05/10/2013 15:38 BST | Updated 05/12/2013 05:12 GMT

Gambling on Our Future: Overpopulation and Overconsumption

Last month, Matt Ridley writing in The Times said:

there is almost a perfect correlation between the severity of conservation problems and poverty, because the richer people get, the less they try to live off the land and compete with nature -- the less they seek bushmeat and charcoal from the forest.

There are so many things wrong with this statement that it's hard to know where to start. I'm presuming that Ridley hasn't noticed any of the environmental crises that have reared their heads over the last century or so, including but not limited to anthropogenic climate change, overfishing, and the trade in endangered animal parts. Many of these may be fuelled by poverty but ultimately they are driven by wealth. Elephants and rhinos wouldn't be massacred with such wild abandon if there weren't countless consumers in Asia with the money to pay for their ivory and keratin. Overfishing isn't helped by destructive subsistence practices but the brunt of the blame belongs to the over-efficiency of industrialised fleets. We remain chained to fossil fuels in our insatiable appetite for their energy.

Ridley's article (and his book of the same vein) is indicative of a growing trend of optimism, with various academics and commentators pronouncing that development will solve both poverty and overpopulation. What 'development' do they mean exactly? Western-style development? If that's the case, then we can look forward to a future where we'll need somewhere between 2.5 to 4.1 planet Earths to sustain the requisite lifestyle for every human being alive, as this infographic shows (and even if we all lived like Costa Ricans we'd still need more than the one planet we have). In the face of exponentially increasing consumption the alternative of sustainable development, the blueprint for which was launched by the UN at Rio in 1992, seems barely realised yet.

Some argue that we're already at the point of or nearing "peak consumption," as Danny Dorling does in his book Population 10 Billion published earlier this year. Dorling points to achievements such as the UK population reducing its water usage by 5% between 2003 and 2010 (p.145). No matter that net demand for water is increasing globally and that climate change might dramatically affect its availability. And if it's increasing affluence that eventually brings about peak consumption, that means we'll have to wait for the developing world to catch up before we can be assured that the whole world has reached its peak. That's not to say the development trajectories of third world countries will mirror those of our own, but it seems unlikely that they will veer away much from the standard pattern of intensive resource use, even in light of all the knowledge we have about the planet's life systems now. Only in August the Ecuadorian president announced that oil-drilling would be going ahead in Yasuni National Park, a vital piece of the Amazon rainforest and one of the frontiers in the battle against climate change.

This is the downfall of arguments in favour of our version of development: the planet cannot sustain a predicted number of 10 billion people if they all want to live as we in the developed world currently do. I don't seek to argue that development shouldn't happen, that poor people should stay poor. A cycle of human misery will not solve our various environmental crises. Instead what must be found - and probably won't be, given our reluctance to sacrifice gains in luxury like air conditioning, throw-away fashion and meat every day - is a sustainable middle ground, where those in poverty are elevated by ecologically-informed development to increase their consumption somewhat, and the wealthier decrease their consumption significantly. It's true that new technologies can create new efficiencies, but unless we take ground-breaking new steps like planetary geo-engineering or powering all our vehicles with hydrogen, this will only ever be window-dressing. It's not only our methods that must change; it's ourselves.

Overconsumption and overpopulation are intertwined. The prospect of 10 billion people or more living as we in the developed nations do now is frightening but unrealistic, I think; environmental degradation will crush that aspiration before it can reach full term. Neither we nor the planet will win in that case. However, lifting the masses out of poverty while continuing to champion contraception and empowerment for women are goals we should strive for. Aside from our moral duty towards the rest of humanity, population density can damage the environment in the absence of resource demand from consumers. For example mangrove forests, vital ecosystems for both nature and people, are now facing destruction across the world. Some of their loss is attributable to consumer-driven activities like clearance for prawn-farming. But often local, poor populations depend on the mangroves for staples such as wood fuel and building material. A 2009 study in Cameroon found that even villagers dependent on the mangroves had noticed a link between population growth and the decline of environmental resources in their region. Thus if consumers were to cease buying commodities such as prawns, this would not address the ongoing loss of mangroves.

Solving either overconsumption or overpopulation exclusively is not the answer. Yet the argument of many optimists seems to be: "development will sort out poverty and overpopulation. And then something will hopefully sort out overconsumption".

That's one hell of a gamble.