JOHANNESBURG May 24 Capital in Africa remains scarce by any traditional measure of the term.
But conservationists say the continent is rich in "natural capital" and argue that if this was properly harnessed, the region would reap dividends and grow its economy and more orthodox forms of capital.
Calculating Africa's natural capital is the focus of a 2-day conference, organised by green group Conservation International (CI), that began on Thursday in Botswana's capital Gaborone.
The traditional measurement of gross domestic product, or GDP - the value of all the goods and services produced by an economy - has long been in the sights of critics who feel it is one-sided or misleading.
Alternatives range from Bhutan's Gross National Happiness index to the U.N.'s annual Human Development Index, which includes life expectancy and education as well as income.
There have been various stabs at "greening GDP" and much of the debate centers on natural capital and how it is valued.
For example, the World Bank last year estimated around one third of the wealth of low-income countries stemmed from their natural capital, which it said included forests, protected habitat, farmland, energy and minerals.
It said diamond-rich Botswana, host of the current conference, had translated its "natural capital" into other wealth by reinvesting the returns in human capital. The result was a 35 percent rise in per capita GDP between 1995 and 2005.
Some environmentalists feel it is useful to put more weight on renewable natural capital such as wildlife, forests or fisheries, instead of commodities such as oil and minerals, which have often proven a curse for African economies.
"It's important to measure the value of renewable natural capital because this data gives a more true picture of the economic benefits of these services to supply chains and people, or alternately, the economic costs if these services are lost and need to somehow be replaced," said Frank Hawkins, Senior Vice President for CI's Africa and Madagascar Division.
"In accounting for and valuing renewable natural capital, we don't include nonrenewable capital such as extracted minerals or oil because we can't replenish these," he said.
According to CI, Botswana's natural capital in 2000 was worth almost $3.2 billion, of which over 50 percent was "non-timber forest resources" which would include wildlife and nature-based tourism.
Botswana is certainly rich in wildlife: it has around 150,000 elephants or one for every 14 people, the highest elephant-to-people ration in Africa.
There would be some problems working out a valuation. For example, while elephants are a major tourist draw, some ecologists say there are too many in Botswana and they are damaging other forest resources by eating themselves out of house and home.
And while diamonds in the ground may not be forever, the value of non-renewable resources still trump the renewable ones for now by most reckonings.
In 2010, Citigroup estimated South Africa was sitting on $2.5 trillion worth of non-energy mineral reserves, the richest in the world. This was mostly because of its vast platinum group metal resources which it valued at $2.2 trillion.
That would clearly dwarf its 20,000 or so elephants.
Still, the greens are on to something here. Resources such as clean, fresh water are becoming more valuable because of scarcity while the importance of forests, and their price tag, is rising because of their role in carbon storage.
The limits of the traditional measure of GDP were recently highlighted by Nigeria's rebasing of its number, a move that will inflate the size of its economy by 40 percent and put it on track to soon overtake South Africa.
Nigeria would not contend with South Africa on many other fronts and while it remains rich in oil reserves it is seen as poor in natural capital.
"The national value of Nigeria's renewable natural capital would be relatively low because they're already spent most of this natural wealth in converting landscapes and ecosystems," said Hawkins.