Increasing human population density drives environmental degradation in Africa

26 06 2019



Almost a decade ago, I (co-) wrote a paper examining the socio-economic correlates of gross, national-scale indices of environmental performance among the world’s nations. It turned out to be rather popular, and has so far garnered over 180 citations and been cited in three major policy documents.

In addition to the more pedestrian ranking itself, we also tested which of three main socio-economic indicators best explained variation in the environmental rank — a country’s gross ‘wealth’ indicator (gross national income) turned out to explain the most, and there was no evidence to support a non-linear relationship between environmental performance and per capita wealth (the so-called environmental Kuznets curve).

Well, that was then, and this is now. Something that always bothered me about that bit of research was that in some respects, it probably unfairly disadvantaged certain countries that were in more recent phases of the ‘development’ pathway, such that environmental damage long since done in major development pulses many decades or even centuries prior to today (e.g., in much of Europe) probably meant that certain countries got a bit of an unfair advantage. In fact, the more recently developed nations probably copped a lower ranking simply because their damage was fresher

While I defend the overall conclusions of that paper, my intentions have always been since then to improve on the approach. That desire finally got the better of me, and so I (some might say unwisely) decided to focus on a particular region of the planet where some of the biggest biodiversity crunches will happen over the next few decades — Africa.

Africa is an important region to re-examine these national-scale relationships for many reasons. The first is that it’s really the only place left on the planet where there’s a semi-intact megafauna assemblage. Yes, the great Late Pleistocene megafauna extinction event did hit Africa too, but compared to all other continents, it got through that period relatively unscathed. So now we (still) have elephants, rhinos, giraffes, hippos, etc. It’s a pretty bloody special place from that perspective alone.


Elephants in the Kruger National Park, South Africa (photo: CJA Bradshaw)

Then there’s the sheer size of the continent. Unfortunately, most mercator projections of the Earth show a rather quaint continent nuzzled comfortably in the middle of the map, when in reality, it’s a real whopper. If you don’t believe me, go to and drag any country of interest over the African continent (it turns out that its can more or less fit all of China, Australia, USA, and India within its greater borders).

Third, most countries in Africa (barring a few rare exceptions), are still in the so-called ‘development’ phase, although some are much farther along the economic road than others. For this reason, an African nation-to-nation comparison is probably a lot fairer than comparing, say, Bolivia to Germany, or Mongolia to Canada.

Read the rest of this entry »

National commitment to conservation brings biodiversity benefits

16 06 2015

united-nations-dayWhat makes some conservation endeavours successful where so many fail to protect biodiversity? Or, how long is a piece of string?

Yes, it’s a difficult question because it’s not just about the biology – such as resilience and area relationships – in fact, it’s probably more about the socio-economic setting that will ultimately dictate how the biodiversity in any particular area fares in response to disturbance.

In the case of protected areas (that I’ll just refer to as ‘reserves’ for the remainder of this post), there’s been a lot of work done about the things that make them ‘work’ (or not) in terms of biodiversity preservation. Yes, we can measure investment, how much the community supports and is involved with the reserve, how much emphasis is put on enforcement, the types of management done within (and outside) of the reserves, et ceteraet cetera. All of these things can (and have to some extent) been correlated with indices of the fate of the biodiversity within reserves, such as rates and patterns of deforestation, the amount of illegal hunting, and the survival probability of particular taxa.

But the problem with these indices is that there are just indices – they probably do not encapsulate the overall ‘health’ of the biodiversity within a reserve (be that trends in the overall abundance of organisms, the resilience of the community as a whole to future disturbances, or the combined phylogenetic diversity of the ecosystem). This is because there are few long-term monitoring programmes of sufficient taxonomic and temporal breadth to summarise these components of complex ecosystems (i.e., ecology is complex). It’s no real surprise, and even though we should put a lot more emphasis on targeted, efficient, long-term biodiversity monitoring inside and outside of all major biodiversity reserves, the cold, hard truth of it is that we’ll never manage to get the required systems in place. Humanity just doesn’t value it enough. Read the rest of this entry »