What Sustainable Chemistry Actually Means with Professor Tom Welton

What does sustainable chemistry really mean and why does it matter far beyond the lab?

In this episode of Clear Haze Exchange, Marcus Hazelwood speaks with Professor Tom Welton, OBE, Emeritus Professor of Sustainable Chemistry at Imperial College London and the world’s first professor of sustainable chemistry.

Professor Welton shares how sustainable chemistry evolved as both a field and a mindset, why the gap between theory and application is often larger than people expect, and how words like green and sustainable can sometimes mislead more than they clarify.

This conversation explores the hidden systems behind sustainable science and innovation, including product development, lifecycle analysis, behavior change, research incentives, and the long road from lab discovery to real-world deployment.

In this episode, we discuss:

• The difference between green chemistry and sustainable chemistry
• Why sustainability is often best understood as a mindset
• How “green” ideas can fail under operational or financial pressure
• Why life cycle analysis matters when evaluating products and materials
• What universities get right, and wrong, about innovation
• Why sustainable technologies often take decades to scale
• What gives hope for the future of sustainability in science and education

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What is Clear Haze Exchange?

Clear Haze Exchange is an interview-led podcast focused on simplifying sustainability while uncovering the hidden systems, decisions, and long-term impacts shaping our built environment and energy future.

Hosted by Marcus Hazelwood, an energy engineer with 15+ years of experience in sustainability and energy efficiency consulting, the podcast has evolved across two seasons:

Season 1 focused on breaking down the fundamentals—making energy efficiency, building systems, and sustainability concepts more accessible and practical for a wide range of listeners.
Season 2 builds on that foundation, diving deeper into the systems-level thinking behind sustainability—exploring how decisions in design, operations, policy, and business strategy create long-term outcomes.

Each episode features thoughtful conversations with industry leaders, engineers, architects, researchers, and decision-makers who are actively shaping the future of sustainability. From building performance and infrastructure to sustainable chemistry and organizational mindset, Clear Haze Exchange connects ideas across disciplines to provide real-world insight.

This podcast is for professionals and curious minds alike, those who want to better understand not just what sustainability is, but how it actually works in practice.

If you're interested in smarter investments, better systems, and meaningful progress, you're in the right place.

Subscribe to Clear Haze Exchange on your favorite platform and join the conversation.

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