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Who We Are

We are a global consulting firm that empowers businesses to strive towards being environmentally conscious and socially responsible within a circular economy. 


Based in Chicago and The Hague, we foster collaboration towards the integration of sustainable business practices and policies that are needed to address global issues like climate change and human rights.

Circularity - noun

the state or quality of moving or occurring in a cycle.

While sustainability acts as an umbrella to every practice that strives to sustain the future, circularity is more about the practices which lead to sustainability.

Why choose us:

  • We are trusted to teach best practices for integrating sustainability into business strategies.

  • Our reporting services follow global frameworks and standards such as as Science Based Target Initiative (SBTi), Global Reporting Initiative (GRI), Corporate Social Responsibility Directive(CSRD)

  • We aim to adhere to the UN Guiding Principles.

  • The health and well-being of our clients and partners is central to our functioning

Meet Our Founder

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Tannis Williamson

Founder & Managing Director 

Tannis Williamson is the Founder & Managing Director of The Sustainability Firm. Tannis has spent two decades making an impact in the fields of philanthropy and sustainability in Europe and the US. In 2017, she established The Sustainability Firm to bring together businesses, NGOs and governmental agencies to implement strategies and initiatives needed to achieve the targets set out in the Paris Climate Agreement and the UN Sustainable Development Goals.

Tannis holds a Masters in Entrepreneurship and Innovation from the University of Luxembourg, a Masters in Public Administration from Illinois Institute of Technology and a Bachelors in Criminal Justice from Clark Atlanta, University.

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Work with Us

Ready to take the next step towards a more sustainable future? Contact us today to discuss how we can work with you to drive positive change and create a shared value for your business. 

Services of Interest:

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