In 1972's The Limits to Growth, the authors made a case that, if trends in resource use, population, pollution, industrial and agricultural production continued, the world would reach its limits to growth within a century. They also showed that it would be possible to avoid this catastrophe, and that doing so would be easier the earlier the world began.
Here's a paragraph from the 1992 sequel, Beyond the Limits:
But until we started updating The Limits to Growth we had not let our minds fully absorb the message. The human world is beyond its limits. The present way of doing things is unsustainable. The future, to be viable at all, must be one of drawing back, easing down, healing. Poverty cannot be ended by indefinite material growth; it will have to be addressed while the material human economy contracts. Like everyone else, we didn't really want to come to these conclusions.