About Leaf

Explore Tomorrow

Our mission and vision

Leaf runs courses that prepare and support exceptional teenagers to have a positive impact at university and with their career. Through our courses and community students:

  • Engage deeply with big ideas and real-world challenges

  • Make informed academic and career choices

  • Build sustainable habits for long-term positive impact

  • Find peers and mentors who make learning - and life - more meaningful

Our philosophy

We identify and support exceptional young people with the potential to do extraordinary good. Our courses challenge students to think deeply, reason clearly, and act ambitiously. By bringing them together in selective cohorts, we aim to foster a community where they inspire and push each other toward lives of meaning and positive impact.

We are inspired by and have roots in recent movements like effective altruism and moral ambition, but we don’t treat any single philosophy as dogma. Instead, we encourage students to wrestle with hard questions: How can we best use our talents to improve the world? Which problems are most urgent? Where are we most likely to be wrong? We want participants to engage critically, not just adopt a set of ready-made answers.

Our courses are not just about learning ideas in the abstract. We push students to test them, critique them, and turn them into projects, passions, and careers that matter. Our alumni go on to pursue impactful research, tackle pressing global problems, advocate for positive change in their local and global communities, and build organizations of their own.

We select course participants carefully to make our core programs as impactful as possible with the resources we have available. At the same time, we strive to build a wider community where every altruistic teenager can find support, inspiration, and a place to belong, and therefore offer our online courses and community for free to all applicants.

Ultimately, we want every participant to discover meaningful opportunities to do good, and the skills and community to act on them.

Our funding

Logo of Carina with stylized molecule icon in blue, pink, and purple next to the word 'carina' in dark blue

Leaf is a US-registered 501(c)(3) non-profit organization. Through our sliding tuition donation model, guardians of our participants contribute to our mission through flexible tiers, including full free access for any student who needs it. Our admissions are entirely merit-based without any consideration of ability to pay.

We cover the remainder of our expenses - which primarily come from hiring top talent to our committed facilitation staff - comes from Carina Initiatives, whose mission is to “send more kids from more communities to the frontiers of science and technology.”

Previously, much of our funding came from from the Effective Altruism Infrastructure Fund. They provide support for projects and charities ranging from healthcare in the Global South, to advocacy for animal welfare reforms, to research into ways to develop safe artificial intelligence. 

Our team

  • A smiling young man with short brown hair and a beard, wearing a pinkish-red button-up shirt, sitting in an office environment with a computer and other office supplies in the background.

    Jonah Boucher - Managing Director

    Jonah is a teacher and curriculum designer in the US. He has supported and led projects to help talented and passionate high school and college students lead impactful and fulfilling lives. Jonah recently graduated from the Harvard Graduate School of Education and previously came first in his class (of over 500) at Hamilton College with degrees in Mathematics and Environmental Science.

  • Young person with long hair that is brown at the top and red at the tips, smiling at the camera indoors with shelves of comic books or graphic novels in the background.

    Sam Smith - Head of Courses

    Sam is a 3rd Year Maths and Philosophy Student at University of Bristol, EA Bristol President, experienced Non-Trivial facilitator, and a proud Leaf alumni from our early residential programme days! Their specialty is helping people discover and fulfill their potential to make meaningful impact to ensure AI goes well for humanity.

  • A young woman with long brown hair smiling, standing outdoors near water with rocks and houses in the background, wearing a colorful fleece jacket.

    Claire MacDonald - Safeguarding Lead

    Claire studied philosophy at Durham University and completed an exchange year at De Rijksuniversiteit Groningen in the Netherlands, where she became an editor and author of the magazine Qualia. She works part-time helping support and empower people with learning disabilities and autism. She was also a Student Ambassador for Durham Uni and Welfare Officer for EA Durham.

  • A woman smiling in a red coat and scarf at an outdoor event during the holiday season with Christmas lights and festive decorations.

    Hannah Rowberry - Uni Admissions Support

    Hannah has a first class degree in natural sciences and a PGCE in secondary education, both from the University of Cambridge. After a few years in teaching, Hannah worked as an admissions and access officer at three Oxford colleges — Christ Church, Exeter, and Lady Margaret Hall — and now works as an admissions consultant.

Each course is also supported by uni. student alumni facilitators, and expert mentors and speakers. Not all staff are listed on our site!

Board of Directors

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    Rebekah Blume

    Director

    Rebekah is a mixed-methods evaluation consultant with deep experience helping nonprofits generate insight and learn from their impact. She also works with Effective Thesis, helping measure the long-term impact of research guidance programs for early-career scholars. Rebekah’s thoughtful, systems-aware approach to organizational learning will be instrumental as Leaf sharpens its impact evaluation and supports the next generation of high-impact leaders.

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    Jamie Harris

    President

    Jamie is the Courses Project Lead at the Centre for Effective Altruism, where he designs and runs online programmes that empower talented professionals to explore how they can do the most good. He also serves as a fund manager at the Effective Altruism Infrastructure Fund, supporting promising projects with access to capital, talent, and strategic insight. Jamie directed Leaf for four years and previously worked as a teacher, researcher, and program builder across multiple high-impact organizations, including Macroscopic Ventures, Sentience Institute, and Animal Advocacy Careers.

  • Portrait of a smiling woman with shoulder-length brown hair, wearing a black turtleneck and gold hoop earrings, standing outside in front of a building.

    Joy Wiersum

    Director

    Joy is an impact and leadership strategist with nearly two decades of experience accelerating growth and shaping leadership. She has led senior growth and organizational design efforts at the WHO Academy, shaped board and CEO transitions as an advisor at Russell Reynolds Associates, and now provides strategic and leadership support to mission-driven organizations worldwide. Her expertise spans scale-up strategy, leadership development, and cross-sector collaboration, making her an invaluable guide as Leaf grows its global presence and long-term impact.