“Fairytales of eternal economic growth.” That’s how climate activist Greta Thunberg depicted the dominant mindset at the United Nations last week. “How dare you,” she said, admonishing them for “empty words” instead of concrete actions to preserve the planet.

She’s right. One of the reasons nations fail to address climate change is the belief that we can have infinite economic growth independent of ecosystem sustainability. Extreme weather events, melting arctic ice, and species extinction expose the lie that growth can forever be prioritized over planetary boundaries.

It wasn’t always this way. The fairytale of infinite growth—which so many today accept as unquestioned fact—is relatively recent. Economists have only begun to model never-ending growth over the last 75 years. Before that, they had ignored the topic for a century. And before that, they had believed in limits. If more people saw the idea of infinite growth as a departure from the history of economics rather than a timeless law of nature, perhaps they’d be readier to reimagine the links between the environment and the economy.

In 1950, the economics profession had surprisingly little to say about growth. That year, the American Economic Association (AEA) asked Moses Abramovitz to write a state-of-the-field essay on economic growth. He quickly discovered a problem: There was no field to review.

The founding fathers of economics shared a belief that growth was finite, and that the reason for limits lay in the natural world.

Yes, John Maynard Keynes had offered a theory of stagnation, demonstrating the need for government spending to stimulate an economy mired in recession, and Austrian political economist Joseph Schumpeter had studied creative destruction, highlighting the importance of entrepreneurs and innovation. Wesley Mitchell, founder of the National Bureau of Economic Research, had looked at business cycles and others had analyzed monetary forces. But no one had put it all together in a theory of growth. Modern work was “fragmentary” and had “remained on the periphery of economics,” Abramovitz explained to AEA members. Development economist W. Arthur Lewis agreed, noting in 1955 that “no comprehensive treatment of [economic growth] has been published for about a century.”