---
title: "John D. Hamaker"
chunk: 1/5
source: "https://en.wikipedia.org/wiki/John_D._Hamaker"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:06:25.991451+00:00"
instance: "kb-cron"
---

John D. Hamaker (1914–1994), was an American mechanical engineer, ecologist, agronomist and science writer in the fields of soil regeneration, rock dusting, mineral cycles, climate cycles and glaciology.

== Biography ==

=== Background ===
Hamaker was born in St. Louis, Missouri, United States, and graduated from Purdue University in Mechanical Engineering. Concerned for the environment, he became a student of ecology and agriculture and was influenced by books such as Bread From Stones, which showed that plants grow better in soils generated by mimicking natural soil-forming processes that take millennia, such as the advance and retreat of glaciers scouring the Earth's crust, or rock weathering of volcanic lava. In the 1960s, Hamaker cultivated an interest in soil and climate issues, and began publishing articles about how the health of an individual, society and planetary ecology thrive only as an interdependent whole. For 30 years, he wrote and campaigned for organic agriculture based on soil remineralization, and was the first to call for the remineralization of the Earth to forestall the next glacial period within the current ice age cycle. He produced a book, The Survival Of Civilization, in 1982, republished in 2002 as Remineralize The Earth.

=== Early developments ===
In the 1970s, a series of scientific conferences concluded that the world's climate was cooling. Books such as The Cooling, The Weather Conspiracy, The Weather Machine & The Threat Of Ice, Climates Of Hunger, Ice Ages and Climate: Present, Past & Future warned of a coming ice age within decades. In 1975, Newsweek ran an article entitled "The Cooling World" that foretold the decimation of agricultural productivity based on a dramatic decrease in the Earth's temperature. and the New York Times published the article "Scientists ask why world is changing; Major cooling may be ahead". In parallel, books such as A Blueprint for Survival, The Limits To Growth, and The Population Bomb, warned of multiple social, economic, ecological and population crises. At the same time, Hamaker continued to generate articles and bulletins and campaign for the remineralization of the world's soils.
According to his writings, in 1976, Hamaker spread rock dust on part of his 10 acres (40,000 m2) in Michigan. The following year, his corn produced 65 bushels per acre, compared to yields of under 25 from other local farms, and also tested higher in many minerals. He calculated that remineralizing the soil with river, seashore, mountain and glacial rock dust would enable American agriculture to produce four times as much food or the same amount with a 25% reduction in cost, without the need for pesticides or chemical fertilizers.

=== The Survival Of Civilization ===
In 1982, he produced with Californian ecologist Donald A. Weaver The Survival Of Civilization: Carbon Dioxide, Investment Money, Population – Three Problems Threatening Our Existence, which was re-published by Remineralize The Earth in 2002 and in 2006 by SoilandHealth.org. Annotations and supporting evidence were provided by Weaver. The book which initially sold 14,000 copies, concerned the threat of an imminent ice age, remineralizing the world's soils on a local and global scale and reforesting the planet to return atmospheric carbon dioxide to a normal interglacial level near 280 ppm, to help slow the glacial advance.
The treatise was a synthesis of Hamaker's thinking that emerged from his studies and research in several disciplines including soil science and paleoclimatology. His message, dubbed the Hamaker Thesis, was that due to modern agricultural and agro-forestry practices, the soils were running out of minerals, causing the dying and burning of forests worldwide and nutrient deficiencies in food. He offered soil remineralization as a solution, advocating regeneration of soil and forests with rock dusts as an economic and ecologically sustainable alternative to chemical fertilizers and pesticides. Hamaker regarded this as one of the most powerful ideas in human history. The book and its message was well received by soil and nutritional scientists and regarded as a blueprint for restoring the planet's ecological integrity by the worldwide remineralization movement.

=== Testimonials ===
Endorsing the book, Buckminster Fuller, inventor of the geodesic dome, author of the book Critical Path and Professor Emeritus at the University of Pennsylvania, wrote in a publicized letter to Donald Weaver in 1983: "I have received and read John Hamaker's The Survival of Civilization. Well done. Completely convincing.... I will tell all those inquiring of me about matters relevant to our survival that they had best read Hamaker's book." Reviewing the book, writer Bertram Cohen expressed concern that a global climate shift would make the temperate zone part of the sub-arctic zone and deprive humanity of its food supply. Cohen also pointed out that "Dr Herbert Shelton, both in his books and in Hygienic Review, emphasised the importance of soil remineralization in creating a Hygienic Agriculture."
In support of the book, The Earth Renewal Society presented a statement to a Congressional hearing in Chicago in March 1984.

== Discoveries and inventions ==

=== Rock medicine ===
Hamaker believed remineralizing the world's soil with rock dust, a quarrying by-product, could revitalise barren soil and reverse climate change. Rock dust nourished soil micro-organisms whose protoplasm is the basis of all living things. When mixed with compost, the dust created rich, deep soils which could produce high growth vegetation free from pests and predators, at an accelerated rate. The idea was later confirmed by agricultural scientists such as Arden Andersen, who showed how high sugar and mineral levels in soil gave immunity to soil bacteria, stopping insect and fungal attacks. For Hamaker and Andersen, minerals were the primal food for micro-organisms which provided life and health for the soil.