What does it take to create a successful start-up? This International Women’s Day we find out from the female entrepreneurs leading by example

This International Women’s Day, we at BlueSky Thinking are celebrating the inspiring female entrepreneurs who have used their business school education to create their own career paths.

Drawing on what they’ve learned through business education, and their professional lives following graduation, they share their advice for other women aspiring to follow in their footsteps, sharing their ideas, inspirations and ambitions for the future.

For Johanna Broell, co-founder and CEO of Carbonsate, fortitude has been an invaluable quality in crafting her vision into a resilient, rapidly growing venture. “Every rejection is valuable information,” she shares. “Internalising that mindset changed everything. Each “no” clarified the strategy. Each critical question strengthened the business model narrative. Over time, resilience stopped being a reaction to difficulty and became a core capability.”

Johanna’s mindest is vital for propel Carbonsate to reach its goal of removing more than ten million tons of CO2 from the atmosphere every year by 2033.

Here she shares how her the lessons learned from her career and her time spent on the Executive MBA at Mannheim Business School have helped her on her journey.

Please introduce yourself to our readers – who are you and what is your job role?

I am Johanna Broell, an impact entrepreneur and co-founder of Carbonsate. My work is driven by one clear conviction: reaching net zero requires more than reducing emissions. It requires removing carbon that is already in the atmosphere. 

At Carbonsate, I lead the strategic vision and growth of the company. My role spans long-term strategy, partnerships and capital formation, alongside the responsibility of shaping a purpose-driven organisation rooted in scientific integrity and measurable impact. For me, entrepreneurship means taking responsibility for solutions that truly matter. 

What does your start-up do?

Carbonsate turns waste wood into durable carbon removal. Our approach is called biomass storage. Trees naturally capture carbon dioxide as they grow and store the carbon in their biomass. Using engineered storage conditions and rigorous monitoring, we ensure that this carbon does not return to the atmosphere. 

In doing so, we are building the foundation for affordable, globally scalable carbon removal that supports the transition to a net-zero economy. Our projects already operate internationally, including in Namibia, where we work with local partners on large-scale biomass storage. 

Tell us about your background – where did you grow up?

I grew up in the former German Democratic Republic (GDR) and experienced the transition between two fundamentally different economic systems at a young age. That early exposure sparked a lasting fascination with how economies function, how incentives shape behaviour, and how systems influence individual opportunity. 

Entrepreneurship was not something that existed in my immediate environment. My surroundings were shaped by political and economic upheaval, and stability was valued over risk. Still, I always felt drawn to understanding business and taking responsibility. 

I studied business administration and went on to build a corporate career in international leadership roles in finance and procurement. From early on, I was motivated by impact and responsibility, and I sought positions where I could shape decisions rather than simply execute them. 

What were your early career ambitions and experiences? How have they contributed to where you find yourself now?

Early in my career, I was driven by a strong desire to take responsibility and understand how organisations truly function. I chose a corporate path because I wanted to learn the fundamentals of business from the ground up. 

In international leadership roles in finance and procurement, I gained a solid foundation in strategic decision-making and organisational dynamics. I learned how structures influence behaviour, how incentives shape performance, and how much leadership clarity matters in practice. Over time, I also developed resilience and a deep appreciation for the human side of organisations. Results are rarely driven by strategy alone. They are driven by people who feel ownership and direction. 

“The world needs more women in positions of responsibility and more women building companies. Diverse leadership is not a symbolic goal. It changes how decisions are made and which priorities are set in our society.”

– Johanna Broell

One insight became particularly important to me: when purpose is clear and tangible, people align and move forward with energy. When it is abstract or disconnected from daily work, motivation fades. That understanding has strongly shaped how I think about leadership today and how I chose to build my own company. 

What was the reason you decided to go to business school? What was it about your school and programme that encouraged you to enrol?

I decided to pursue an Executive MBA because I felt there was more I wanted to achieve. I had a strong ambition to grow into larger leadership responsibilities and to operate at a higher level of impact. I saw the programme as an opportunity to sharpen my thinking, broaden my perspective, and strengthen the foundation for the next stage of my career. 

Mannheim Business School attracted me because of its reputation for academic excellence and its international focus. If I was going to invest in such a demanding programme, I wanted to learn among people who were equally ambitious and accomplished. Being surrounded by high-performing peers was important to me. I wanted to challenge myself and learn from the best. 

What I did not anticipate was how much the programme would broaden my understanding of impact. Until then, I had equated responsibility with climbing the corporate ladder. The MBA exposed me to entrepreneurship as a different and equally powerful route to creating meaningful change. That shift in perspective proved decisive. 

What was the most valuable take-away from your studies?

The most valuable take-away from the programme was not a specific framework or theory. It was the experience of being pushed to my limits and realising that I could go further than I had assumed. 

The intensity of the programme challenged me intellectually and personally. Navigating demanding coursework alongside a full-time leadership role required discipline, resilience and focus. Over time, I developed a deeper confidence in my own capabilities. I learned that I can operate under pressure, absorb complexity, and still make sound decisions. 

That confidence became a turning point. It gave me the courage to consider paths that had previously felt out of reach. Entrepreneurship moved from being an abstract idea to a realistic option. It is very possible that I would not have started my own company without this experience. 

What inspired you to start your business?

At a certain point in my corporate career, I realised that the next step upward was no longer what I was looking for. I was not searching for a bigger title. I was searching for a bigger problem to work on. I wanted to contribute to something significant and urgent. 

Climate change emerged as the defining challenge of our time. I asked myself where I could create the greatest contribution with the skills and experience I had built over the years, and how I could align my professional path with my personal values. 

“For me, entrepreneurship means taking responsibility for solutions that truly matter.”

– Johanna Broell

Founding a climate-focused company became the logical consequence. It allowed me to combine economic thinking with societal responsibility and to direct my capabilities toward a challenge of global relevance. In that moment, my ambition and my values moved in the same direction. 

How did your business school/education support you in realising your entrepreneurial ambitions?

The programme gave me a strong foundation and, equally important, the confidence to act on it. It helped me translate experience into structured thinking and long-term decisions. 

Beyond the classroom, the network has been particularly valuable. I remain actively connected to Mannheim Business School, take part in events, and share my entrepreneurial journey with current and prospective participants. I value the exchange across the community, from future participants to fellow alumni at different stages of their careers. 

Being part of this community has supported my entrepreneurial path in practical ways, through visibility, credibility and trusted relationships. I also see it as a responsibility to give back to a network that continues to be part of my professional environment. 

What were some of the biggest challenges you faced in the early stages of building your business, and how did you overcome them?

One of the biggest challenges in the early stages was operating under constant uncertainty while entering a field that was entirely new to me. Building a company in carbon removal required learning at high speed across science, regulation, financing and market development, while at the same time creating a viable business structure. 

The intensity came from the simultaneity of everything. Multiple workstreams moved forward in parallel, and early concepts were often rejected. Securing investors required persistence over many months, repeated conversations and continuous refinement of our positioning. 

The most important lesson was this: every rejection is valuable information. Internalising that mindset changed everything. Each “no” clarified the strategy. Each critical question strengthened the business model narrative. Over time, resilience stopped being a reaction to difficulty and became a core capability. 

As a female entrepreneur, have you encountered any obstacles or biases in your entrepreneurial journey? How did you navigate them?

I have always seen myself as a founder first, not as a “female founder”. My focus has consistently been on building a solid business and delivering impact. 

At the same time, certain patterns became visible in investor conversations. In some cases, particularly with male investors, discussions centred heavily on validating my business competence and risk awareness before moving to vision and growth. Given my professional background and education, this dynamic was surprising to me at first. My impression is that male founders may experience a different starting point in similar conversations. 

Over time, I learned to navigate this consciously. Today, I briefly address critical questions with clarity and depth, and then actively steer the discussion toward strategy, ambition and long-term value creation. Rather than allowing the dynamic to define the conversation, I choose to shape it.

What advice would you give to other women who are considering starting their own businesses? Is there anything you wished someone had told you as you began your entrepreneurial journey?

The world needs more women in positions of responsibility and more women building companies. Diverse leadership is not a symbolic goal. It changes how decisions are made and which priorities are set in our society. 

Many women are conditioned to overprepare and to justify their seat at the table through exceptional performance. I recognise that pattern. My advice would be to grant yourself permission earlier. You do not need to be perfect before you begin. Competence grows through action, not overthinking. 

Start before you feel fully ready. Learn while moving. Surround yourself with people who challenge and support you. Confidence rarely comes first. It grows as you move forward.

Where do you see yourself in five years?

In five years, I see Carbonsate operating at scale and contributing millions of tonnes of durable carbon removal. Building climate infrastructure that is both credible and affordable remains the ambition. 

Beyond metrics, I see myself continuing to work on large, system-level challenges. I am motivated by problems that require both economic thinking and societal responsibility. That will not change. 

What matters most to me is direction. As long as my work aligns ambition with impact, I will know I am exactly where I should be. I am still learning every day, and I expect that to remain true. 

Find out more about Johanna via LinkedIn, and her work with Carbonsate via the website.

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