“How can a future global population of nine billion people all be fed healthily and sustainably?” This is the question a gathering of agricultural projects and experts will seek to address at a workshop in Nairobi next week. Unfortunately, as with almost all things ‘development’, it raises more questions than it could ever hope to answer.

While more than a handful of NGOs are figuring out how we feed so many people, others are trying to figure out how we avoid getting that crowded in the first place. It’s a tricky balance, and on my frequent trips to Africa I’ve found myself wondering how on earth the development sector – which struggles to come to terms with the effects of even today’s population levels – is going to cope when there are another three billion of us charging around. The answer could be, of course, that it won’t.

My year working with primates in Nigeria back in 2002 starkly reminds me of the impact of rapid population growth. Trying to preserve natural resources – rainforests and watershed systems among them – is nigh on impossible when put up against poverty-stricken, ever-expanding human populations. “Islands of biodiversity in a sea of humanity” is exactly where we seem to be headed, and in Nigeria I often found myself wondering if I was wasting my time, if our efforts were simply a stalling tactic and that, ultimately, all the primates and forests would eventually disappear whatever our efforts.

Technology is – of course – often seen as the answer, but in the context of a global population boom recent advances are arguably more the cause. As more of us live (and live for longer), genetically modified crops – however much we love or hate them – are likely the only realistic way enough food can be grown for so many people without turning the planet into one giant corn field. Planet Earth doesn’t have an infinite carrying capacity, and as the likes of James Lovelock are all-too-keen to remind us, we passed that point some time ago.

The primary objective of large numbers of humanitarian organisations is to save lives, to increase life expectancy and to lower child mortality, and until poverty is eradicated around the world population growth will be an unavoidable side effect of their actions. Other than morally being the right thing to do, saving lives just happens to be one of the few developmental activities that can be measured with any degree of accuracy.

But I sometimes wonder if we spend too much time thinking about the numbers. Surely there are times when it’s just as much about quality as it is about quantity. When it comes to human lives, quantitative isn’t necessarily better than qualitative.

This is why I find myself constantly drawn to this old Christian Aid campaign, one which struck me the very first time I saw it. Increasing life expectancy needs to go hand-in-hand with an increased quality of life, and it’s easy to forget this simple message in our relentless drive to “develop”. I sometimes wonder whether, through our own work here, we’re contributing to this in the right – or the wrong – way.