EMISSIONS PROJECTIONS AND UNCERTAINTY
16.Inevitably, the task of projecting emissions and
the impact of policies upon those projections is subject to a
large degree of uncertainty.[32]
This has implications for the process of developing climate change
policy. We did not set out to examine the overall accuracy of
the emissions projections themselves but a number of witnesses
did comment on the inadequacy and lack of transparency of the
information provided in the consultation paper.[33]
The Government's assessment of the impact of particular policies
was also questioned in some cases and we comment on these in the
relevant sections later in the report.
17.A sizeable number of witnesses told us of their
dissatisfaction with the quality and quantity of the information
provided in the consultation paper.[34]
Many commented to us that the contribution they could make to
the process was effectively limited by only sketchy details of
emissions projections and the methodologies used to determine
the impact of the various policies discussed.[35]
For example, the Electricity Association noted that:
"The decision to show
emissions from the energy supply industry separately and reallocated
amongst the end-use sectors is one source of confusion as is the
allocation of expected changes to landfill practice and their
effects on methane emissions"[36]
18.It is worth recognising the practical implications
of the first point. The emissions reductions from the 'energy
supply' sector are effectively shown twice: in the energy supply
sector and then shared out between the domestic and business sectors.
The Electricity Association produced a table which demonstrates
the effect of this for the domestic sector:[37]
Table 4: Carbon Dioxide Emissions from Domestic Sector
(Million tonnes Carbon equivalent)
| 1990
| 2010 |
Change |
Domestic Sector including energy supply industry
| 43 |
38 | -5
|
Domestic Sector excluding energy supply industry
| 22 |
24 | +2
|
It is unfortunate that the figures were presented
in the consultation document as shown in the first row of the
table as it undoubtedly distorts the real 'business as usual'
picture of the domestic and business sectors. The second row shows
that reductions in the energy supply industry are effectively
masking the trend of increasing emissions in the domestic sector.
This is important because by removing the energy supply figures,
it is clear that no real progress is being made in reducing emissions
from the domestic sector.
Although the Department of the Environment, Transport
and the Regions did provide details of projections to some interested
parties, the usefulness of the consultation period could have
been dramatically enhanced by including greater detail with the
paper. We believe that much greater detail of emissions projections,
methodologies and the assumptions used should have been provided
alongside the consultation paper. The lack of transparency in
the projections and some aspects of their presentation have diminished
the quality of responses. We therefore welcome the greater level
of detail provided alongside the Draft Programme. We encourage
the Government to abandon entirely the double-counting approach
in order to identify better the targets of carbon saving measures.
19.Careful thought is also required to deal with
the uncertainty in the projections and its implications for reaching
the targets discussed above. The uncertainty arises from a number
of sources: there are the underlying assumptions about economic
growth and other factors, the methodology used in modelling the
projections themselves and finally, uncertainty about how businesses
and individuals might respond to specific policies. The Department
of the Environment, Transport and the Regions noted in its memorandum
that the economic assumptions brought an uncertainty of +/- 5%
in the projection of emissions for 2010 with a further +/-5% as
a result of changes in inventory methodology and an error of +/-20%
in the impacts of policies upon emissions.[38]
One of the implications of all this uncertainty is that the Government
should allow a margin of error in introducing policies to reduce
emissions to meet the emissions reduction targets.[39]
To establish how much 'headroom' is required, further work must
be carried out to assess the uncertainty and sensitivity of the
emissions projections and policy impacts. We hope that the Government
is fully aware of this problem and look forward to publication
of the details of this analysis and the amount of 'headroom' which
is being allowed to ensure that the emissions reduction targets
will be met. Further, regular monitoring of emissions and comparisons
with the projections should be used to refine and refocus climate
change policies where necessary.
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