For decades, public life has treated economic growth as the default measure of progress. A growing economy has been taken to mean a healthier society, a stronger government and a more secure future.
This assumption is now so familiar that it often disappears from view. Governments are judged by growth figures. Political promises are made in the language of productivity, competitiveness and expansion. Even environmental policy is often framed around the question of how we can keep the economy growing while reducing its harms.
But, on a finite planet, that assumption is becoming harder to sustain.
Why it’s time to rethink prosperity
Have we outgrown a growth-obsessed economic system? That’s the question at the heart of the Grantham Centre for Sustainable Future’s new series, Rethinking Prosperity on a Finite Planet. Across public talks, film screenings, book-club-style discussions, and articles, the series brings together leading voices in post-growth scholarship, ecological economics, environmental economics, industrial policy, and global political economy. Its aim is not to promote a single settled answer, but to ask whether existing economic frameworks are sufficient to deliver climate stability, ecological resilience and social justice, and to explore what alternative or complementary ways of thinking about prosperity might now be needed.
When exponential growth meets a finite planet
This is not a new question. In 1972, The Limits to Growth famously asked what happens when exponential economic and population growth meet a finite planet. Its scenarios were often caricatured as simple predictions of collapse, but the more important point was subtler: ecological limits are not external to the economy. They are part of the system within which economic life takes place.
More than fifty years later, that question has returned with renewed force. Climate breakdown, biodiversity loss, material extraction and global inequality all raise difficult questions about whether prosperity can continue to be defined through expansion. Yet there is still no single agreed answer to what should come next.
Exploring the post-growth concern
Much of this series starts from a post-growth concern: the possibility that high-income economies are now locked into patterns of expansion that are increasingly difficult to reconcile with climate stability, ecological limits and global justice.
That concern runs through Simon Mair’s work on labour and post-capitalist futures, Milena Büchs’s work on sustainable welfare and growth dependence, and, in a different way, Julia Martin-Ortega’s work on how we value nature and make environmental decisions. But the series is not simply about asserting a post-growth answer in advance. Phoebe Koundouri’s contribution brings in a different emphasis, rooted more strongly in environmental economics, policy reform, innovation and the possibility of green growth.
That tension matters. The question is not whether we can attach the right label to the future - green growth, post-growth, degrowth, sustainable development - but whether our accounts of prosperity are credible under conditions of ecological constraint.
Is green growth really possible?
If green growth is possible, then it needs to be demonstrated not only in theory, but in terms of the speed, scale and fairness of real-world decoupling. If it is not, then post-growth arguments need to move from critique to institutional design: work, welfare, care, industry, finance and everyday life.
Either way, the old assumption that prosperity can be equated with ever-rising GDP is no longer enough.
The debate about green growth is often reduced to whether GDP can be decoupled from emissions or resource use. But the harder question is whether this can happen fast enough, globally enough and fairly enough. Relative decoupling matters, but it is not the same as reducing total pressure on ecological systems at the speed demanded by climate science and justice.
A growing body of literature has sharpened this challenge, questioning whether green growth is plausible at the required speed and scale, and arguing that well-being must be decoupled from material throughput, not just GDP from emissions.
These arguments do not settle the debate, but they raise the bar for it.
Preparing for economic slowdown
There is also a pragmatic reason to take these questions seriously.
Recent work in Nature Human Behaviour argues that developed democracies should prepare for long-run economic slowdowns, driven by ageing populations, the shift from goods to services, debt, and climate change. Post-growth may, therefore, be not only an environmental argument, but also a condition for which high-income societies need to prepare.
That makes the question of prosperity more urgent. If welfare systems, public finances, employment expectations and democratic legitimacy all assume a return to strong growth, what happens if that growth does not arrive? And if pursuing growth at all costs is neither safe nor just, what kinds of institutions would allow people to live well anyway?
This is why the debate cannot be left to economics alone. Prosperity may be measured through economic indicators, but it is ultimately about how we organise collective life: what we value, what we produce, how we distribute security and opportunity, and what obligations we recognise to each other and to the living world.
Rethinking prosperity is therefore also about institutions, culture, democracy and imagination; about how we live, and how we decide how to live.
That is why the Grantham Centre for Sustainable Futures is well placed to host this conversation. Sustainability cannot be reduced to a technical problem. Technologies, data, assessment tools and scientific expertise are essential, but they are not enough on their own. The transition also requires political economy, public reasoning, institutional change and a willingness to question some of the assumptions that have shaped economic life for decades.
A finite planet does not mean a poorer idea of prosperity. It should push us towards a richer one.
Prosperity should mean secure livelihoods, good work, time, care, health, ecological stability, democratic participation and the ability of future generations to inherit a liveable world. It should mean asking not only how much an economy produces, but what it produces, for whom, under what conditions and at what cost.
The task, then, is not simply to make the existing economy a little less damaging. It is to ask what prosperity could mean once we take ecological limits seriously and what kinds of institutions, policies and practices might allow that prosperity to be shared fairly.
Whether you are a researcher, student, policymaker, practitioner, activist, or simply someone trying to make sense of what a liveable future might require, we hope you will join us for Rethinking Prosperity on a Finite Planet.