A Handbook for Understanding Natural Capital - Earth Economics

SO WHAT’S
THE PROBLEM
As ecosystems
are lost, so are
the services
those ecosystems
previously provided.
Once, raw materials were plentiful and built capital was
scarce. As a result, we live in a society that has long placed
great value on built capital like roads, dams and machinery,
and less value on the raw materials (natural capital)
required to construct these things. Over the past 50 years,
however, humans have altered ecosystems more rapidly and
extensively than in any comparable period in human history.
Today we have plenty of built capital, while natural capital like
healthy wetlands, forests and working lands has become the
limiting factor to further economic development.
Today’s scientific studies consistently conclude that humans
are depleting Earth’s flow of natural services faster than the
flow can be regenerated, because the natural capital that
produces these services is being destroyed. For example, it
has been estimated that humans now directly or indirectly
consume up to 40% of the Earth’s Annual Net Primary
Productivity. Net Primary Productivity (NPP) is the total
biomass (forests, mangroves etc.) produced by ecosystems
through photosynthesis each year. As humans consume more
biomass, less is available for the millions of other species on
the planet, which can cause food webs to collapse and place
greater stress on the environment.
A THRESHOLD is a point at which a system
may experience a dramatic change, or
collapse. Thresholds may include heavy
rainfall triggering landslides and floods,
loss of habitat causing species extinction or
dramatic climate change.
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