Sammendrag
Purpose Habitat destruction is today the most severe threat to
global biodiversity. Despite decades of efforts, there is still no
proper methodology on how to assess all aspects of impacts
on biodiversity from land use and land use changes (LULUC)
in life cycle analysis (LCA). A majority of LCA studies on
land extensive activities still do not include LULUC. In this
study, we test different approaches for assessing the impact of
land use and land use change related to hydropower for use in
LCA and introduce restoration cost as a new approach.
Methods We assessed four hydropower plant projects in planning
phase (two upgrading plants with reservoir and two new
run-of-river plants) in Southern Norway with comparable geography,
biodiversity, and annual energy production capacity.
LULUC was calculated for each habitat type, based on mapping
of present and future land use, and was further allocated
to energy production for each power plant. Three different
approaches to assess land use impact were included: ecosystem
scarcity/vulnerability, biogenic greenhouse gas (bGHG)emissions, and the cost of restoring affected habitats.
Restoration cost represents a novel approach to LCA for measuring
impact of LULUC.
Results and discussion Overall, the three approaches give
similar rankings of impacts: larger impact for small and new
power plants and less for larger and expanding existing plants.
Reservoirs caused a larger total area affected. Permanent infrastructure
has a more similar absolute impact for run-of-river
and reservoir-based hydropower, and consequently give relatively
larger impact for smaller run-of-river hydropower. All
approaches reveal impacts on wetland ecosystems as most
important relative to other ecosystems. The methods used
for all three approaches would benefit from higher resolution
data on land use, habitats, and soil types. Total restoration cost
is not accurate, due to uncertainty of offset ratios, but relative
restoration costs may still be used to rank restoration alternatives
and compare them to the costs of biodiversity offsets.
Conclusions The different approaches assess different aspects
of land use impacts, but they all show large variation of impact
between the studied hydropower plants, which shows the importance
of including LULUC in LCA for hydropower projects.
Improved data of total restoration cost (and cost accounting)
are needed to implement this approach in future LCA.
bGHGemission . Ecosystemscarcity/
vulnerability . Land use change impact . Life cycle assessment
(LCA) . Mitigation hierarchy . Restoration cost
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