Buy Nothing day is only the beginning for a new counter-consumer culture

Ask a representative group of people what is the greatest threat facing humankind in the 21st century and a number of suggestions will follow. Terrorism, hunger, poverty and pandemics will probably be among them. Few would probably say that the way we consume should be at the top of the list, but there's good reason to believe that this is in fact the correct answer – especially now, one day before the official UK Buy Nothing day.

The reason is simple. For all its sophistications, our modern culture and the mainstream economics that underpin it do not put a price on nature – and nature is set to be the ultimate limiting factor on human progress and welfare as we head toward the middle decades of this century. In some respects, the natural world is already central to our concerns as renewable and non-renewable resources are depleted, ecosystems are degraded and the climate's stability is threatened.

But the scale of our mishandling of the natural world is much bigger than this. One widely cited study, published in 1998 by US economist Robert Costanza and his colleagues, gives an indication of just how big. They set out to estimate the financial cost of replacing all the services provided to us by nature. The pollination of crops, restoration of soil fertility and recycling of wastes; the coastal protection provided by coral reefs and mangroves; the creation of rain by natural forests and the climatic stability that enables human societies to develop – all of these were estimated to be roughly double the value of GDP in that year.

We know now that those free services have been taken far too much for granted. Climate change is a very prominent issue in terms of media coverage and political attention, but it's not the only ecological concern that should on our list. The depletion of so-called ecosystem services – ranging from deforestation to overfishing, soil erosion and fresh water deficiency – are already real economic concerns in many parts of the world.

If we change our approach toward economics, work on the culture of consumerism and change our expectations as to what constitutes a good life, we might still avoid an ecological "crash" later this century.

The economic crisis that we are living through right now might be just the opportunity to make the required transition – to arrive in an economy that meets needs and alleviates poverty while at the same time preserving the natural world so that people in the future might have the means to enjoy good lives. But can we seize the moment – or will the temptation to restore the economy with debt-fuelled consumerism prevail?

Western societies must face up to the issue of how their citizens consume, because a throwaway culture is certainly not compatible with a sustainable one. Our demand for energy and resources now outstrips the planet's ability to meet it and is one of the major drivers of environmental change.

Downshifting to a less resource-hungry economy need not mean the end of comfort and security, or the beginning of mass unemployment. Going green could create millions of jobs, generate new markets, stimulate new technologies and provide opportunities for dynamic new businesses – and in the process conserve the natural systems upon which we all depend. New measures of economic performance are needed, ones that consider human wellbeing as coexistent with the health of the natural world, and account for the state of nature's capital.

While such a transformation, until recently, sounded like a utopian dream, it increasingly looks like our only option to avoid a humanitarian and ecological catastrophe. The moment has arrived to build a culture and economy fit for a finite planet – the only question is how. A good place to start is with ourselves, by working to change our habits and curb our excesses as individual consumers. And what better way to do this than buying nothing for a day?

Originally published by The Guardian.