ADD2863 Strengthening the climate resilience of London’s trees 2026-27

1.1.    Trees and woodland are a critical part of London’s climate-adaptation infrastructure. They help to: 
•    manage heat 
•    improve air quality 
•    support biodiversity 
•    manage surface water 
•    contribute to health and wellbeing outcomes across the capital.

1.2.    In November 2025, the Greater London Authority (GLA) published Future Climate Suitability of London's Public Realm Trees. The report concluded that, if nothing changes, over 72 per cent of London's current public realm tree population may struggle under future climatic conditions.  The report made a series of recommendations to strengthen London’s urban forest and reduce this risk. These included: 

•    improving guidance for delivery partners leading on future planting in London 

•    addressing the supply-chain barriers that restrict the availability of climate-resilient species for delivery partners managing London’s urban forest.

1.3.    The proposed work will directly contribute to: 
•    the London Environment Strategy target to increase London’s tree canopy cover by 10 per cent by 2050

•    the Heat Ready London objective to ensure trees can thrive in future higher temperatures (priority area of focus 4.2). 

It also contributes directly to implementation of the London Urban Forest Plan 2025 Actions Update. This identifies Resilience as a core “principle for success”, that underpins the future management of London's urban forest. In particular, the projects will support delivery of Actions 1C, 1D and 1F, for which the GLA acts as either co-lead or supporting partner. 

1.4.    These actions seek to: 
•    improve understanding of climate vulnerability across London’s public tree population 

•    develop evidence-based species recommendations for future climates 

•    strengthen preparedness for pests and diseases.

This will be done through coordinated monitoring, management and contingency planning. The work will better equip those managing trees in London to respond effectively to the challenges of future climate change and maintain London’s tree canopy. 

1.5.    This decision delivers against the Delivering a Greener, More Climate-Resilient London delivery plan (approved under MD3384). This aims to improve access to nature; and drive climate adaptation equitably across London. It also complements tree equity investments being delivered under MD3413 (improving climate adaptation and greening in London). 

1.6.    The proposed activity sits within project 1.3 of the Delivering a Greener, More Climate-Resilient London delivery plan: increasing London’s tree canopy cover through partnership action. This focuses on convening and collaboration with delivery partners and researching tree resilience in urban environments to increase and maintain London’s tree canopy. It forms part of the ‘accelerating delivery’ group of projects. 

1.7.    In this way, the proposed activity supports the Mayor’s commitment to continue world-leading action to tackle the climate crisis and build a greener London.

1.8.    This decision would enable the GLA to progress this area of work in 2026-27. 

1.9.    Some activities in this decision will be delivered by procuring specialist technical consultancy and research support. All such work will be procured in accordance with the GLA’s Contracts and Funding Code, and relevant procurement requirements.

Activity 1:  Improve species guidance for London’s local authorities and other delivery partners, by including threats from pests and diseases.

1.10.    Climate stress, and threats from pests and diseases, interact closely. Trees weakened by heat and drought are often more vulnerable to pests and diseases. At the same time tree-selection decisions – made with the aim of improving climate resilience - may introduce different patterns of biological risk.

1.11.    A specialist technical consultancy will be procured to assess current and future impacts that pests and diseases have on London’s public realm trees. It will integrate the findings with the GLA’s recent climate-suitability guidance.

1.12.    The outputs will support local authorities, and other institutional tree managers, planners and policy makers, in making more informed decisions about future planting and urban-forest resilience.

1.13.    Without this updated guidance, delivery partners across London will be poorly equipped to respond to the changing risk from pests and diseases in a changing climate. This may lead to the unnecessary loss of public-realm trees, and the cooling and other benefits they offer London. This would also put further pressure on London’s wider canopy cover, and the Mayor’s target to increase it.

Activity 2: Practical recommendations to strengthen London’s supply chain for resilient trees

1.14.    Stakeholders and delivery partners have identified a significant mismatch between the long-term planning required by tree nurseries (due to the time it takes to grow trees), and the short-term financial and procurement cycles facing many public sector buyers.

1.15.    A specialist technical consultancy will be appointed to examine how to create a stronger and more credible demand, so as to generate supplier confidence in the market; and encourage investment in the production of resilient tree stock. The work will: 

•    explore how demand for trees is communicated and coordinated 

•    examine procurement and commercial constraints 

•    assess mechanisms such as forward purchasing and contract growing 

•    identify feasible pilot approaches for future implementation.

1.16.    The work will focus particularly on London local authorities; but it will also consider other major public, charitable and private purchasers of public-realm trees. Outputs will include:

•    a review of procurement and purchasing practice among major purchasers of public realm trees in London

•    an assessment of barriers and opportunities within existing supply arrangements.

•    an appraisal of mechanisms such as contract growing, forward purchasing and aggregated demand

•    recommendations for future pilot activity.to inform delivery of tree-equity interventions; these interventions will be driven by MD3413 (improving climate adaptation and greening in London), and by future action from members of the London Urban Forest Partnership.

If this work is not delivered, delivery partners across London may be less able to source the tree stock needed to adapt London’s urban forest to the future climate. This would further accentuate existing pressures on London’s wider canopy cover, and the Mayor’s target to increase it.
 

2.1.    Objectives are as follows:

•    To enable progress towards the London Environment Strategy’s target, to increase tree canopy cover across London by 10 per cent, by 2050

•    To support delivery of Heat Ready London’s priority area of focus 4.2, to ensure trees can thrive in future higher temperatures

•    To give delivery partners the information, tools and practical approaches required to improve the long-term resilience of London’s urban forest

•    To improve understanding of current and emerging risks affecting London’s urban forest - including those arising from climate change, and pest and diseases 

•    To enable more informed tree selection, planting, protection and management decisions by integrating evidence on climate suitability and tree health

•    To implement recommendations arising from the Future Climate Suitability of London's Public Realm Trees study

•    To strengthen the resilience agenda of the London Urban Forest Plan: 2025 Actions Update; and the way it is implemented.

2.2.     Outputs will include the following:

•    Evidence-based, practical, published guidance and decision-support tools for local authorities, landowners and other delivery partners responsible for London’s urban forest. These tolls may be used when selecting, procuring, establishing and managing trees, for better resilience and growth in the future.

•    Appraisals of delivery options, and recommendations for future pilot activity, to strengthen climate-resilient tree planting and urban forest management

•    Published technical assessments and recommendations on sourcing and selecting species; vulnerability to current and future pests and diseases; and the future resilience of London’s urban forest.

2.3.    Expected outcomes are as follows:

•    A more resilient urban forest, with healthier and more diverse climate resilient trees that continue to provide benefits into the future. These benefits include such as cooling; biodiversity enhancement; air-quality improvement; and surface-water management.

•    Stronger capacity (among local authorities, landowners and other delivery partners) to respond to climate risks affecting London’s urban forest.

•    Improved evidence and guidance to support climate-resilient tree selection, planting and management across London.

•    Reduced vulnerability of public-realm trees to climate-related stresses, pests and diseases.

•    Improved supply of climate-resilient tree stock resulting from a better understanding of barriers and opportunities.

•    Practical recommendations and implementation approaches that support the protection, management and expansion of London’s tree canopy cover.

•    Stronger evidence to support future investment, policy development and partnership action aimed at increasing tree canopy cover and urban forest resilience across London.
 

3.1.    Under section 149 of the Equality Act 2010, the Mayor and the GLA must comply with the public sector equality duty (PSED) and must have due regard to the need to:

•    eliminate unlawful discrimination, harassment and victimisation and any other conduct that is prohibited by or under the Equality Act

•    advance equality of opportunity between people who share a relevant protected characteristic and those who do not

•    foster good relations between people who share a relevant protected characteristic and those who do not.

3.2.    The ‘protected characteristics’ are: age, disability, gender reassignment, pregnancy and maternity, marriage and civil partnership (but only in respect of the requirements to have due regard to the need to eliminate discrimination), race (ethnic or national origins, colour or nationality), religion or belief (including lack of belief), sex, and sexual orientation. 

3.3.    Consideration of the PSED is not a one-off task. The duty must be complied with before taking a decision, at the time of taking a decision, and after the decision has been taken, to ensure that equalities impacts are kept under ongoing review.

3.4.    Black, Asian and Minority Ethnic Londoners, and lower-income Londoners, are more likely to live in areas of deficiency of access to green and blue spaces, or in areas where the quality of these spaces is poor. The London Green Infrastructure Framework highlights significant variation in access to green infrastructure and environmental benefits across London, including differences in tree canopy cover and exposure to climate risks such as extreme heat.

3.5.    The Delivering a Greener, More Climate-Resilient London delivery plan and this decision specifically respond to, and aim to tackle, these disparities. By targeting investment in supporting partnership work to better protect, manage, and expand London’s urban forest (particularly where it is most needed), and enhancing resilience to climate change, the activities set out in this decision form are designed to deliver benefits in communities that are more vulnerable to climate risks, such as extreme heat.

3.6.    No adverse equality impacts from this decision have been identified at this stage.
 

4.1.    Key risks include:

•    Procurement: difficulty securing suppliers with the specialist expertise required to deliver high-quality outputs within available budgets and timescales

•    Stakeholder uptake: recommendations may not be adopted by local authorities or other delivery partners if outputs are insufficiently practical or do not align with existing decision-making processes

•    Evidence and uncertainty: limitations in available evidence regarding future climate suitability, pest and disease emergence, and species performance may constrain the confidence that can be placed in some findings.

4.2.    These risks will be managed through robust procurement and contract-management processes, including: 

•    clearly specified deliverables and milestones 

•    ongoing engagement with technical specialists and delivery partners to ensure outputs remain practical and user-focused 

•    established arrangements around programme governance and budget management.

4.3.    There are no conflicts of interest arising from those involved in the drafting and clearance of this decision form.
 

5.1.    The spend proposed in this decision is detailed in the table below:

5.2.    The proposed spending is financed by the Climate Emergency reserve. This is a planned use of reserves, as set out in the GLA Mayor budget for 2026-27. The spend has been included as part of the Delivering a Greener, More Climate Resilient London programme (MD3384), using budget line GE.0330.035.01 (increasing London’s tree canopy through partnership action).

6.1.    This work will be delivered according to the following timetable:

6.2.    The commissions will be managed by GLA officers; and will include engagement with members of the London Urban Forest Partnership and relevant stakeholder groups.

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