IN THIS ISSUE
Thematic Focus: Environmental governance, Resource efficiency
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Figure 6: The Pearl River Delta in 1979 had roughly 14 million people; by 2009 population had tripled to 44 million.
It is projected that by 2020, over 70 per cent of China's people will live in its cities (UN 2009). China's rate of rural-to-urban transformation has been largely driven by market reforms put in place in the 1970s and the consequent development of industrial centers such as those in the Pearl River Delta in southeastern China. The area has been an important and productive agricultural area for China but it is losing farmland to some of the fastest urban growth in the world (Seto and Kaufmann 2003). Several urban centers in the greater delta area have experienced dramatic accelerated growth through the 1990s (Sun and others 2010, SEDAC 2010) putting intense pressure on the delta environment (Fragkias and Seto 2009) as the metro areas of Guangzhou, Dongguan, Foshan and Shenzhen have all grown into cities of over five million people each (SEDAC 2010). Population within the area in the images above tripled in just 20 years, from 14 million in 1990 to 44 million in 2010 (SEDAC 2010). As a result, large areas of productive farmland have been lost and fragmented displacing food production to areas with poorer quality cropland and lower productivity (Yan and others 2009). Urban and related land uses are displacing agricultural systems that have adapted to conditions on the delta and have been used in the area for over 1000 years (Lo 1996, Weng 2007). The rate and scale of change has also created other serious environmental concerns, including deforestation; soil erosion; and water pollution from industrial waste, domestic sewage, agricultural chemicals and petroleum (Weng 2007).
Rwanda and Bangladesh
Figure 7: Rwanda has the densest rural population in continental Africa and the country’s growth rate remains at 2.8 per cent per year. Source: Google Earth ©2011, ©GeoEye 2011. Full Size Image
At the other end of the development spectrum, Bangladesh and Rwanda have two of the highest rural population densities among the world's countries. They also both have a very high percentage of their land area under cultivation, and small average farm sizes; mostly subsistence-oriented agriculture which makes up a very large proportion of their economies. Bangladesh's annual population growth rate was 1.4 per cent as of 2009, not far above the global average of 1.2 per cent. Rwanda's annual population growth rate was twice as high, at 2.8 per cent per year (World Bank 2011a). Literacy, which is fairly widely accepted as a driver of lower birth rates, was higher in Rwanda at 65 per cent while it was only 54 per cent in Bangladesh. However, the most recent surveys show that in Bangladesh, 55.8 per cent of couples use family planning methods compared to only 36.4 per cent in Rwanda (UNPD 2011a). Rwanda's rate of family planning use, however, was double what it was just a few years earlier (UNPD 2011a).
Figure 8: Population in rural Bangladesh is very high but the country’s growth rate has slowed to 1.4 per cent per year. Source: Google Earth ©2011, ©GeoEye 2011 Full Size Image
Summary of findings and implications:
World population will exceed seven billion by late 2011 or early 2012. While the rate of growth has slowed in percentage terms, widely accepted projections of future population numbers predict the addition of 2 billion more people before the middle of this century. These projections are based on the application of demographic-transition models, which foresee lower birthrates for many currently developing countries. The demographic transition model clearly explains some of the most central dynamics of population growth rates in a historical context. However, several researchers have questioned assumptions made in the application of the demographic transition model to population projections. Among the assumptions questioned is the assumed availability of adequate cheap energy for current development trends to continue. Finally, even if the UN and US Census Bureau models, which predict 9.3 billion people by mid century, are accurate, many others believe that population level dramatically overshoots the Earth's capacity to sustainably support us. How the pressures of population growth will unfold in different regions of the globe will likely vary considerably, however; in a world of economic globalization and increasing international interdependence, no country will be isolated from the consequences.
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