Dr Nick Brooks, University of East Anglia
Part of the show Peruvian Mummies, Ancient Environments and the Sahara
Kat - I understand that you work in the desert. What can you tell us about that?
Nick - Whenever I get the opportunity I pursue my own field research which is at the moment focussed on the western Sahara. Prior to that I've done quite a lot of work in Libya as part of a much wider project called the Fezzan project, examining the interaction between past climate and environmental change and ancient civilisations.
Kat - So when we think about the desert, you think of something that must have been desert for absolutely thousands of years. But this isn't always the case with the Sahara, is it?
Nick - That's true. The Sahara has been through a number of humid and arid phases that pretty much fall in step with the glacial cycles. The last humid phase in the Sahara lasted from about ten thousand to five thousand years ago. During this period the desert that we know today was more like a savannah environment with open woodland, lakes and rivers.
Kat - So what sort of different cultures and animals and things would we have found there compared to what we have now?
Nick - Well we actually have some very good records that the prehistoric inhabitants of the Sahara very kindly left us if we want to see what they were up to and what the environment was like. Archaeological studies tell us that the region was re-inhabited as it became more humid about ten thousand years ago by hunter-gatherer groups. But later we find the emergence of cattle herding societies and then later still we find sedentary societies such as the Garamantian civilisation in south west Libya. The environment, as I mentioned, was like a savannah much like the environments you'd find in southern Africa today. We also have literally millions of rock paintings and engravings that depict the large humid climate African fauna that we find in the more humid regions now.
Kat - So the civilisations that we find there, we've already heard from Lawrence today who's told us about cultures that were killing each other with a fight for resources. They wanted to keep their stuff for themselves. Do you see similar things as the environment is changing in the Sahara?
Nick - The Sahara is not the same as parts of, say, Egypt, for it's large ancient civilisations, it is a very good place to study these sorts of processes. It's essentially a laboratory of adaptations which has had very very extreme changes of environment and climate and people obviously respond to those. We know that the places in the Sahara that are now uninhabitable were densely inhabited, relatively speaking, in the past. There was archaeological material literally scattered across the desert surface. So yes, we can actually see how people responded to these changes. One of the things that seems to be happening as the climate becomes more arid is that people are becoming more territorial and it appears that we have an increase in social stratification. This is evident largely through burial monuments.
Kat - So do you think that in the same way as in Peru they might have become more blood thirsty or more competitive?
Nick - Obviously there would have been competition. You're talking about a landscape that has been widely inhabited and then desiccated, leading to the formation of very few environmental refugia where there was still water and pasture available. People would have naturally migrated out of the Sahara and there is evidence that people went south with the retreating monsoon. But we also know that people started to congregate around diminishing lakes and oasis regions, and so obviously the population density in these regions increased and there would have been more competition for resources. Whether this would have expressed itself in a particularly violent way, we don't really know. That's not apparent from the archaeological record. No doubt there would have been some conflict but we also know that people adapted their livelihood strategies of their social systems in order to survive in these smaller regions where different resources and techniques were required.
Kat - So do you think that it may have brought civilisations together to form bigger societies?
Nick - I do think that certainly in the Sahara that this did emerge through a process of adaptation to an increasingly arid environment. What you really have is the development of an irrigation-based largely urban society emerging in one of these environmental refuges and as far as we can tell, through a pretty clear process of response to environmental change. I do think that this is a model that seems to hold in other places. For example, it's not that controversial these days to say that the rise of Egyptian civilisation was largely due to the desiccation of the surrounding desert and the social changes that that engendered. So as for being more blood thirsty, we don't know. But we certainly saw the emergence of urban societies with organised armies and organised warfare as the societies developed.
Kat - So we've seen the Sahara getting much drier and as I talked about briefly with Harriet, our climate does appear to be changing. How do you think that societies are going to adapt to the changes that we're going to have in the future?
Nick - Well that's very difficult. Recently when I was away I was actually at the United Nations trying to do some work on adaptation. Obviously there's a big problem with how humans are going to adapt to future climate change. We have a lot of difficulty with this; it's not a trivial problem. We can certainly say that societies will change as a response to climate change, but it's interesting that when we look back in the past, most adaptations to climate change seem to involve things like population movement and migration. Now these are options that aren't really viable today so we're going to have to look for other means. I think that if we have very large changes in climate, as I think are probably going to occur by the end of this century, then there will be a problem.