Postgraduate impact stories: Melissa Yeo. From plantation executive to institutional change agent.

15 October 2026 - Melissa Yeoh tells us how the knowledge, frameworks and networks she gained during her Postgraduate Certificate helped her drive initiatives in peatland restoration, human rights due diligence, ESG integration and institutional change throughout her career.

Programme: Postgraduate Certificate in Sustainable Business (PCSB), Value Chains stream, 2016-2017)  

Job title: Head of Sustainability and Communication, Samling Group of Companies. 

Why did you apply for postgraduate studies with CISL? 

I first encountered sustainability concepts in 2015 while working as a plantation executive in Malaysia, particularly through WWF Malaysia’s Theory of Change framework. My understanding was initially shaped by conservation and certification approaches used by organisations such as WWF and the RSPO to protect forests and biodiversity.  

Although my day-to-day role focused on operations, I saw wider sustainability issues discussed at organisational and policy levels, and I felt constrained by my position's limited scope to contribute meaningfully. This prompted me to explore sustainability’s broader influence on supply chain decisions, corporate value creation, and marketing strategy, aiming to build the knowledge and credibility to communicate effectively in both the field and the boardroom. 

Describe your experience of studying with CISL 

Studying with CISL was truly life-changing, in both expected and unexpected ways. Most humbling of all was the experience of being in Cambridge itself. I often questioned how I could make a meaningful impact on the global sustainability agenda. Being surrounded by others with the same determination and ambition for transformation, was deeply inspiring. Furthermore, the University of Cambridge's legacy and intellectual capacity had a profound impact on me, even as a temporary resident. 

Cambridge challenged me to raise my own expectations. You arrive intending to learn, but you leave with a sense of obligation. The academic rigour was higher than I thought. My early career involved hands-on problem solving, beginning with fieldwork in Malaysian palm oil plantations. CISL’s PCSB pushed me to connect with studies and frameworks at the forefront of sustainable business thinking; to think at a systems level; and to challenge assumptions. In the best sense of the word, it was cognitively taxing. 

The calibre and diversity of the attendees exceeded my assumptions. The formal and casual peer discussions, who were from different industries and continents, were as beneficial as the course material. It felt urgent and genuine, not academic, to hear how someone from a different industry or nation was battling the same conflicts between commercial demand and sustainability impact.  

CISL’s PCSB is not a programme you undertake simply to enhance your CV. It encourages you to rethink your career, question your assumptions, and redefine your sense of purpose. If you are serious about making sustainability your life's work rather than just a professional label, few places combine Cambridge's academic heritage with CISL's practical sustainability expertise as effectively. 

Can you tell us of a project or initiative where you have applied learnings from the programme? 

One of the most significant applications of CISL’s PCSB learning came through my work at one of the world’s largest palm oil and agribusiness groups, based in Indonesia, where I was involved in a series of initiatives that gradually increased in both complexity and impact. There, the frameworks I developed through the programme became indispensable. The first initiative focused on peatland rehabilitation. 

A highly controversial issue within the palm oil industry, degraded peatlands across the group’s extensive concession areas sat at the intersection of environmental risk, community relations, and corporate reputation. Drawing on the Creating Shared Value framework I had studied during CISL’s PCSB, I helped develop a peatland rehabilitation project that shifted the internal conversation. Rather than framing it solely as a compliance requirement or a reputational exercise, we repositioned peatland rehabilitation as a driver of long-term value creation. In practice, that meant rebuilding the internal business case: instead of treating degraded peat as a liability to be managed at lowest cost, I helped quantify the commercial risk of inaction (eroding market access, exposure to buyer de-listing, and tighter financing conditions) and weighed it against the value that credible restoration could unlock, from preferred-supplier status with sustainability-led buyers to a stronger licence to operate with regulators and local communities. What turned this into a genuine inflexion point was translating that argument into on-the-ground action. The project moved beyond replanting by combining hydrological restoration with community fire-prevention and alternative-livelihood programmes, underpinned by monitoring so we could track and report results rather than simply assert them. Linking those field-level outcomes directly to buyer requirements and traceability commitments moved rehabilitation from a cost centre to a strategic asset and gave us a credible, evidence-based story to present to the world’s most demanding customers. 

That shift in perspective proved transformative. The peatland rehabilitation project became the foundation for key engagements with two global FMCG brands that stand at the forefront sustainability standards. These relationships went beyond transactional supplier agreements; they were collaborative partnerships built on a shared commitment to sustainability. Without the ability to articulate our impact in terms of systemic change and business value, concepts I learned through CISL, it would have been much harder to start and sustain those conversations. 

The project eventually developed into a cross-sector collaboration, Human Rights Due Diligence, which is even more intricate and personally meaningful. The programme's focus on value chain mapping, ethical frameworks, and stakeholder involvement became very pertinent at this point. Human rights due diligence is not a checklist exercise; it requires a sincere understanding of power dynamics within supply chains, the ability to engage with communities respectfully and rigorously, and the credibility to have challenging discussions with both business partners and civil society. CISL prepared me to do that work. 

Looking back on this trajectory, what impressed me most was how each project built on the last—peat restoration paved the way for brand partnerships, which furthered human rights accountability. This applied the Creating Shared Value logic: sustainability as a catalyst for longer-term market access and stronger business connections, not a cost or constraint. In the end, that piece of work completely changed my career path in ways I could not have imagined when I first moved to Cambridge. As a result, I was hired as Head of ESG at Malaysia's oldest venture capital firm. Although this position was in a totally different field, it required the same fundamental skill: arguing that sustainability drives long-term value rather than dragging on returns. 

In that capacity, I oversaw the company's adoption of the UN Principles for Responsible Investment, an important institutional milestone that signalled to the market, portfolio companies, and international investors that ESG was now integral to the company's investment thesis rather than an add-on. Building internal structures, engaging investment committees, and translating sustainability into fiduciary responsibility and risk-adjusted returns were all necessary to achieve UN PRI signatory status. In many respects, it was the clearest manifestation of everything I learned about institutional change and systems thinking at CISL. 

Now, I'm starting what seems to be the most difficult and significant chapter yet: working at Samling to change its sustainable practices in Sarawak, Malaysia. Operating in one of the world's most environmentally and culturally sensitive regions, Samling is one of Sarawak's largest plantation and forestry corporations. Sarawak's forests, which are home to exceptional biodiversity and indigenous populations whose identities, livelihoods, and way of life are inextricably linked to the land, are priceless. The stakes are high. 

In many respects, this position reflects my motivation for joining CISL in 2015. I arrived intending to be more than just a plantation executive with expertise in conservation.  Ten years later, equipped with new frameworks, networks, hard-won experience and the conviction that business and nature need not be at odds, I am working to transform one of Sarawak’s most illustrious natural-resource companies from the inside out. The adventure that began in Cambridge is still well underway. 

How do you feel CISL postgraduate programmes can benefit others? 

Almost every major professional advancement I've made in my career, from plantation executive in Malaysia to peat rehabilitation, Human Rights Due Diligence with international brands, leading ESG transformation at a venture capital firm, founding Social Value Malaysia, and now spearheading institutional sustainability change at Samling in Sarawak, can be traced back to the foundation established at CISL. I don't say that lightly. Therefore, when I consider who would benefit from a CISL programme, I think of a type of individual at a specific moment rather than job titles. 

The practitioner who has reached the ceiling: In 2015, I was that person. I worked with WWF Malaysia's Theory of Change, so I had firsthand knowledge of sustainability. I also understood certification frameworks and conservation science. However, I still couldn't apply that understanding to the language of investment reasoning, corporate strategy, or boardroom decision-making. I got that translation from CISL. Anyone who is truly devoted to sustainability in practice yet frustrated by their incapacity to influence the institutions and systems that ultimately determine outcomes at scale, should check out the programme, in my opinion. 

The business professional who is starting to feel a sense of purpose: Not everyone has a background in conservation when it comes to sustainability. Some of the most influential changemakers I have met come from operational, legal, or financial roles and needed a framework to act on their convictions. CISL is uniquely positioned to meet that need because it invites you to apply commercial rigour differently, rather than giving it up. CISL offers the intellectual foundation and peer support someone inside a corporation needs to confidently make the shift to sustainability. 

The professional in the emerging market who wants to work internationally: this narrative most closely resembles mine.  As a Malaysian working in the highly scrutinised palm oil and plantation sectors, I needed to understand not only the local context but also the global frameworks, expectations and debates shaping market access and relationships with brands. I accessed that world through CISL. Professionals from Southeast Asia, Africa, and other resource-rich countries should consider CISL, as their sectors face some of the world's most significant challenges and should lead the solution rather than just respond. 

The institutional change agent who needs language and credibility: At some point, good intentions aren't enough, whether you work for a government agency, a multinational, a development finance organisation, or a civil society organisation. You need a network that lends you credibility across industries, frameworks that can survive inspection, and arguments that can persuade sceptics. I received all three from CISL, and I have used them frequently, from the Sarawak forest concession to the VC boardroom. I would advise anyone considering CISL to remember it is more than an educational programme. It is an introduction to a way of thinking and a practice community that you will carry with you throughout your professional life. Many people worldwide are concerned about sustainability. But few can function well at the nexus of institutional authority, commerce, and sustainability.  I believe the world urgently needs people like that. CISL helped me develop the integrity and conviction to lead on sustainability for generations to come.

Find out more about our Postgraduate Certificate in Sustainable Business (blended) and other postgraduate programmes.

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