'The first man who, having enclosed a piece of ground, bethought himself of saying 'This is mine', and found people simple enough to believe him, was the real founder of civil society. From how many crimes, wars and murders, from how many horrors and misfortunes might not anyone have saved mankind, by pulling up the stakes, or filling up the ditch, and crying to his fellows, 'Beware of listening to this impostor; you are undone if you once forget that the fruits of the earth belong to us all, and the earth itself to nobody'."

Jean Jacques Rousseau would recognise this moment. Now it is not the land his impostors are enclosing, but the rest of the natural world. In many countries, especially the United Kingdom, nature is being valued and commodified so that it can be exchanged for cash.

The effort began in earnest under the last government. At a cost of £100,000, it commissioned a research company to produce a total annual price for England's ecosystems. After taking the money, the company reported – with a certain understatement – that this exercise was "theoretically challenging to complete, and considered by some not to be a theoretically sound endeavour". Some of the services provided by England's ecosystems, it pointed out, "may in fact be infinite in value".

This rare flash of common sense did nothing to discourage the current government from seeking first to put a price on nature, then to create a market in its disposal. The UK now has a natural capital committee, an Ecosystem Markets Task Force and an inspiring new lexicon. We don't call it nature any more: now the proper term is "natural capital". Natural processes have become "ecosystem services", as they exist only to serve us. Hills, forests and river catchments are now "green infrastructure", while biodiversity and habitats are "asset classes" within an "ecosystem market". All of them will be assigned a price, all of them will become exchangeable.

The argument in favour of this approach is coherent and plausible. Business currently treats the natural world as if it is worth nothing. Pricing nature and incorporating that price into the cost of goods and services creates an economic incentive for its protection. It certainly appeals to both business and the self-hating state. The Ecosystem Markets Task Force speaks of "substantial potential growth in nature-related markets – in the order of billions of pounds globally".

Commodification, economic growth, financial abstractions, corporate power: aren't these the processes driving the world's environmental crisis? Now we are told that to save the biosphere we need more of them.

Payments for ecosystem services look to me like the prelude to the greatest privatisation since Rousseau's encloser first made an exclusive claim to the land. The government has already begun describing land owners as the "providers" of ecosystem services, as if they had created the rain and the hills and the rivers and the wildlife that inhabits them. They are to be paid for these services, either by the government or by "users". It sounds like the plan for the NHS.

Land ownership since the time of the first impostor has involved the gradual accumulation of exclusive rights, which were seized from commoners. Payments for ecosystem services extend this encroachment by appointing the landlord as the owner and instigator of the wildlife, the water flow, the carbon cycle, the natural processes that were previously deemed to belong to everyone and no one.

But it doesn't end there. Once a resource has been commodified, speculators and traders step in. The Ecosystem Markets Task Force now talks of "harnessing City financial expertise to assess the ways that these blended revenue streams and securitisations enhance the ROI [return on investment] of an environmental bond". This gives you an idea of how far this process has gone – and of the gobbledegook it has begun to generate.

Already the government is developing the market for trading wildlife, by experimenting with what it calls biodiversity offsets. If a quarry company wants to destroy a rare meadow, for example, it can buy absolution by paying someone to create another somewhere else. The government warns that these offsets should be used only to compensate for "genuinely unavoidable damage" and "must not become a licence to destroy". But once the principle is established and the market is functioning, for how long do you reckon that line will hold? Nature, under this system, will become as fungible as everything else.

Like other aspects of neoliberalism, the commodification of nature forestalls democratic choice. No longer will we be able to argue that an ecosystem or a landscape should be protected because it affords us wonder and delight; we'll be told that its intrinsic value has already been calculated and, doubtless, that it turns out to be worth less than the other uses to which the land could be put. The market has spoken: end of debate.

All those messy, subjective matters, the motivating forces of democracy, will be resolved in a column of figures. Governments won't need to regulate; the market will make the decisions that politicians have ducked. But trade is a fickle master, and unresponsive to anyone except those with the money. The costing and sale of nature represents another transfer of power to corporations and the very rich.

It diminishes us, it diminishes nature. By turning the natural world into a subsidiary of the corporate economy, it reasserts the biblical doctrine of dominion. It slices the biosphere into component commodities: already the government's task force is talking of "unbundling" ecosystem services, a term borrowed from previous privatisations. This might make financial sense; it makes no ecological sense. The more we learn about the natural world, the more we discover that its functions cannot be safely disaggregated.

Rarely will the money to be made by protecting nature match the money to be made by destroying it. Nature offers low rates of return by comparison to other investments. If we allow the discussion to shift from values to value – from love to greed – we cede the natural world to the forces wrecking it. Pull up the stakes, fill in the ditch, we're being conned again.

Twitter: @GeorgeMonbiot