High-impact, nature-based climate solutions lack the substantial financing needed today to scale climate mitigation. Callirius is the bridge between finance and climate.  We finance high-quality climate solutions through a data-driven, science-backed, and regulated framework.

Explore our solutions

We favour nature-based solutions at Callirius. They are the only scalable and economically viable solution today for the active removal of CO2. They are the only solution to additionally restore and protect nature and biodiversity effectively and efficiently. Every climate project in our portfolio conforms to our Callirius Quality Framework.

These are the natural ecosystems we work with: 



Wetlands are essential for local biodiversity and the future of our climate. They are one of the few land-based ways to permanently store carbon. Our wetland projects include peatland rewetting and mangrove forest protection. These sensitive ecosystems not only prevent future CO2 emissions, but also capture additional CO2 from the atmosphere.

Soil and Agriculture

Soil & Agriculture

More carbon is stored in soil than in all aboveground plants. Through land modification strategies, we can alter the global carbon cycle by increasing the soil’s organic carbon stocks and biomass production. We also use soil management strategies to increase carbon concentrations in the soil.



We all know trees pull in carbon for photosynthesis, taking it out of our atmosphere, and storing it for the life of the tree. Our solutions include reforestation and afforestation, as well as enhanced forest management practices. Creating forests that are resilient, adaptable, biodiverse, and carbon-rich.



The ocean is a massive carbon sink, sequestering 40% of the carbon emitted through fossil fuel burning since the industrial revolution. We work to protect the seafloor and increase biomass in the ocean through alkalisation and fertilisation. The ocean is an essential tool in mitigating the climate crisis.

Meet our team​

The Callirius team uniquely brings together over 100 years of experience in the finance and banking sector. This enables us to create tailor-made financing solutions through a data-driven, science-backed, and well-regulated framework.

Ebrahim Attarzadeh

Co-founder, CEO & Chairman

After more than 20 years in Investment Banking in various leading positions, latest as CEO of Stifel Europe Bank/Mainfirst Bank, I decided to actively contribute to solving our biggest challenge: climate change. Outside work you find me doing watersports, skiing and sharing time with my three boys.

Rudolf Maier

Co-founder, Head of Distribution

I have been an investment banker for more than 25 years, and now it was time for a change. I couldn't be more excited to start a new episode in the space of green and sustainable assets with my friends and former colleagues. I love to see my 2 boys growing and hope they have the opportunity to enjoy our wonderful planet as much as I do.

Michael Grohmann

Co-founder, Head of Project & Policy

If you can combine the skills learned from 20 years in banking and the passion for nature to fight climate change, it is not only a privilege but also a duty. I want to contribute to shaping a sustainable and liveable future for our kids.

Tim Schuldt

Co-founder, Head of Product & Technology

I am an ex-Banker with a passion for programming and decentralised ledger technology, helping the world in its fight against climate change by combining my technological and financial know-how.

Dr. Ulrich Franke

Financing Solutions & Advisory

Asset-Backed Financing has always been my professional focus. Therefore, I am supporting Callirius and the community to find ways to combine the concept of secured financing with an understanding of nature as an asset in order to create Nature-Backed Financings.

I am a management engineer, with experience as a business strategist and consultant in the Financial industry. I am determined to bring Climate Finance into effective urgent action to add constructive value to global society. Outside the office you can likely find me in the mountains, enjoying live music, between the cookers or on my yoga mat.

David Steinmetz

Natural Climate Solutions Specialist P&P

I am an environmental scientist with a background in economic geography. I want to contribute to a sustainable future by helping to implement impactful climate solutions. In my spare time I can be found hiking in the mountains or playing roundnet.

Jonas Landgraf

Product Specialist

After working in banking and e-commerce, I realised we are heading towards a cliff and it is time to build a bridge towards a sustainable future, both for us and the next generations. I am proud to take active part in climate action. In my spare time, you can find me playing beach volleyball, skiing and spending time in the beautiful little forest next to my home.

James Boilson

Head of Business Intelligence

My focus for the last 20 years has been on Business Intelligence. I have founded, grown and exited two tech companies. Recognising the scale and urgency of the climate change challenge, I wish to contribute to a sustainable future by supporting Callirius to leverage their unique platform to help implement impactful solutions for the next generation.

Help us enable more effective decarbonization by joining our team and living our mission! 

As we believe the right talent can come unexpectedly, we accept applications on a continuous basis


Callirius means “king of the wood” in Roman Britain. Taking care of woodlands plays a key role in reducing our carbon footprint, meeting the 1.5°C targets, and fighting climate change.

Meet our advisory board​

With expertise combining science, project know-how, and market insights, our advisory board brings together an abundance of knowledge around the lifecycle of carbon credits.

I am Professor of Corporate Management at the University of Trier. I am a research and teaching expert in innovation and sustainability management of SME companies, in particular in the decarbonization of industrial SMEs.

I am a founding partner of Lucy Capital, an early stage VC investing in ClimateTech, Health and People Empowerment. Before I founded thriving ventures in travel and fashion. I also worked in the successful development of Zalando and some of its portfolio companies and as a PE restructuring manager.

I have worked as head of marketing at MyClimate, a Swiss-based NGO focusing on climate protection and sustainability measures. I am an expert in communications and sustainability. I am also a football aficionado and a passionate hiker.

Come and join our team

If you have expertise in climate finance, climate science or carbon markets or are a professional climate enthusiast, we welcome applications on a continuing basis.

Contact us