A Pioneer in Systems Theory and Sustainability for Spaceship Earth

Boulding's work goes all the way back to the 1960's.

 https://www.inspiringquotes.us/author/3917-kenneth-e-boulding

A sample of his thoughts---

“Anyone who believes exponential growth can go on forever in a finite world is either a madman or an economist.”

-- Kenneth E. Boulding

“As long as man was small in numbers and limited in technology, he could realistically regard the earth as an infinite reservoir, an infinite source of inputs and an infinite cesspool for outputs. Today we can no longer make this assumption. Earth has become a space ship, not only in our imagination but also in the hard realities of the social, biological, and physical system in which man is enmeshed.”
-- Kenneth E. Boulding

“Physicists only talk to physicists, economists to economists-worse still, nuclear physicists only talk to nuclear physicists and econometricians to econometricians. One wonders sometimes if science will not grind to a stop in an assemblage of walled-in hermits, each mumbling to himself words in a private language that only he can understand.”
-- Kenneth E. Boulding

“Economics has been incurably growth-oriented and addicted to everybody growing richer, even at the cost of exhaustion of resources and pollution of the environment.”
-- Kenneth E. Boulding

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Not only my opinion.  Be Well