Effects of Global Household Proliferation on Ecosystem Services - Landscape Ecology for Sustainable Environment and Culture - page 100

and growth rates were largely overlooked even though households are basic
socioeconomic units and are key components of coupled human and natural
systems.
Households are major consumers of ecosystem services and play important
roles in ecological change. For example, a basic need for each household is a
housing unit (e.g., house, apartment), which drives land-use and land-cover
changes and subsequently changes in ecosystem services. The household sector is
the major consumer of energy in China (Lu et al. 2007 ). Direct and indirect energy
consumption by U.S. households makes up 85 % of national energy use (Bin and
Dowlatabadi 2005 ) and U.S. households emit about 38 % of national carbon
emissions through their direct actions (Dietz et al. 2009 ). On the other hand,
households in many areas are vulnerable to threats induced by land change and
other types of environmental change (McGranahan et al. 2007 ). To restore and
protect ecosystem services, many countries have implemented payments for
ecosystem services (Daily and Matson 2008 ; Liu et al. 2008 ). Many of these
programs, such as the Grain-to-Green Program of China (Liu et al. 2008 ) and the
Silvopastoral Project in Colombia, Costa Rica, and Nicaragua (Pagiola et al.
2007 ), occur at the household level.
Given the importance of households, in this chapter we first illustrate global
household proliferation (growth in household numbers). Then, we discuss effects
of household proliferation on ecosystem services. And finally, we provide sug-
gestions

for ecosystem service research and management in the context of

household proliferation.

6.2 Global Household Proliferation

Among the 172 countries with relevant data (United Nations Centre for Human
Settlements (Habitat) 2001 ; United Nations Human Settlements Programme 2007 ),
136 countries (79 %) had faster increases in household numbers than population
sizes during 1985-2000 (Fig. 6.1 ). Over the period of 2000-2030, an even higher
percentage of countries (91 %) are projected to have faster growth in household
numbers than population sizes (Fig. 6.1 ).
At the global level, household intensity (number of households per 100 persons)
increased 12.6 % from 1985 to 2000. At the country level in 1985, the average
household intensity was 22.9 households per 100 persons, and Jordan had the
lowest intensity (7.9) while Sweden had the highest density (43.9, Fig. 6.2 a). By
2000, the average household intensity increased to 25.8 households per 100 per-
sons. The lowest and highest intensities also increased. Sweden still held the
highest spot (48.1), but the country with the lowest intensity had switched to
Liberia (9.7) (Fig. 6.2 b). The trends of increases in household intensity are pro-
jected to continue into the future (Fig. 6.2 c).
Over time, a country can have fewer people but more households. During 1985-
2000, population declined in 12 countries, but their household numbers increased