By Richard Black
Environment Correspondent, BBC News website
"If our economies are to flourish, if global poverty is to be banished, and if the well-being of the world's people enhanced - not just in this generation but in succeeding generations - we must make sure we take care of the natural environment and resources on which our economic activity depends."
That statement comes not, as you might imagine, from a stereotypical sandal-wearing, tree-hugging, save-the-world greenie, but from Britain's Chancellor of the Exchequer Gordon Brown, a politician with a reputation for rigour, thoroughness and above all, prudence.
A surprising thing for the man who runs one of the world's most powerful economies to say?
Perhaps; though in the run-up to the five-year review of the Millennium Goals, he is far from alone.
The roots of his speech, given in March at the roundtable meeting of environment and energy ministers from the G20 group of nations, stretch back to 1972, and the United Nations Conference on the Human Environment in Stockholm.
SERVICES FROM THE PLANET
food, fresh water, food, genetic resources
climate, disease, floods, storms
spiritual, recreational, aesthetic, inspirational, educational
soil formation, nutrient cycling, primary production
Source: Human and Environmental Security -
An Agenda for Change ed. Dodds & Pippard
"The protection and improvement of the human environment is a major issue which affects the well-being of peoples and economic development throughout the world," read the final declaration from this seminal gathering, the first of a sequence which would lead to the Rio de Janeiro Earth Summit in 1992 and the World Development Summit in Johannesburg three years ago.
But where is the data?
Hunt through the reams and reams of reports prepared by UN agencies and development groups - many for conferences such as this year's Millennium Goals review - and you will find that the linkage between environmental protection and economic progress is a common thread.
Managing ecosystems sustainably is more profitable than exploiting them, according to the Millennium Ecosystem Assessment.
But finding hard evidence to support the thesis is not so easy.
Thoughts turn first to some sort of global statistic, some indicator which would rate the wealth of nations in both economic and environmental terms and show a relationship between the two.
If such an indicator exists, it is well hidden.
And on reflection, this is not surprising; the single word "environment" has so many dimensions, and there are so many other factors affecting wealth - such as the lottery of oil deposits - that teasing out a simple economy-environment relationship would be well-nigh impossible.
The Millennium Ecosystem Assessment, a vast four-year global study which reported its initial conclusions earlier this year, found reasons to believe that managing ecosystems sustainably - working with nature rather than against it - might be less profitable in the short-term, but certainly brings long-term rewards.
And the World Resources Institute (WRI) in its World Resources 2005 report, issued at the end of August, produced several such examples from Africa and Asia; it also demonstrated that environmental degradation affects the poor more than the rich, as poorer people derive a much higher proportion of their income directly from the natural resources around them.
Trash into cash
But there are also many examples of growing wealth by trashing the environment, in rich and poor parts of the world alike, whether through unregulated mineral extraction, drastic water use for agriculture, slash-and-burn farming, or fossil-fuel-guzzling transport.
Of course, such growth may not persist in the long term - which is what Mr Brown and the Stockholm declaration were both attempting to point out.
Perhaps the best example of boom growth and bust decline is the Grand Banks fishery.
For almost five centuries a copious supply of cod provided abundant raw material for an industry which at its peak employed about 40,000 people, sustaining entire communities in Newfoundland.
Then, abruptly, the cod population collapsed. There were no longer enough fish in the sea for the stock to maintain itself, let alone an industry.
More than a decade later, there is no sign of the ecosystem re-building itself. It has, apparently, been fished out of existence; and the once mighty Newfoundland fleet now scrabbles for crab on the sea floor.
There is a view that modern humans are inexorably sowing the seeds of a global Grand Banks-style disaster.
The idea is that we are taking more out of what you might call the planet's environmental bank balance than it can sustain; we are living beyond our ecological means.
One recent study attempted to calculate the extent of this "ecological overshoot of the human economy", and found that we are using 1.2 Earth's-worth of environmental goods and services - the implication being that at some point the debt will be called in, and all those services - the things which the planet does for us for free - will grind to a halt.
Whether this is right, and if so where and when the ecological axe will fall, is hard to determine with any precision - which is why governments and financial institutions are only beginning to bring such risks into their economic calculations.
It is also the reason why development agencies are not united in their view of environmental issues; while some, like the WRI, maintain that environmental progress needs to go hand-in-hand with economic development, others argue that the priority is to build a thriving economy, and then use the wealth created to tackle environmental degradation.
What price progress?
This view assumes that rich societies will invest in environmental care.
But is this right? Do things get better or worse as we get richer?
Here the Stockholm declaration is equivocal. "In the developing countries," it says, "most of the environmental problems are caused by under-development."
So it is saying that economic development should make for a cleaner world? Not necessarily; "In the industrialised countries, environmental problems are generally related to industrialisation and technological development," it continues.
In other words, poor and rich both despoil the natural world, but for different reasons.
Clearly, richer societies are able to provide environmental improvements which lie well beyond the reach of poorer communities.
Citizens of wealthy nations demand national parks, clean rivers, clean air and poison-free food.
They also, however, use far more natural resources - fuel, water (all those baths and golf courses) and building materials.
A case can be made that rich nations export environmental problems, the most graphic example being climate change.
The figures given here for these four countries will not be completely accurate. Measuring emissions is not a precise science, particularly when it comes to issues surrounding land use; not all nations have released up-to-date data, and in any case, emissions from some sectors such as aviation are not included in national statistics.
As a country's wealth grows, so do its greenhouse gas emissions
But the data is exact enough for a clear trend to be easily discernible.
As countries become richer, they produce more greenhouse gases; and the impact of those gases will fall primarily in poor parts of the world.
Wealth is not, of course, the only factor involved. The average Norwegian is better off than the average US citizen, but contributes about half as much to climate change.
But could Norway keep its standard of living and yet cut its emissions to Moroccan or even Ethiopian levels?
That question, repeated across a dozen environmental issues and across our diverse planet, is what will ultimately determine whether the human race is living beyond its ecological means as it pursues economic Nirvana.