Our purpose

Better carbon markets

What we do

Quality & impact ratings for carbon credits

Carbon credits are based on trust – that each credit represents one metric ton of removed or reduced emissions and that co-benefit claims are real.

Calyx Global independently assesses the greenhouse gas integrity and Sustainable Development Goal impact of carbon credits.

Our ratings are comprehensive, covering multiple project types, including nature, renewable energy, waste, chemical processes, household & community and others.

GHG Ratings

Calyx Global’s greenhouse gas (GHG) integrity ratings assess the likelihood that carbon credits truly meet their CO2 reduction or removal claim.

SDG Ratings

Our Sustainable Development Goal (SDG) impact ratings provide information on the quality of certifications used to claim SDG impacts. We also rate project claims of specific SDG contributions.

What we offer

For buyers of carbon credits

Calyx Global ratings empower you to make more informed decisions about carbon credits.

With our ratings, you can screen and compare individual projects or portfolios, weigh the merits and risks of different project types and methodologies and ask better questions as you make decisions.

Calyx Global ratings help buyers who care about having more impact.

For brokers, marketplaces and exchanges

Buyers want a quality lens before buying a credit or using it as an offset.

By integrating Calyx Global ratings into your platform, you can provide differentiation on quality and impact for credits on offer.

APIs and other tools can connect your customers to independent insight about credits you offer.

Why Calyx


Calyx Global ratings are based on years of experience in carbon markets and methodologies.


Systematic application of our frameworks leads to comparability across projects and methodologies.

No conflict

We don’t benefit financially from higher ratings, and we don’t buy or sell credits.

Founding team

Donna Lee

Donna has worked on climate change for 17 years. She has lived in the Colorado Rockies for the past 10 years and spends her winter weekends shoveling snow. Living at 10,200 ft also means she sees the effects of climate change up close. Her goal in life aligns with Calyx's mission: to contribute to the well-being of people and to protect the planet. Donna has a B.S. in Electrical Engineering and a Masters in Education from UCLA, and a Masters in International Policy from Stanford University.

Duncan van Bergen

Duncan set up and led a leading nature-based carbon project development business and worked in energy before that. Duncan is a passionate runner and reader. He cares deeply about ecosystem preservation and aligning societal and economic development with that. Duncan has degrees in economics and management from the University of Louvain and the Solvay Business School and an MBA from the Harvard Business School.

How can we help?

We are designing products and solutions to help you make quality decisions in carbon markets.

Let’s explore how we can help you.