, air quality policy makers, conservation bodies and lawyers have had these issues brought into sharp relief.

The print edition will be available from early August, and the electronic version is available online for free for subscribers on the website link below – flip to page 40 to read the full article:


Andrew’s other key areas of expertise are nature conservation law, Habitats Regulations Assessment and bioacoustics.  For more information or advice get in touch via contact form on the website, you can call us on +44 (0)1629 593958 or email us on