Therefore, the isolated results for each of the three treatment options could be further summarised across studies
by taking into account the relative differences in the configuration of each study. In spite of the absence of
alternative options, well documented results were produced for landfill, recycling and incineration individually. In
most impact categories and the majority of cases, landfill was proven to be the least preferable
option. Some fluctuations in the classification of landfill can be explained by the choice of parameters of the
system.
The comparison between incineration and recycling is more complex. In most impact categories
(depletion of natural resources, climate change, primary energy, eutrophication, photochemical oxidation, non-
treated waste, ecotoxicity, human toxicity and ecotoxicity in water), it is difficult to establish a relative
preference as there is inconsistency among the studies. In some impacts, there is a clear superiority of one
option (water consumption, acidification, ecotoxicity in sediments and ecotoxicity in soil). If a summary of the un-
weighted impact potentials is attempted, recycling might have a slight superiority. However, the importance of
each impact indicator is dependent on the scope of each LCA and an ad hoc comparison of the sums is ill-
advised.
The absence of an elementary sensitivity analysis in most studies is a barrier to determining the real hotspots in
the life-cycle of waste paper, but some important parameters are mentioned or can be located through the
results.
Since the benefits attributed to the paper waste management system are strongly associated with energy
savings, one of the most important parameters is the electricity mix. Especially for some impacts, such as
global warming, the origin of the fuels used for energy production can be decisive for the results. Therefore, the
geographical scope of the system as well as the expansion of the system should be very clearly defined. This
choice also gives an indication about the type and level of technologies used, together with the relevant
efficiencies. As described in the section 3.2.3, not all results can be explained by a sole parameter. Therefore,
although all studies stress the importance of the energy mix, the synergies and combinations of factors might
influence the results in an unpredicted manner. The interpretation of a life cycle impact assessment should take
into account all the parameters that affect the overall results.
Moreover, not many studies dealt with the issues of carbon sequestration/storage, land use change or
alternative use of wood. The complexity of this issue and the variety of assumptions that are associated with
it, prevented the LCA teams from including them. Since these processes produce high indirect emissions, the
benefits attributed to the system are not fully accounted for and the results in these cases are, to a certain
degree, underestimated.
3.2.5 Comparison with the results from the previous report edition
The previous WRAP report included paper in the selected fractions. This report only analyses studies that have
been published since the previous report and therefore functions as supplementary to the previous conclusions.
The overall situation has not changed significantly with the inclusion of new LCAs. The general idea that landfill
is, in most cases, the worst option is maintained. However, the results of comparing recycling to incineration are
less concrete than in the previous report, where recycling had a slight advantage. Most probably the
advancements in incineration technologies (mainly energy recovery efficiencies) have been integrated to the
recent LCAs. In this new group of studies, there is no case where incineration is used as a disposal option with no
energy recovery, as opposed to the previous report where two out of nine studies do not include energy recovery
from incineration at all. Three out of five studies include heat production from incineration as well. On the other
hand, there was no analysed study that took into account the alternative use of the incineration capacity, a factor
that was deemed quite decisive in the previous study.
The comparison between incineration and landfill is quite well documented in this review, as many studies include
it. In most cases and for most environmental indicators, incineration performs better. A more comprehensive
picture is thus built, while the previous study only identified one study with this comparison, which showed a
clear preference for incineration.
Regarding the most influential parameters, the issue of alternative use of wood thanks to the wooden resources
saved in case of recycling has not been assessed at all in the recent studies. The old report included one LCA that