Heinberg, after two years in college and a period of personal study, became personal assistant to Immanuel Velikovsky in November 1979 and after Velikovsky's death assisted Mrs. Velikovsky editing manuscripts. He published his first book in 1985, Memories and Visions of Paradise: Exploring the Universal Myth of a Lost Golden Age, which was the result of ten years of study of myths of paradise. An expanded second edition was published in 1989. This book grew out of his May 31, 1980, address at the Kronos Princeton Seminar, "Velikovsky: The Decade Ahead" which was titled "The Garden, the Fall, and the Restoration". He began publishing his alternative newsletter, the Museletter, in 1992. His next book was published in 1993: Celebrate the Solstice: Honoring the Earth's Seasonal Rhythms through Festival and Ceremony.

In November 1994, he presented "Catastrophe, Collective Trauma and the Origins of Civilization" at the conference "Velikovsky, Ancient Myth and Modern Science", sponsored by Kronia Communications in cooperation with Aeon: A Symposium on Myth and Science in Portland, Oregon.

In June 1995, speaking to the International Society for the Comparative Study of Civilizations in Dayton, Ohio, Heinberg provided "A Primitivist Critique of Civilization" and discussed the ways in which "We are, it would seem, killing the planet."

In January 1997, at the conference "Planetary Violence in Human History" in Portland, Oregon, sponsored by Kronia Communications, he presented "Environmental Catastrophes and the Changing Attitudes Towards Women, Children, Animals, and Nature".

His books from the later 1990s address the relationships between man and the natural world. In 1998 he began teaching at New College of California. Also in 1998, he served on the Advisory Board of Directors for The Mind Exploration Corporation under the leadership of David Talbott.

In 2004, Heinberg provided the closing address for the First US Conference on Peak Oil and Community Solutions. His title was "Beyond the Peak".

In February 2007 Heinberg addressed the Trade Committee of the European Parliament and served as an advisor to the National Petroleum Council in its report to the U.S. Secretary of Energy on Peak Oil. In October 2007 he addressed members of the New Zealand Parliament. Currently he is a Mayor’s appointed member of the Oil Independent Oakland 2020 Task Force (Oakland, California), which has been convened to chart a path for the city to dramatically reduce its petroleum dependence.

Heinberg is now the Senior Fellow of the Post Carbon Institute in Sebastopol, California. He lives in Santa Rosa, California and was a core faculty member of New College of California until the college closed in March, 2008. He taught a course on Culture, Ecology and Sustainable Community. He is also a violinist, illustrator and book designer. He is married to Janet Barocco.

Heinberg was featured in the 2007 documentary Life at the End of Empire.

Heinberg has proposed an international protocol to peak oil management with the aim of reducing the impact of the arrival of the peak. The adoption of the Protocol would mean that oil-importing nations should deal to reduce their importations in an annual percentage, while exporting countries should deal to reduce their exportations in the same percentage. The Uppsala Protocol has been focused in a similar direction.

Heinberg is the editor of Museletter, which has been included in Utne Magazine’s annual list of Best Alternative Newsletters. He has appeared in the documentaries The End of Suburbia, The 11th Hour, Crude Impact, Oil, Smoke & Mirrors, Chasing God, Life at the End of Empire, The Great Squeeze, How Cuba Survived Peak Oil, A Farm for the Future and Ripe For Change.

Heinberg signed a statement released by the organization 9/11 Truth in 2004 that calls for a new investigation into the September 11 attacks. He confirmed his support for the statement in 2009.