7 Conclusions

Earlier analyses of the costs of reducing UK emissions of SO₂, NO_x, VOCs and NH₃ have been carried out by IIASA using the RAINS model. The estimated costs of meeting the J1 and H1 scenario emissions were £447M and £899M, respectively. This study has aimed to produce a more detailed analysis by using the latest available datasets and specifically UK-based models, with much higher spatial resolution. The costs of the J1 and H1 scenarios have been estimated in this study to be £145-158M and £516-529M respectively, with the range being due to uncertainties in ammonia abatement costs (in particular whether or not urea substitution will be allowed). In addition, the cost of meeting the emissions ceilings for the UK negotiated at the 31^st Session of the UNECE Working Group on Strategies, on 2^nd September 1999, has been estimated to be £61M.

The regional splits of costs for each scenario are shown in Table 29. The uncertainty with respect to ammonia abatement measures has a substantial influence on the costs in Northern Ireland and Wales under the J1 scenario.

Table 29. Costs by region (£M/year).

Scenario	England	N. Ireland	Scotland	Wales	Offshore
WGS31c	41	1	8	3	7
J1	108 – 116	4 – 6	16 – 18	7 – 9	8
H1	339 - 347	11 – 13	68 - 71	19 - 21	77

The split in costs between the different pollutants is shown in Table 30. In terms of overall cost, the role played by NO_x and NH₃ abatement is relatively small. The costs of VOC abatement become more significant as a fraction of the total as one goes down the table, and provide more than 80% of the costs under the H1 scenario (compared to only 42% under J1, and about 27% for WGS31c).

Table 30. Costs by pollutant (£M/year).

Scenario	SO2	NOx	VOC	NH3*	Total
WGS31c	34	9	18	0	61
J1	61	9	64	11 – 24	145 – 158
H1	61	9	435	11 - 24	516 – 529

^*Abatement costs for ammonia emissions are shown as a range because of uncertainty about the acceptability of urea substitution, the higher end of the range assuming that it is not adopted.

As noted in earlier work, for example the review of the NAQS, there are many benefits linked to abatement of the four pollutants considered here. These benefits accrue to health, natural ecosystems, buildings, crops, forests and so on. The key indicators of benefit are summarised below, these being the effects that can be described with most confidence.

Table 31. Key benefits of each scenario, with results showing the total annual benefit to the UK of abatement across the UNECE region (except for H1, where only EU countries participate). All monetised values in 1990£/year.

	1990	UKREF	J1	H1	WGS31c
Ecosystem area (%) subject to critical load exceedence for:
Acidification	43%	11%	5.4%	6.2%	9.2%
Eutrophication	11.2%	2.0%	1.0%	1.1%	1.3%
Change from UKREF in damage to:
Crops (£million)			£10M	£17M
Materials (£million)			£15M	£15M	£5M
Premature mortality (cases)			540	530	160
Respiratory hospital admissions			350	380	110

This takes the analysis to the same point as the assessment carried out for the NAQS. However, it is possible to go further, although subsequent analysis is subject to a higher level of uncertainty. Based on these results, and uncertainty with respect to the valuation of acute effects of air pollution on mortality, it is logical to ask how large the value of statistical life (the unit value for a case of mortality) would need to be for benefits overall to match costs. Considering only acute effects on mortality, damage to crops and buildings, the following results arise, all expressed in 1990£:

Scenario J1: £190,000 to £350,000

Scenario H1: £820,000 to £1,500,000

Results for H1 are similar to the upper point identified by EAHEAP, and for J1 in-between the EAHEAP upper and intermediate points

Ranges were ascribed to the key variables in the assessment, leading to a broad range in estimated benefits. Costs tended to lie between the upper and lower bounds for benefits – a clearly inconclusive result. However, assessment of benefit-cost ratios suggests that costs for J1 tend to be towards the lower end of the range, in other words, there appears a reasonable likelihood that the real benefit would exceed the estimated costs. This is not the case for H1, however, where the bias is the other way round, with costs towards the upper end of the benefits range. It should be remembered that there are a number of benefits that have not been quantified in monetary terms, and hence are outside this part of the analysis – including damage to ecosystems and cultural heritage (cathedrals, etc.).

The overall view on an appropriate position for the UK to take in negotiation is clearly a political question, particularly given the uncertainties identified in this report. Our role is not to pre-empt any political decision by (for example) introducing our own interpretation of the precautionary principle. It is hoped that the methods developed here for presenting information on uncertain impacts will prove useful, and provide real assistance to decision makers.

Chapter 6          Chapter 8