Page 383 - Design for Environment A Guide to Sustainable Product Development

358 C h a p t er T w enty

example, one worrisome side effect of increasing atmospheric levels
of carbon dioxide is ocean acidification, which could cause corals
to go extinct. If corals cannot adapt, the cascading effects in reef eco-
systems will reduce global biodiversity and threaten food security
for hundreds of millions of people dependent on reef fish [2].
A 2007 study, published by the National Academy of Sciences,
showed that global CO emissions from fossil-fuel burning and
2
industrial processes have been accelerating, with their growth rate
increasing from 1.1% per year for the decade 1990–1999 to more than
3% per year for the period 2000–2004 [3].The observed rise in world-
wide greenhouse gas emissions since 2000 can be attributed to in -
creases in both the energy intensity of production as well as the
carbon intensity of energy generation (see Chapter 18), coupled with
continuing increases in population and per-capita gross domestic
product (GDP). Not surprisingly, the growth rate in emissions has
been strongest in rapidly developing economies, particularly China.
The economic recession of 2008–2009 may have caused a temporary
lull, but the long-term pattern is alarming.
The overall ecological burdens of global economic growth can be
understood from the following equation, which is a generalization of
the well-known Kaya identity [4].
Total burden = population × ($GDP / capita) × (resources / $GDP)
× (burden / resource unit)
The same equation holds whether the resources are fossil fuels
and the burdens are greenhouse gas emissions, or whether the re -
sources are material flows and the burdens are ecosystem service
degradation. The first two factors are inexorably rising; and even if
population growth slows, the GDP per capita will most likely con-
tinue to rise in developing nations. Yet scientific projections indicate
that we need to sharply reduce our overall emissions and waste in
order to stabilize atmospheric CO concentrations and protect natural
2
capital. Therefore, the focus of sustainability strategies needs to be on
the latter two factors:

1. Resource intensity (resources/$GDP) can potentially be
reduced by decoupling material and energy throughput from
economic growth. This is as much a behavioral challenge as it
is a technological challenge. Despite improvements from
1970 to 2000, resource intensity seems to be flattening out,
and could even begin to rise again as personal wealth in -
creases in developing nations. Dematerial ization strategies
(see Chapter 8) are the best avenue for achieving further
reductions in this factor.
2. Burden intensity (burden/resource unit) can potentially be
reduced through process innovations; for example, the