GreenLight Alliance: Our Time on Earth

20th June 2022

Benz Roos, Senior Lighting Designer at Speirs Major explains how the lighting of the Our Time on Earth exhibition at the Barbican echoes its message of creative responses to climate change.

We felt extremely fortunate to be asked to design the lighting for the exhibition Our Time on Earth, conceived and curated by Barbican International Enterprises (London) and co-produced by Musée de la civilisation (Québec City). The exhibition is themed around positive, creative responses to climate change and pressures on the earth’s fragile ecosystem. 

To quote guest co-curators Caroline Till and Kate Franklin: “The conversation about the climate crisis until this point has focused on depicting the scale of the problem – an approach that, while valuable, often evokes a sense of shame, helplessness and even paralysis. But we know that many brilliant artists, designers, and technologists are creating ways to help combat the climate emergency. We wanted Our Time on Earth to carve out space to imagine a constructive way forward.” 

In the spirit of the exhibition’s message, the design team’s brief was to design as sustainable an exhibition as possible to house the art pieces. The architects, Universal Design Studio, created a palate of natural and/or recycled materials such as Honext, corrugated hemp fibre sheets and hemp fabric for the exhibition design; and we challenged ourselves to design the most sustainable lighting scheme that we could.

The exhibition hosts 18 distinct artworks, each requiring its own unique atmosphere, with most of the artworks containing projections or screen-based content. The digital nature of the works contrasts noticeably with the natural material palette of the exhibition design. We aimed to softly highlight the innovative sustainable materials of the exhibition framework without distracting from the art installations.

Many video installations also include sculptures made from organic materials such as wood and recycled fabrics. Dramatic and focused light illuminates the sculptures in balance with the luminance levels of the screens and projections. For example, Liam Young’s Planet City film is accompanied by mannequins displaying the costumes by Hollywood designer Ane Crabtree. Traditional high-level spotlights illuminate the costumes, and in addition, linear diffuse glowing luminaires behind the sculptures interpret the film’s cinematography. This backlighting methodology also renders the beautiful textures of the fabric.   

Inspired by the artworks and the exhibition’s theme, we prioritised the consequences of our design decisions in parallel with designing for people’s experience of the exhibition. Early design discussions with the Barbican and the architects included ideas ranging from shades made from plant seeds to cable ties made from recycled rubber. The concept eventually settled on a few simple principles.  

1. Utilise as much existing equipment as possible. 

2. Design with minimal equipment in mind.  

3. Specify products suitable for the circular economy. 

4. Make sure the visitor experience is excellent.  

Circular economics and minimal (embodied) carbon were crucial principles from the start of our design process. The life span of exhibitions is usually shorter than lighting for buildings, and Our Time on Earth has a proposed life span of five years. The exhibition will travel once the show ends at the Barbican in August, so its temporary nature puts the question of ‘what happens to the products after their use’ into sharp focus. The relatively new CIBSE guidelines TM66 and TM65 helped us direct the specification towards circularity, and low embodied carbon.

We inherited a selection of older fixtures – Soraa Arc 100 track-mounted spotlights – from the previous BIE exhibition at the Barbican. The embodied carbon and circularity credentials are unknown for these luminaires; however, dedicated exhibition luminaires are very flexible by nature, so the lowest embodied carbon starting point was to re-use what was already available on site. The Soraa fixtures feature a snap-on system that is an easy and highly effective way of changing the beams to create the right ambience for each artwork. It made us realise that some traditional track light fixtures already contain circular principles in terms of in-built flexibility and ongoing use for different types of shows.

The exhibition required new luminaires in addition to the existing track lights. Having assessed the market, we found that the Stoane Lighting ZTA spotlight range was the natural choice for the equipment, particularly as Stoane Lighting is spearheading the circular economy in the UK. Its KTP (Knowledge Transfer Partnership) with Edinburgh Napier University and the Government’s Innovate UK allowed a complete project assessment of the circularity and carbon footprint of the design to be made. PhD chemist Dr Irene Mazzei assessed the overall design data, and her fascinating evaluation showed us the full carbon consequences of our specification and design decisions for the first time. Her study concludes that the total embodied carbon for the new luminaires in the exhibition is 2,262kg CO2e. To put this in context, 38 seedlings would need to grow into trees for at least 10 years to offset this emission to become carbon neutral. The TM65 study breaks down the material composition of the fixtures, telling us that raw materials, largely aluminium, make up at least 50% of the overall embodied carbon. At this point, the ZTA is a useful product because it is circular by design. The luminaires can be easily adapted and refurbished into new products with different light technical specifications or even mounting methodologies. The Barbican could utilise the product for new shows or light other spaces at the end of the exhibition.

The study also showed that electronics such as drivers significantly contribute to the overall embodied carbon of the lighting installation. Drivers are responsible for approximately 472kg CO2e (20%) of the 2,262kg CO2e. For future projects, we should keep this in mind; if, as is the case with this exhibition, we can design systems that share drivers, it might be possible to make further reductions in embodied carbon.

Dr Mazzei’s tables and diagrams have been an eye-opener in approaching lighting design. Until now our studio has always put the experience and the visual effect of the light as the primary focus at the concept stage, with the choice of the equipment that will deliver this not considered until later in the creative process. This relatively small project has allowed us to begin to adjust our approach, as designing with circular and low embodied carbon principles requires a slightly different attitude. To quote activist Clover Hogan: “Solving climate change is not your responsibility because it’s outside your control. What you are responsible for is the thing inside your control, indeed the only thing that has ever been inside your control: your mindset.”

Thinking towards the future, we can see that addressing climate change requires a new mindset for lighting design. We ought to dream much more extensively beyond beautiful lighting experiences. Some design ideas, like the shades made from seeds, which can be planted and grow after their use, make a captivating story. However, on working through the concept and discussing the embodied carbon, it becomes apparent that these ideas are little more than ‘green’ gimmicks. One of the artists, Biofabricate, presents a near future in which the fashion industry utilises bio-fabricated materials made by living cells. Using bio-fabricated materials is not a gimmick because it is not only about designing a fashion piece but also takes the entire system of production into account. As lighting designers, we have a responsibility to think more holistically about our approach. 

Regenerative design expert Sarah Ichioka has a good analogy for thinking about systems and consequences. For example, she urges shampoo manufacturers to create melanges that are good for our hair and rivers – where shampoo might end up. Similarly, lighting designers ought to consider the consequences of their specifications. Specifiers should ask questions like; what happens with the equipment after its use? How is the luminaire manufactured? Which materials are involved? It is immensely encouraging that CIBSE TM65 and TM66 provide some in-depth direction.

However, we should aspire to challenge ourselves further and interpret engineering guidelines creatively. Nairobi-based design studio Build X and Mycotile exhibit the material mycelium. Mycelium is part of the fungi kingdom and is the network of threads, called hyphae, from which mushrooms grow. Ikea is planning to replace all its use of polystyrene with this bio-material, and various decorative luminaires utilise mycelium already. It is easy to imagine components of technical fixtures could also utilise this material. The Soraa Arc is predominantly made from plastic, with a cast aluminium heatsink. But what if mycelium replaced the plastic components to reduce embodied carbon? After their use, when luminaires are dissembled for recycling or re-use, some elements would be able to biodegrade and become part of the ecosystem again. These components could become food for the 38 tree seedlings, allowing them to flourish and offset the embodied carbon for the lighting equipment of this exhibition.  

One of the key aims of the curators is to send a positive message to visitors. They want to present a positive future with solutions to climate emergencies. As designers, we have a lot to catch up on. Still, this exhibition has helped us take steps towards a lighting design process with holistic sustainability considerations built in from the beginning. 

Our Time on Earth is currently open until the end of August at the Barbican in London. We would like to thank the Barbican for the opportunity and Dr Irene Mazzei and Stoane Lighting for their support and insightful study.

This series is curated by Roger Sexton of Stoane Lighting,

Image: Tim P. Whitby