Five key takeaways from the ICAS Sustainability Summit 2026

Sustainability is about more than reporting requirements and carbon targets. At the ICAS Sustainability Summit 2026, one message was clear: organisations must move beyond measurement and embed sustainability in business decisions, risk management and planning for long-term resilience.

Bringing together professionals from sustainability, finance, investment and accountancy, the summit explored why sustainability remains commercially important, how businesses can make meaningful progress, and how accountants play a key role in integrating sustainability throughout a business including building trust in sustainability information. 

Across the keynote and two panels, speakers emphasised the cost of inaction, the need for a holistic approach and the importance of integrating sustainability into strategy. Trust in data, business decisions based on a comprehensive data set and the professionals who support and provide robust reporting against credible commitments was a core theme. 

Here are five key takeaways from the summit. 

1. The cost of inaction must be part of every business decision 

Keynote speaker Fiona Watson, Vice-President of Corporate Performance and Accountability at the World Business Council for Sustainable Development (WBCSD), urged organisations to consider not only the cost of action, but also the cost of doing nothing. 

Extreme weather, disrupted supply chains, changing resource availability and rising costs already affect insurance, transport, asset valuations, working capital and demand. Yet these consequences might not be immediately visible in financial statements. 

Finance professionals and management teams, therefore need to understand how environmental and social change affects the assumptions behind investment proposals, forecasts and procurement decisions. If those assumptions no longer reflect real conditions, organisations could undermine their resilience. 

Treating inaction as an active choice means comparing the cost of acting now with the realistic cost of waiting. Delay can bring greater disruption, more expensive solutions and fewer future options. Sustainability must therefore inform decisions before risks materialise, rather than remain a compliance exercise. Properly assessing the future, not just using a compliance checklist, and reflecting that analysis in forecasts and decisions is key, and one way where an accountant’s skills are vital.  

2. Meaningful progress requires more than counting carbon 

The first panel, featuring Tara Schmidt, Transition Finance Scotland; Russell Picot, Universities Superannuation Scheme; and Sophie Dejonckheere, Lloyds Corporate and Institutional Bank, explored why sustainability remains critical to commercial success and why businesses must move from looking backwards and prioritising measuring progress to looking ahead and delivering real-world change. 

One concern was “paper decarbonisation”: Reducing reported emissions or changing portfolios without cutting emissions in the real economy. Tara warned against focusing on targets without changing what businesses do. Decarbonising transport, heat and industry requires investment in the activities that enable transition; targets alone aren’t a strategy. 

As Tara put it: “Targets don’t equal a strategy. We need to focus not just on what we’re going to do less of in terms of CO2 emissions or water or so on, but what we’re going to do more of.” 

Sophie described “carbon tunnel syndrome”: Treating carbon reduction as synonymous with sustainability. Carbon matters, but a low-carbon development isn’t sustainable if it damages nature, harms communities or creates other serious risks. Decisions should consider climate, nature, social impacts and resilience together, including trade-offs and wider benefits. 

Sophie explained: “If we do not consider a fully integrated transition that looks at social considerations, nature integration, physical climate risk, then this won’t work.” 

Complexity can’t become an excuse for inaction 

Sustainability decisions are often complex and involve trade-offs, particularly when environmental and social priorities compete with commercial pressures. But complexity should prompt engagement, accountability and learning, not delay. 

Transition planning can turn ambitions into practical steps through supply chain work, business collaboration and engagement with government and communities. Changing consumption patterns and developing a circular economy can also reduce waste, strengthen supply chains and create opportunities. The test is whether business decisions deliver meaningful real-world change. 

3. The physical world doesn’t respect reporting boundaries 

Fiona also stressed the need to look beyond an organisation’s operations to its wider value chain. Reporting boundaries can hide vulnerabilities: A business might control its own sites yet remain exposed to supplier disruption, water shortages or changing conditions elsewhere. 

Finance professionals should connect environmental and social risks to operational and financial consequences. Low water levels on a transport route, for example, could raise freight costs, delay deliveries, reduce margins and increase working capital. Understanding that chain can inform sourcing, inventory and investment in resilience. 

Make assumptions explicit and keep challenging them 

Professional judgement is essential when information is incomplete. Organisations can’t always wait for perfect data: They should use the best available evidence, state assumptions clearly, document their reasoning and define what new information would trigger a review. 

This creates a continuous process of challenge, explanation and revision. Regularly testing assumptions against changing circumstances helps boards make informed decisions and strengthens trust in how they reached their conclusions. 

4. Accountants have a critical role in building trust and integrating sustainability into business 

The second panel featuring Laura Guittard CA, GSK; Martin Murray OBE CA, Swire Pacific Ltd; and George Cobb CA, We Are Salt Consultancy examined how professional accountants can improve information, strengthen governance and connect sustainability with strategy. Stakeholders need confidence that reported numbers are meaningful, assumptions are understood and claims can withstand scrutiny. 

Finance professionals bring expertise in governance, controls, assurance, measurement and professional judgement. Beyond disclosure, reliable sustainability information supports planning, investment and performance management. Linking objectives to targets and remuneration can also turn commitments into accountability. 

Bring sustainability into the wider business 

Panellists advocated closer working between finance, risk, sustainability and other functions, an approach that Martin has adopted in Swire Pacific. Rather than treating sustainability separately, organisations should integrate it into established processes, for example through one corporate risk register covering sustainability and other material risks. George described this level of integration as “the nirvana”, adding: “That is exactly where you want to be, that one register, that one process.” 

This integration clarifies trade-offs. Businesses moving from just-in-time towards “just-in-case” supply chains might hold more inventory or diversify suppliers, strengthening resilience while affecting costs, working capital and investment. Sustainability shouldn’t sit alongside business strategy; it should shape it. 

5. Building credible sustainability information is a journey 

Organisations are at different stages of maturity, and sustainability reporting often lacks the established processes, robust data and consistency of financial reporting. Building credibility takes investment and continuous improvement. 

The panel highlighted practical priorities: Appropriate frameworks, clear procedures, training and progressively better data. Organisations should be transparent about their starting point and ambitions while addressing weaknesses rather than accepting poor information indefinitely. 

As processes mature, organisations can strengthen their analysis and increase confidence in the information, including nature events and other potential crises and regulatory issues, they used to make decisions. As Martin commented “we must all focus on materiality things” 

Trust underpins progress 

Trust ran throughout the summit, from evidence and professional judgement to credible data, accountability and collaboration. It depends not only on numbers but also on transparent processes and people who are willing to challenge assumptions and change course when evidence develops. 

The closing discussion emphasised community: Professionals must share experiences and work across organisational boundaries on challenges that no organisation can solve alone. As Laura said: “I do believe finance definitely has a voice and should be using it... even if certain politics are trying to tell us the opposite.” Accountants can use their skills not only to improve reporting but also to influence decisions that shape long-term performance. 

Looking ahead 

The summit reinforced that sustainability is fundamentally about long-term value-creation, business success, resilience and responsible decision-making. Organisations were challenged to look beyond specifics like carbon metrics and disclosure, consider wider dependencies, risks and opportunities and deliver meaningful change in the real economy. 

CAs are well placed to connect sustainability with strategy through their expertise in evidence, controls, financial analysis and professional judgement. Credible reporting matters because of the decisions it supports. As Russell said, “while the board agenda might be full, inaction is costly, and we need to move from philosophy to a hard financial edge to approaches to sustainability”. 

By challenging assumptions, integrating sustainability into risk management and recognising the cost of inaction, CAs can help turn commitments into progress.