Few nations better illustrate the idea of a ‘perfect storm’ (see blog 16-7-14) than Bangladesh. With per capita incomes at only around $1000 per year it’s a poor country. With the 8th largest population in the world - and still rapidly growing - it’s one of the most densely populated. Spread out over the Ganges-Brahmaputra delta, 160 million people have to utilise all the available natural resources in order to sustain life. Not surprisingly the country is vulnerable to ecological degradation caused by unsustainable use of mangrove forest and groundwater. But it’s also affected by changes taking place beyond its borders - and control – such as managed river flows upstream, rising sea levels and the unpredictable nature of destructive cyclones coming out of the Bay of Bengal. There is a real sense that over the next decade or so these different elements could increasingly affect each other in quite unpredictable and devastating ways.
Up until now we didn’t have a clear picture of how these elements had changed over time and with respect to each other. It was tricky to answer some key questions. How quickly is the environment changing? What is the trade off between rising incomes and ecological deterioration? Is shrimp farming or rising sea level the cause of declining water quality? Is there any evidence that the ‘storm’ is already brewing?
Figure 1. Trends for the different trends in A) per capita income and poverty alleviation; b) mangrove density and cultural services; and c) regulating services (water availability, water quality and groundwater), food provisioning services, climate (rainfall and temperature) and wealth (GDP).
Our new study (Hossain et al., 2015) tackles these questions by reconstructing the changes in ecosystem services – the benefits we get from nature - across the coastal zone of Bangladesh since 1950. Comparing the social and biophysical trends over this period reveals (Figure 1) some interesting changes. The good news is that rising levels of food production have led to rising incomes and, over the past 15 years, a drop in the number of people living under the poverty line. The bad news is that these trends are linked to deteriorating water availability, water quality and land stability – at least by comparison with the 1960s. The concern is that eventually these deteriorating trends will undermine people’s ability to conduct viable agriculture. Further, statistical analyses of the data suggest that rapid ecological changes in the 1980s constitute tipping points – that is, the trends are accelerating as a result of strong positive feedback mechanisms. Theory predicts that such changes are difficult to slow down and sometimes impossible to reverse. So, is Bangladesh heading towards a ‘perfect storm’?
Inevitably, we want to see more results from our colleagues’ ongoing research (ESPA Deltas) particularly from the mathematical models that are simulating future changes. But on the present evidence you would have to say yes - it’s highly probable - especially if climate projections for the rate of sea level rise and more frequent cyclones are correct.
Simply put, too many trends are running in the wrong direction - and converging.
Hossain, M.S., Dearing, J.A., Rahman, M.M., and Salehin, M. 2015. Recent changes in ecosystem services and human wellbeing in the Bangladesh coastal zone. Regional Environmental Change. DOI 10.1007/s10113-014-0748-z Open access download here