Celest.Science is a climate tech startup that helps businesses anticipate and manage climate risks, using AI-powered models to turn complex environmental data into clear, actionable insights. Their predictions equip decision-makers with critical information, helping them strengthen operational resilience, plan strategically, and support sustainability across sectors like agriculture, energy, and finance.
To accelerate its research and go-to-market strategy, the company recently raised €2 million, including over €500,000 from individual investors and business angels, pooled in a dedicated SPV managed through Roundtable.
With Roundtable handling the SPV setup, investor onboarding, and the related operational and administrative tasks, the process was smooth, fast, and efficient. This enabled the team to focus on attracting the right investors: people with deep sector expertise, valuable networks, and hands-on entrepreneurial experience.
Co-founder and CEO Léo Lemordant shares how the fundraising process unfolded – and why using an SPV with Roundtable made all the difference.
Key takeaways:
- Thanks to Roundtable’s SPV structure, all investors were grouped into a single vehicle, thus simplifying governance, reducing operational overhead, and creating a neutral, trusted framework for everyone involved. This streamlined setup enabled Celest.Science to onboard more investors at no extra effort, which helped bring in a variety of profiles, expertise, and perspectives.
- Roundtable’s SPV made the entire process smooth and efficient, making it very easy for business angels to invest, even in the case of last-minute commitments, and bringing real economies of scale.
- Roundtable is handling all the operational and admin work of managing the SPV, from the legal legwork to payments, accounting, and investor reporting. This allowed Léo and the team to stay focused on what matters most: selecting the right investors and building the business.
Roundtable: Could you introduce Celest.Science and its mission?
Léo Lemordant: We founded Celest.Science two years ago to help businesses better understand and anticipate climate risks, from a couple of weeks to several years ahead.
For that, we leverage a wide range of data: weather conditions, snowfall levels over the winter, soil moisture, and more – to estimate the probability of extreme events, such as heatwaves, floods, and droughts.
The goal is to give risk managers, especially in sectors like insurance, the insights they need to assess their true exposure to risk and adapt their operations.
Unlike traditional weather forecasts, our models are probabilistic. They can, for instance, estimate that there’s a 15 to 20% chance of an event happening this year, even if historically it has only occurred 1% of the time in history. That ability to anticipate is what makes our models valuable.
Doing so requires to unveil the physical links behind events. Explainable AI enables us to do so, which is specifically relevant for parametric insurance and an assessment of compound events that are totally overlooked in the industry right because of the lack of relevant tools.
Celest.science is the result of a collaboration between myself and Pierre Gentine, my former PhD advisor– earlier in my career, I completed a PhD at Columbia University in New York City, focusing on heatwaves and the interactions between carbon and water cycles. After my PhD I did not pursue an academic career but instead cofounded a first startup. I remained CEO during 8 years, until my successful exit in 2022.
As for my co-founder, he has become an internationally recognised expert in applying artificial intelligence to climate science. He has founded a research centre at Columbia, with a $25 million budget, entirely dedicated to using machine learning to improve climate models and was even cited by the Nobel Committee for Physics in 2024 for his work in the field.
Together, our mission is to bridge this cutting-edge research and the operational needs of businesses. We want to make these technologies accessible, practical, and valuable for managing climate-related economic risks.
Roundtable: Can you tell us about your fundraising journey – and Roundtable’s role in it?
Léo Lemordant: At first, we operated for 18 months without raising any external capital. We financed this initial phase using our own funds as founders, along with a first client contract we signed with Zurich Insurance Group.
This allowed us to build our AI engineering team and develop the first iteration of our technology.
Then, at the end of 2024, we carried out a funding round to accelerate our go-to-market.
This round involved different types of investors:
- An SPV managed by Roundtable, pooling together about fifteen business angels
- Three separate investment vehicles: Plug and Play, Astorya.vc (a fund specialised in insurtech), and the Climate Club, a business angel group focused on climate tech.
In total, we raised a €2 million round, and the SPV managed through Roundtable accounts for over €500,000.
Ticket sizes in the SPV were very diverse, ranging from €10,000 to several hundred thousands euros – and we’re really happy with the profiles of the investors who joined us. They include:
- Stéphane Guinet, CEO of Kamet Ventures and former member of AXA’s executive committee
- Didier Valet, associate founder of Varsity.vc and former deputy CEO of Société Générale
- Christophe Neves, Chief Risk Officer at Skyline, previously at AIG
- Éric Mignot, CEO and co-founder of +Simple
- Armando Mann, former executive at Dropbox et Google
- Several business angels with expertise in climate risk, insurance, or entrepreneurs from the insurtech and risk management space.
Roundtable: Can you tell us a bit more about your experience working with Roundtable?
Léo Lemordant: Before founding celest.science, I had created Enerfip in 2014, a crowdfunding platform for renewable energy projects, which I sold in 2022. At Enerfip, we used SPVs extensively to finance solar and wind projects – at one point, I was president of about 25 vehicles.
So, the SPV is a model I’m deeply familiar with, which means that we could have managed it directly, either by ourselves or with the help of our accountant.
But what’s great about working with Roundtable is that it removes all the governance complexity of managing your own SPV. If you do it yourself, you have to run the vehicle, manage potential conflicts of interest, deal with regulatory issues, and so on. Having an independent third party handle all that makes things much simpler and builds trust between all parties involved.
Beyond governance, there’s also all the operational admin work. Running an SPV means managing accounting, fund flows, payment reminders, investor reporting, etc. With Roundtable, all of that is done for you. It makes the whole process so much smoother and more efficient, with real economies of scale.
Roundtable: What were some of Roundtable’s operational benefits that had the biggest impact on your fundraising?
Léo Lemordant: What really stood out to us was how smooth the investor onboarding process was. We had some late-stage commitments, very close to the closing date I’d initially planned, but despite the tight deadlines, the whole process was fast and effortless.
This allowed us to finalise the SPV very quickly, which wasn’t a given, especially compared to my prior experience – in the past, collecting funds from multiple investors could sometimes be a pain point. With Roundtable, it was extremely efficient.
Roundtable: How about the challenges, though? What was the biggest challenge in this fundraising round?
Léo Lemordant: The main challenge wasn’t so much finding people who want to invest in Celest.Science, it was choosing the right ones.
The key is to bring in people who can really add value, both now and in the long run. People you want to work with, spend time with, and partner with. That’s really the heart of it.
Roundtable: When you say "people who can add value", what does that mean for you, more specifically?
Léo Lemordant: It can mean a few things, really:
- Access to relevant networks
- Sector expertise that’s directly useful to us and our mission
- Entrepreneurial experience from people who’ve built companies before, who can spot weak or strong signals, challenge me on certain topics, or give me advice
This type of entrepreneurial experience is super valuable when preparing for future fundraising rounds – investors who’ve already been through those stages can share best practices and lessons learned.
Beyond that, we also needed advice on how to structure the company. Even though I’ve already built and scaled another business successfully, every company is different. Celest.Science is a very specific project, with a deep tech DNA and a development rhythm that’s shaped by research. That’s where our investors add real value, helping us adapt our structure, processes, and ways of working as we scale.
Roundtable: Do you feel like the SPV helped you attract the right kind of investors?
Léo Lemordant: Yes, definitely. Without an SPV, I probably wouldn’t have brought 15 investors around the table. I might have gone for 4 or 5 at most, and even that can already be quite complex to manage.
But with an SPV, governance is much simpler, so you can afford to multiply the profiles, expertise, and perspectives. And that brings incredible richness to the project.
Roundtable: Are most of the investors based in France?
Léo Lemordant: Yes, within the SPV managed by Roundtable, all the investors were French. But in the overall round, we also had an American investor and a German one, via the Plug and Play fund, which is based in Germany. That’s important for us because our market is clearly global, and international expansion is a clear goal for us from day one.
Roundtable: How was your own onboarding experience on the platform?
Léo Lemordant: Super straightforward. I was already an investor myself on other Roundtable deals, as a business angel, so I was already familiar with the tool. This time, I was just switching roles, from investor to entrepreneur.
Roundtable: Do you consider this fundraising round a success?
Léo Lemordant: Yes, absolutely. We raised exactly the amount we were targeting, and in fact, we were slightly oversubscribed, which meant we could be selective about the investors we brought on board.
We’ve managed to build an investor pool that brings a lot of value and is very aligned with our challenges and ambitions.
Roundtable: Let’s talk about the future of Celest.Science. What will this funding round enable you to do? What are your next priorities?
Léo Lemordant: Before the fundraising, we had mainly built the core technology. The next step is about bringing that tech to commercial life: building the interface, industrialising our models, and turning what we developed in R&D into a full solution that can be deployed to many customers. In short, accelerating our go-to-market strategy.
We’re starting to roll out our products, mainly in the insurance sector (which is our top priority), but also in the energy sector. Those are the two verticals we’re currently focusing on.
Roundtable: And lastly, what advice would you give to other founders who are at a similar stage, whether it’s about fundraising in general or your experience with Roundtable?
Léo Lemordant: I’d say: “Hang in there, especially if it’s your first fundraising round”. It’s a real mental challenge. You have to be ready to learn a lot of new things – the legal aspects of fundraising, negotiation tactics, deal structuring, and more.
Fundraising is a demanding process, but also a very rewarding one. You step into a whole new world, you meet a lot of people, and obviously, success is a huge milestone for any project.
Using a platform like Roundtable really helps a lot, particularly when it comes to all the administrative and legal work. It allows founders to focus on what really matters: their project, discussions with investors, and the overall strategy.
Roundtable: Would you consider using Roundtable for future fundraising rounds?
Léo Lemordant: Yes, without a doubt – if it fits the context and our specific needs.
If it’s a round made up entirely of VC funds, it might not make sense. But if we’re looking to syndicate business angels or structure a new SPV, Roundtable is definitely a great option. And I’m sure they’ll continue to expand their offering to fit many different scenarios.
{{clients_banner}}
