Impact case study database

Accurate measurement of the carbon stored in global forests is crucial in understanding and responding to the climate crisis since forests are key to reducing greenhouse gas emissions. Disney developed a new and more accurate method for measuring carbon in trees which enabled space agencies to validate their satellite estimates of carbon stocks. Disney’s approach has been recommended by the United Nations Intergovernmental Panel on Climate Change as their preferred method for estimating carbon stocks in forests. Charities have used Disney’s evidence of the value of urban forests in their campaigns, and Disney’s evidence has reached a large public audience of [Text redacted for publication] and an exhibition at the V&A.

Improving new spaceborne measurements of forest carbon

Disney has pioneered terrestrial laser scanning (TLS) methods for measuring forest structure and biomass [R2/R3/R4]. These methods are being used by NASA and European Space Agency (ESA) space missions to improve satellite estimates of carbon stocks. Prior to this approach, remote sensing estimates relied on simple relationships between tree size and mass, known as allometric equations, to extrapolate from small numbers of harvested trees to entire regions. These equations are necessary for all space-based estimates, but have large uncertainties. Disney was funded by NASA [iii] to collect validation measurements in high biomass forests in the US and Gabon across climate and environmental gradients for use in the Global Ecosystem Dynamics Investigation (GEDI) mission, launched in 2018. GEDI measures the height and structure of forests, helping quantify their role in global climate and global biodiversity. A lead scientist from the NASA GEDI Science Team, writes, “Research outputs by Prof. Disney and collaborators have been central to […] delivering the plot scale measurements and models needed for explicit linking of in situ measurements of forest structure with high resolution observations from spaceborne instruments such as GEDI and NISAR [NASA-ISRO Synthetic Aperture Radar]” [A]. This has improved the methodology used by the space agencies by allowing them to validate their satellite measurements: “TLS methods pioneered by Disney and colleagues provide a means to benchmark and improve the in situ measurements and models used by all space agency missions” [A]. Disney leads an ESA-funded consortium [i] providing critical calibration information for the 2022 BIOMASS mission, in French Guiana, Gabon and Borneo. The mission will provide height and density data specifically on tropical forests, how they are changing, and their role in the carbon cycle. NASA GEDI Science Team’s lead scientist confirms: “[Disney’s] TLS measurements and models from these campaigns have been used by NASA GEDI to validate vertical foliage profile estimates […] Without this work, GEDI would have to rely on [less accurate] generic allometric models for some of the tallest and highest biomass forests on Earth” [A]. Disney’s measurements provide improved tree height-to-mass relationships, enabling more accurate maps of forest C stocks to be produced.

NASA’s Committee on Earth Observation Satellites (CEOS) is an international consortium of approximately 60 agencies established to ensure coordination of civilian earth observation programs, and promote best practice. Disney co-chairs the CEOS sub-panel on calibration and validation of satellite biomass and the 2020 CEOS protocol cites Disney’s work on TLS measurement of tree biomass as the recommended ‘gold standard’ approach for national reporting of biomass validation [B], ensuring this can be done much more accurately and consistently than at present. The protocol was ratified in March 2021 and then publicly released. NASA GEDI Science Team’s lead scientist explains: “TLS is now established as a disruptive technology that is requiring us to rethink vegetation surveys for quantifying ecosystem structure and function” and its application “has far reaching implications for reducing the uncertainty of satellite-derived estimates of aboveground biomass maps being generated by the NASA GEDI and NISAR missions over the next 5 years” [A]. Accurate biomass maps are critical to enhance understanding of and responses to climate change, as well as elucidating the functioning and biodiversity of forests more generally.

Changing international guidance on climate change

Disney’s work has changed international policy guidelines for national greenhouse gas inventory (NGHGI) reporting, provided by the United Nations Intergovernmental Panel on Climate Change (IPCC). The most recent 2019 IPCC Good Practice Guidelines (GPG) for NGHGIs emphasises that adoption of transparent and reliable forest biomass estimation is key to effective forest carbon accounting and hence a vital part of implementing COP21 Paris Agreement policy. Disney’s work is cited by the IPCC GPG as a transformative approach: “Terrestrial laser scanning provides non-destructive and highly detailed measurements independent of the size and shape of a tree that are otherwise only available from destructive Disney et al., 2018 **[R2]**” [C1]. The IPCC GHG reporting guidelines must be adopted by all 195 signatories for the COP21 agreement. A lead author of the 2019 IPCC GPGs, confirms that Disney’s “ground-breaking work to develop a new, non-destructive approach” to carbon estimation “is being used to underpin satellite and ground-based estimates of carbon stocks in an integrated manner and leads to more precise and open data on tropical forest biomass” [C2]. Disney’s work has led to this direct change in IPCC GPG policy recommendations: “The revised inventory guidances have recognised and cited the work of M. Disney as a suitable approach for more consistent and accurate GHG reporting – so the approach is ready to be used by countries for their national estimation and reporting” [C2].

Demonstrating the value of forests to a public audience and providing data for use in campaigns by charities and practitioners

While the importance of urban forests for climate resilience, health and wellbeing is clear, Disney’s work shows that urban forests are likely to be undervalued by policymakers and practitioners involved in urban planning and development, particularly in terms of their carbon uptake potential [R6]. Disney’s new way to capture and express the benefits of urban forest is particularly important for communicating these benefits to practitioners and the public as we develop more climate-resilient and sustainable cities. Practitioners have recognised the value of Disney’s research in raising awareness of the value of urban forests. In 2018 the (then) Chair of the Forestry Commission, said: “This [R6] is exciting work. The trees in our cities are important. They matter because they are close to people and a key component of our urban environment providing beauty, shade and homes for myriad species as well as absorbing carbon and pollutants. [Disney’s] work is adding colour and detail to this understanding” [D]. This research complements the work of agencies such as Forest Research whose role is, in part, to estimate the value of urban trees. The Head of the Forest Research’s Urban Forest Research Group observed that “we should expect our urban trees to also be providing us with an important carbon sink, helping to combat the global trend of increasing carbon dioxide in the atmosphere. This new work by UCL [R6] is a welcome development in advancing this understanding” [D]. A Camden Councillor and Cabinet Member for Improving Camden’s Environment explained that Disney’s research: “unlock[s] the benefits of trees not just for our own residents but for people's benefit round the world" [D]. Disney has developed tools to help UK charity Trees for Cities (TfC), who fund and deliver tree planting projects in under-served urban areas in the UK and internationally, track the success of their planting projects. Due to the challenges of visiting planting sites, TfC had been unable to systematically review the health of 20 woodlands they had planted in London since 1999 until working with Disney in 2019. TfC’s Impact Coordinator said: “This work has enabled us to gain an indication of the status of our larger planted woodlands in London after 20 years of growth, without the need to visit them all individually. Disney’s work […] has provided us with […] quantitative data that allows us to speak with greater confidence about the impact we are having, to both internal and external stakeholders” [E]. While most sites were healthy, some were less so and identifying those using TLS: “allow[ed] us to target follow-up maintenance activities to maximise our impact”. In addition, Disney’s team’s use of open source software and data, plus the provision of a detailed workflow, has built TfC capacity so that “TfC are able to replicate the processes developed during the project as more data becomes available” [E]. TfC are now better able to monitor these sites.

Disney’s research has reached a large public audience, raising awareness of the value of trees through television programmes, press coverage, and a major design exhibition. He has also provided data for charities and policymakers to use within a UK-wide campaign to demonstrate the value of trees. In 2019, Disney was invited to participate in Friends of the Earth’s campaign ‘More Trees Please’. Responding to the government’s public consultation on its England Tree Strategy, ‘More Trees Please’ seeks to restore England’s forests and elicit a government commitment to double the amount of trees in England to tackle the climate emergency [F]. Disney’s film with Dan Snow in which he explains the role of trees in absorbing fossil fuel equivalents, and their environmental and wellbeing benefits, has been viewed over 55,000 times and Friends of the Earth’s petition to double England’s tree cover has been signed by 173,113 people (their target is 175,000). In the 2018 BBC documentary ‘Dame Judi Dench: My Passion for Trees’, Disney measured Dench’s favourite tree using TLS and discussed the significance of the tree with her in the context of global climate. The programme has been seen by an estimated [Text redacted for publication]. One viewer commented: “A revelation beautifully filmed, giving such a valuable insight into their hidden lives” and another “I thought I knew everything about trees! How wrong I was!” [G]. Press coverage of [R3] and [R5] in outlets from The Metro to The Financial Times has reached an audience of 105,000,000 [G]. Disney’s research also featured as a video installation (a 3D visualisation of a Brazilian rainforest, which played on a loop on a display screen) in a major 2018 exhibition at the Victoria and Albert Museum (V&A) in London, ‘The Future Starts Here’. The exhibition ran from 12 May 2018 to 4 November 2018, received over 110,000 paying visitors, and due to its popularity, was commissioned to tour other locations including Sweden (ArkDes, 21 March 2019 - 4 August 2019). The curator explained that Disney’s work changed their approach to the exhibition in places, shifting their focus “from ‘solutions’ in the technocratic sense – tools or technologies for reducing emissions […] to show how a deeper understanding of the natural environment can have vast consequences. We wanted to show our visitors that by changing the way forests are measured, can change their value, and may ultimately contribute to their preservation. In short, how a laser scan of a tree could help save the world” [H].

Disney’s development of new ways to measure trees and forests has achieved demonstrable impact in key ways via improving space-based observations, influencing policy recommendation on greenhouse gas reporting and influencing perceptions of trees and forests among forest professionals and the wider public.