WASHINGTON The consumption of forests,
energy, and land by humans is exceeding the rate at which
Earth can replenish itself, according to research published
Monday in the Proceedings of the National Academy of Sciences.
The study, conducted by California-based Redefining
Progress, a nonprofit group concerned with environmental
conservation and its economics, warned that a failure
to rein in humanity's overuse of natural resources could
send the planet into "ecological bankruptcy."
Earth's resources "are like a pile of money anyone
can grab while they all close their eyes, but then it's
gone," said Mathis Wackernagel, lead author of the study
and a program director at Redefining Progress.
Scientists said humanity's demand for resources had
soared during the past 40 years to a level where it
would take the planet 1.2 years to regenerate what people
remove each year. The impact by humans on the environment
had inched higher since 1961 when public demand was
70 percent of the planet's regenerative capacity, the
study showed. "If we don't live within the budget of
nature, sustainability becomes futile," Wackernagel
The study, which details the population's impact on
the Earth with a quantitative number, measured the "ecological
footprint" of human activities such as marine fishing,
harvesting timber, building infrastructure, and burning
fossil fuel that emits carbon dioxide (CO2) into the
atmosphere. Researchers then used government data and
various estimates to determine how much land would be
required to meet human demand for those actions.
For example, Wackernagel and his team found that in
1999, each person consumed an average of 5.7 acres.
The global average was significantly lower than industrialized
countries such as the United States and the United Kingdom,
where 24 acres and 13.3 acres, respectively, were consumed
In order to develop a formula that measured humanity's
consumption with the Earth's regenerative capacity,
the researchers were forced to reach several assumptions
and omit the use of some resources because of insufficient
data. The results, for example, excluded the impact
of local freshwater use and the release of solid, liquid,
or gaseous pollutants other than CO2 into the environment.
Even though the findings revealed that human use of
resources was far outstripping Earth's supply, it stopped
short of determining how long the process could continue
without detrimental consequences.
"Like any responsible business that keeps track of
spending and income to protect financial assets, we
need ecological accounts to protect our natural assets,"
Wackernagel said. "And if we don't ... we will prepare
for ecological bankruptcy."
Wackernagel said the study's results could be used
to gauge the impact of new technologies and how they
affect the environment. The use of an alternative technology,
such as one that produces renewable energy or replaces
natural biological processes, could allow society to
live better without increasing consumption, he said.
Governments could also determine the impact consumers
and businesses were having on depleting area resources
and evaluate potential ways to reduce consumption, Wackernagel