RISING economic prosperity is bad news for biodiversity. Contrary to economic
wisdom, most organisms do not benefit when human income levels go up,
researchers at the University of Alberta, Canada, have found. Birds are the only
animals to do well, they say.
“The often repeated claim that economic development will eventually result in
reduced environmental degradation does not hold when considering numbers of
threatened species,” biologist Robin Naidoo told the SCB’s annual conference
this week.
Previous studies have shown that environmental damage only gets worse to a
certain point. As incomes continue to rise, growing demand for environmental
quality reverses some of the damage. Such a relationship—dubbed an
environmental Kuznets curve—holds true for a number of environmental
problems, including pollution. The new study is the first to look at whether
loss of biodiversity follows this trend.
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Using data on biodiversity and economic activity from 139 countries, Naidoo
and environmental economist Wiktor Adamowicz examined the relationship between
per capita income and the numbers of threatened species in each country,
accounting for differences in area, total species numbers and land use. They
found strong correlations between the numbers of endangered species and economic
activity levels for five out of seven major groups of organisms.
Birds followed the Kuznets pattern, with the greatest number of species
coming under threat at medium levels of economic development. But the number of
species of reptiles, amphibians, invertebrates and plants that faced extinction
climbed steadily with growing economic prosperity. Mammals and fish showed no
significant trends.
The results suggest that, despite conservationists’ efforts to rally support
for the protection of whole ecosystems, existing measures largely benefit only
those species people find appealing. “Because of their colourful appeal, birds
might make out better than most organisms in countries that have the money to
put into conservation,” says ecologist Gretchen Daily of Stanford University,
California.
Other studies have shown that people are willing to pay more to protect birds
than other kinds of organisms. Naidoo notes that in the US, a small number of
bird species, such as the bald eagle, receive a large percentage of the total
funding for endangered species recovery. However, Daily warns: “Prospects aren’t
good for most species. We’ll fail if we restrict our focus to birds.”
Naidoo says that the strongly negative trends in other taxa also highlight
the need for increased public education regarding the value of the “small and
slimy” species that make up the majority of the Earth’s biological
diversity.
