Impact decoupling requires
increasing economic output while reducing negative environmental impacts. Such
impacts arise from the extraction of required resources (such as groundwater
pollution due to mining or agriculture), production (such as land degradation,
wastes and emissions), the use phase of commodities (for example transport
resulting in CO2 emissions), and in the post-consumption phase (again wastes
and emissions). Methodologically, these impacts can be estimated by life cycle
analysis (LCA) in combination with various input-output techniques. Impact decoupling means that negative environmental impacts decline
while value is added in economic terms. On aggregate system levels such as a
national economy or an economic sector, it is methodologically very demanding
to measure impact decoupling, because many environmental impacts need to be
considered, their trends may be quite different or not even monitored across
time, and system boundaries as well as weighting procedures are often
contested.
THE ABC FOR SUSTAINABLE CITIES
UNEP / UN HABITAT / FIDIC / GI-REC
Based on