Meet Our Team
Celeste Blackman, Co-Founder of Green Zone Culture Group
Celeste is an international consultant and co-founder of the Green Zone Culture Group, dedicated to creating organizational cultures where high trust, emotional commitment and collaboration thrive. For over 20 years, Celeste's focus has been on the human side of business, helping leaders and managers create better working environments, Green Zones. Green Zone work environments are characterized by open and effective communication, accountability and cooperation. It is in these environments that human energy soars, employees care about their work and each other, people connect with one another and cooperate to achieve extraordinary results.
Celeste is dedicated to reducing fear and defensiveness in the workplace, the underlying cause of most of the human problems in organizations. She helps leaders and managers achieve this by combining the best of behavioral science and experiential learning to help people develop the skills, the attitude and mindset for building strong relationships. She has a special interest in the emerging fields of neuroleadership and neurobiology. Collaboration with neuroscience researchers has led to training experiences that are brain-friendly, thereby accelerating personal growth and organizational effectiveness.
Celeste has worked with a wide range of clients including NASA, The Human Element Sweden, Chevron, Idaho Power, Business Consultants of Japan, The United Nations, the National Institutes of Health and the National Cancer Institute. A certified Marshall Goldsmith coach, Celeste has been coaching clients regarding career, life and performance issues for nearly 20 years. She is the former Manager of the San Mateo County Hospital Consortium's Career Fitness Center, where she provided training and coaching as part of a comprehensive retention strategy. Prior to that, she was the Director of Corporate and Career Education at Maryville University in St. Louis, Missouri.
In addition, Celeste is certified in all of the FIRO instruments, The Human Element®, Radical Collaboration® and The Implicit Career, along with the MBTI®, the Step II®, the ARSENAL, and the BarOn® EQ-i. She holds a Masters degree in Public Administration and was a recipient of the Presidential Management Internship Award. Her Baccalaureate degree is in Communications.
Celeste is an international consultant and co-founder of the Green Zone Culture Group, dedicated to creating organizational cultures where high trust, emotional commitment and collaboration thrive. For over 20 years, Celeste's focus has been on the human side of business, helping leaders and managers create better working environments, Green Zones. Green Zone work environments are characterized by open and effective communication, accountability and cooperation. It is in these environments that human energy soars, employees care about their work and each other, people connect with one another and cooperate to achieve extraordinary results.
Celeste is dedicated to reducing fear and defensiveness in the workplace, the underlying cause of most of the human problems in organizations. She helps leaders and managers achieve this by combining the best of behavioral science and experiential learning to help people develop the skills, the attitude and mindset for building strong relationships. She has a special interest in the emerging fields of neuroleadership and neurobiology. Collaboration with neuroscience researchers has led to training experiences that are brain-friendly, thereby accelerating personal growth and organizational effectiveness.
Celeste has worked with a wide range of clients including NASA, The Human Element Sweden, Chevron, Idaho Power, Business Consultants of Japan, The United Nations, the National Institutes of Health and the National Cancer Institute. A certified Marshall Goldsmith coach, Celeste has been coaching clients regarding career, life and performance issues for nearly 20 years. She is the former Manager of the San Mateo County Hospital Consortium's Career Fitness Center, where she provided training and coaching as part of a comprehensive retention strategy. Prior to that, she was the Director of Corporate and Career Education at Maryville University in St. Louis, Missouri.
In addition, Celeste is certified in all of the FIRO instruments, The Human Element®, Radical Collaboration® and The Implicit Career, along with the MBTI®, the Step II®, the ARSENAL, and the BarOn® EQ-i. She holds a Masters degree in Public Administration and was a recipient of the Presidential Management Internship Award. Her Baccalaureate degree is in Communications.
Linneke Stoltenborgh, Chief Action Officer - A Catalyst for Growth and Connection
Linneke Stoltenborgh is known for her sharp, effective, and hands-on approach to achieving results. She moves with energy and purpose, seamlessly connecting people across all levels of an organization. With her direct and entrepreneurial mindset, she ensures that bold ideas don’t just stay ideas—they turn into action.
Collaboration with Linneke feels natural and effortless. She quickly establishes deep connections within teams, building trust and momentum. Her carefully curated network reflects her strength: a blend of sharp insight, authentic relationships, and a drive to make things happen.
At the core of her work lies openness and honesty—values she embodies and expects from those she works with. Her ability to sense underlying dynamics within organizations, teams, and individuals makes her a powerful guide in navigating change and growth.
With experience as a Talent Development Manager, Recruitment Manager, and HR Business Partner in complex, international environments, Linneke brings both strategic expertise and a deep understanding of human dynamics. Her background in Transformational Presence, Insights Discovery, coaching, group dynamics, and systemic work enriches her ability to unlock new perspectives and drive progress.
But what truly sets Linneke apart is her heart. She brings warmth, humor, and a spirit of playfulness into her work, making growth not just meaningful but also enjoyable. She is someone who listens deeply, challenges with kindness, and inspires action—always with an eye on what truly matters.
Smart, spirited, and deeply committed to growth and connection, Linneke is not just a professional—she’s a force for transformation. With her, you’re always moving forward, always learning, always growing… and always having a lot of fun along the way.
Linneke Stoltenborgh is known for her sharp, effective, and hands-on approach to achieving results. She moves with energy and purpose, seamlessly connecting people across all levels of an organization. With her direct and entrepreneurial mindset, she ensures that bold ideas don’t just stay ideas—they turn into action.
Collaboration with Linneke feels natural and effortless. She quickly establishes deep connections within teams, building trust and momentum. Her carefully curated network reflects her strength: a blend of sharp insight, authentic relationships, and a drive to make things happen.
At the core of her work lies openness and honesty—values she embodies and expects from those she works with. Her ability to sense underlying dynamics within organizations, teams, and individuals makes her a powerful guide in navigating change and growth.
With experience as a Talent Development Manager, Recruitment Manager, and HR Business Partner in complex, international environments, Linneke brings both strategic expertise and a deep understanding of human dynamics. Her background in Transformational Presence, Insights Discovery, coaching, group dynamics, and systemic work enriches her ability to unlock new perspectives and drive progress.
But what truly sets Linneke apart is her heart. She brings warmth, humor, and a spirit of playfulness into her work, making growth not just meaningful but also enjoyable. She is someone who listens deeply, challenges with kindness, and inspires action—always with an eye on what truly matters.
Smart, spirited, and deeply committed to growth and connection, Linneke is not just a professional—she’s a force for transformation. With her, you’re always moving forward, always learning, always growing… and always having a lot of fun along the way.
Gea Wortelboer, Chief Figure-It-Out Officer
Gea is an experienced leadership trainer, coach, and consultant, working with national and international organizations to create high-trust, high-engagement work environments.
With a strong background in leadership, communication, and behavioral change, she helps professionals and teams develop the skills, mindset, and habits needed for effective collaboration, accountability, and resilience. With years of leadership experience herself, Gea understands the challenges leaders face and supports them in creating workplaces where people feel valued, empowered, and connected. She integrates insights from Whole Brain Thinking, Radical Collaboration, Positive Intelligence, and Solution-Focused Coaching to design engaging, brain-friendly learning experiences that drive real transformation.
Beyond leadership and teamwork, Gea is also a certified yoga and mindfulness teacher. She incorporates these practices into her work to help individuals develop greater self-awareness, focus, and emotional balance—key ingredients for sustainable success in both personal and professional life.
Based in Spain, Gea works throughout Europe, guiding leaders and teams to embrace change, navigate complexity, and achieve extraordinary results—together.
Gea is an experienced leadership trainer, coach, and consultant, working with national and international organizations to create high-trust, high-engagement work environments.
With a strong background in leadership, communication, and behavioral change, she helps professionals and teams develop the skills, mindset, and habits needed for effective collaboration, accountability, and resilience. With years of leadership experience herself, Gea understands the challenges leaders face and supports them in creating workplaces where people feel valued, empowered, and connected. She integrates insights from Whole Brain Thinking, Radical Collaboration, Positive Intelligence, and Solution-Focused Coaching to design engaging, brain-friendly learning experiences that drive real transformation.
Beyond leadership and teamwork, Gea is also a certified yoga and mindfulness teacher. She incorporates these practices into her work to help individuals develop greater self-awareness, focus, and emotional balance—key ingredients for sustainable success in both personal and professional life.
Based in Spain, Gea works throughout Europe, guiding leaders and teams to embrace change, navigate complexity, and achieve extraordinary results—together.
Ron Luyet, Advisor and Co-Founder of Green Zone Culture Group
Ron Luyet is co-founder of The Green Zone Culture Group whose consulting practice focuses on building collaborative work environments and he is a Senior Global Consultant with Business Consultants Inc. of Japan. He is co-creator of the Radical Collaboration partnership building training program now offered in countries around the globe. He is co-author of two books: Radical Collaboration: Five Essential Skills to Overcome Defensiveness and Build Successful Relationships (with Jim Tamm) which has been on Amazon’s top seller lists for workplace, negotiations and organizational psychology books for most of the past nine years, and Where Freedom Begins: The Process of Personal Change with Marion Pastor. For more than 30 years he has consulted with many premier companies and organizations seeking to understand the social intelligence dynamics that drive success including: The Boeing Company, Proctor and Gamble, Eli Lilly, Seagram’s Wine & Spirits, Idaho Power as well at NASA, The United Nations, U.S. Department of Defense, The National Cancer Institute and the U.S. Army. Internationally, Ron regularly presented programs for The Human Element Sweden as well as training programs in Denmark, England, Canada, Seoul and Singapore. Twice each year in Japan, Ron presented an 8 day Ningen-Ryoku “Human Power” Leadership Program for Japanese Senior Executives focused on building social capital through increasing social Intelligence skills. He is a master group facilitator and coach whose classic instruction came from such group dynamics pioneers as Dr. Carl Rogers and Dr. Will Schutz. Ron worked closely with Dr. Schutz for more than 30 years, and helped in the design of The Human Element program an integrated approach for building trust and collaboration in the workplace. Ron co-founded The Institute for Personal Change in San Francisco, which provides a structured, intensive therapeutic program for personal growth exploring effects of childhood experiences on adult effectiveness. |
Jim Tamm, Advisor and Co-Founder of Green Zone Culture Group
Jim Tamm is a former judge and an expert in building collaborative workplace environments, with 40 years of experience in the field of alliance building and conflict resolution. As a Senior Administrative Law Judge for the State of California for 25 years, Jim mediated more than 1,000 employment disputes.
His legal decisions have impacted national labor policy in the US, and he has authored training materials that have been published in fourteen languages. The California Senate, the California Assembly and the California Public Employment Relations Board have all honored Jim for his work building more collaborative employment environments.
His most recent book, Radical Collaboration (co-authored with Ron Luyet) was on Amazon’s top seller lists for workplace, organizational psychology, collaboration and negotiations books for most of the past nine years. He is a former law professor and is currently on the faculty of the International Management Program of the Stockholm School of Economics, the Management Education Program at NASA, and the Leadership Academy of the University of California, Santa Cruz, and the Wallenberg Institute in Sweden.
Jim has a diverse client base of international organizations ranging from the United Nations, NASA, Toyota and Boeing, the US Army and Navy, to universities, financial institutions, pharmaceuticals and toy companies.
Jim Tamm is a former judge and an expert in building collaborative workplace environments, with 40 years of experience in the field of alliance building and conflict resolution. As a Senior Administrative Law Judge for the State of California for 25 years, Jim mediated more than 1,000 employment disputes.
His legal decisions have impacted national labor policy in the US, and he has authored training materials that have been published in fourteen languages. The California Senate, the California Assembly and the California Public Employment Relations Board have all honored Jim for his work building more collaborative employment environments.
His most recent book, Radical Collaboration (co-authored with Ron Luyet) was on Amazon’s top seller lists for workplace, organizational psychology, collaboration and negotiations books for most of the past nine years. He is a former law professor and is currently on the faculty of the International Management Program of the Stockholm School of Economics, the Management Education Program at NASA, and the Leadership Academy of the University of California, Santa Cruz, and the Wallenberg Institute in Sweden.
Jim has a diverse client base of international organizations ranging from the United Nations, NASA, Toyota and Boeing, the US Army and Navy, to universities, financial institutions, pharmaceuticals and toy companies.