ethy cofounder and Portsmouth graduate Callum smiling at camera with nature backdrop

Co-founder of ethy, a digital solution for sustainable businesses, and Portsmouth graduate, Callum Miller tells us how his company is helping to solve the climate change crisis

5 min read

We’re living in unprecedented times amidst the cost of living crisis. All the while, it’s getting colder and colder, evenings have drawn in and Black Friday is approaching. After all, ‘tis the season to flock to shops (be that in-person or online) and buy, buy, buy ahead of the festive celebrations.

With all of these factors, is it difficult and more expensive to act and shop sustainably? We spoke with 2018 BA (Hons) History graduate, Callum Miller to discuss.

Callum is the co-founder of ethy - a digital solution making it easier for all to shop responsibly whilst helping sustainable businesses. He has teamed up with like-minded people, including a fellow Portsmouth grad - Richard Grethe (BA Hons Accounting, 1994), to achieve the company’s mission. We learnt more about the business helping to create a better world.


So, tell us more about ethy!

32% of shoppers now actively choose brands that demonstrate good sustainability practices, but 80% don’t trust the sustainability claims made by brands and 42% find sustainable shopping too confusing and difficult to do.

ethy is a purpose-led business addressing the above consumer pain points by helping responsible brands communicate their environmental and social commitments in a way that ensures credibility - whilst making it easier for shoppers to make responsible buying decisions!


One of my favourite things about the job is playing an active role in the fight against climate change, which means I can be a part of something bigger than just a business.

Callum Miller, BA (Hons) History, 2018

Through our industry-leading corporate sustainability framework, hundreds of UK brands have been awarded ethy's accreditation, proving their contribution towards the United Nations Sustainable Development Goals and committing to impact transparency.

We then share the complicated topic of sustainability in clear communications that consumers understand and engage with. ethy operates a popular mobile app for sustainable shopping and now, over 10,000 UK shoppers use the free app which offers a resource of accredited sustainable brands, along with how-to guides on sustainable living. Each of these encourages small changes towards a more environmentally and socially considerate lifestyle.

How does it help the environment?

Greenwashing is an unsubstantiated claim to mislead consumers into believing that a company's products or services are environmentally friendly. It’s a real implication for society, by misleading shoppers into acting unsustainably. ethy is on a mission to put an end to greenwashing once and for all by encouraging businesses to prove their sustainability commitments, in turn helping shoppers avoid greenwashing.

Do you think shoppers will compromise on their values this Black Friday given the cost of living crisis? 

There's no doubt that more sustainable products and services can come with larger price tags, and the current situation will mean that many of us can no longer afford to pay this premium. So yes, I do believe the current financial climate will force some UK shoppers to reconsider the products they buy, not only this Black Friday, but in general.

However, I also believe there is a common misconception that shopping sustainably has to be more expensive. But that’s not always the case. When you consider the alternatives, often you’ll find that sustainable products cost more upfront but will save you money over time.

When it comes to sustainability, Black Friday is a controversial topic, especially this year. Many of us are led into buying products we don’t need for the sake of a bargain, generating huge volumes of waste and CO2 emissions. For those who value sustainability, reducing your consumption altogether is one of the best ways to help the environment.

For those who value sustainability, reducing your consumption altogether is one of the best ways to help the environment.

Callum Miller, Co-founder, ethy

Have you always been passionate about sustainability and the environment?

I would say my interest in sustainability started in my early twenties. I always had a strong affinity for the natural world and animals, but it wasn’t until my early twenties that I connected nature with sustainability, and realised that without sustainable development we will lose large portions of the natural world. 

One of my favourite things about the job is playing an active role in the fight against climate change, which means I can be a part of something bigger than just a business.

Tell us about your journey from university to co-founder

I think I’ve always had an essence of entrepreneurial spirit - even from a young age I would think up new ways to improve current practices. The idea of being some sort of inventor was always very appealing!

After university, I took part in a graduate scheme which offered an entry-level opportunity within the business and technology sector. It seemed like a good way to turn my fascination into a potential career. During my three years as a Business Technology Consultant for Sparta Global, I supported really exciting digital projects from modernising National Rail enquiries to developing the Railcard mobile app.

Then equipped with tech experience, I wanted to apply this to something that had more meaning for me. Currently, to me there is no bigger problem than the climate crisis and I wanted to play a small role in solving this problem. I began working on a venture that would help enable this and co-founded ethy in early 2020.

The story so far

Since then, we’ve onboarded hundreds of progressive businesses, built an audience of 20,000+ responsible shoppers, grown to seven employees, raised significant investment and are immensely proud to be using our business as a force for good. In the next five years, we’d like to expand the team with people who believe in our mission. So, if you are a Portsmouth grad and interested, feel free to get in touch

Another goal is for the company to become synonymous with environmentally and socially responsible business practices across the globe. We want to provide consumer assurance that when they choose an accredited brand, they are making a responsible buying decision.

Going from working for someone to working for myself has been amazing. It was a huge weight off my shoulders not having to double up with a full-time job and getting a start-up off the ground. I haven’t looked back once (yet!)

A small world but a bigger alumni community

I was introduced to Richard Grethe, a fellow Portsmouth graduate, through my grandad last year. Not only is he an angel investor, but he is also a fundamental part of the team and totally behind our mission. As an experienced business person and entrepreneur, he is helping us navigate the many challenges we face as a startup while leveraging his network to accelerate our growth. His mentorship for me personally has also been invaluable as a source of clarity on issues, as well as encouragement.

What advice would you offer to budding entrepreneurs?

Most people will tell you to go ahead and start the business. My advice would be unless you are 100% sure about entrepreneurship, there’s no harm in getting a job out of university before you make the leap. This will buy you some more time, ensure financial stability and enable you to develop important skills that you can apply to a potential business in the future. If a year or so down the line entrepreneurship is still calling your name, then go for it. You’ll be better equipped to make a success of it.