Ecological Economics 30 1999 317 – 331
ANALYSIS
Accounting for nitrogen in Denmark — a structural decomposition analysis
Mette Wier
a,
, Berit Hasler
b
a
AKF, Danish Institute of Local Go6ernment Studies, DK-L
602
Copenhagen, Denmark
b
National En6ironmental Research Institute, Department of Policy Analysis, P.O. Box
358
, DK-
4000
Roskilde, Denmark Received 18 March 1998; received in revised form 20 August 1998; accepted 6 January 1999
Abstract
This paper examines the environmental-economic cycle for nitrogen in Denmark based on nitrogen input and output from different economic sectors. An input-output model is employed together with a nitrogen mass balance
to apportion total nitrogen loading by final demand and estimate export and import of nitrogen from foreign trade. The changes in agricultural and industrial nitrogen loading from the mid 1960s to the late 1980s are broken down into
changes related to different technological and economic factors. The analysis reveals that technological change intensified agricultural production and economic growth especially rising exports are the key factors, structural
shifts changes in commodity mix in the household and production sectors generally being of less importance. © 1999 Elsevier Science B.V. All rights reserved.
Keywords
:
Marine nitrogen loading; Nitrogen mass balance; Decomposition analysis; Input-output modelling www.elsevier.comlocateecolecon
1. Introduction
Nitrogen loading of the Danish aquatic envi- ronment has increased in recent decades, giving
rise to serious problems with eutrophication of inland and marine waters throughout the 1980s.
In the Øresund, the Kattegat and the Belt Seas, increases in the winter concentration of nitrogen
were observed from the mid 1970s to the mid 1980s, in many cases leading to oxygen deficit
1
Danish Environmental Protection Agency, 1984; Christensen et al., 1994. In 1984, the Danish
Environmental Protection Agency reported an oxygen deficiency in areas where it had not previ-
ously been detected, including in the North Sea
1
In Denmark, the term ‘oxygen deficit’ is used when the water oxygen concentration falls below 4 mgl. If the concen-
tration falls below 2 mgl, the term ‘severe oxygen deficit’ is used. Many fish species flee from areas affected by oxygen
deficiencies. In the case of a prolonged severe oxygen deficit, benthic invertebrates that are unable to flee eventually die.
Corresponding author. Tel.: + 45-33-11-03-00; fax + 45- 33-15-28-75.
E-mail address
:
mwakf.dk M. Wier 0921-800999 - see front matter © 1999 Elsevier Science B.V. All rights reserved.
PII: S 0 9 2 1 - 8 0 0 9 9 9 0 0 0 0 4 - X
and other open marine waters Danish Environ- mental Protection Agency, 1984. The frequency of
the recorded episodes of oxygen deficit was also found to have increased. Both the extent and
frequency of oxygen deficit have increased even more during the late 1980s, this being attributable
to the increase in nitrogen loading of the aquatic environment National Environmental Research
Institute, 1990 – 1997.
The increase in nitrogen loading is attributable to increased production in the agricultural sector
and growth in the amount of sewage effluent. The latter is the result of enhanced population growth
and increased industrial production. The major part of the increase is attributable to increased
agricultural production resulting from general in- tensification of production and to a lesser extent to
the incorporation of marginal land in production Christensen et al., 1994.
The negative environmental consequences of enhanced nutrient loading of the Danish aquatic
environment led Parliament to adopt the Action Plan on the Aquatic environment in 1987 Dub-
gaard, 1990; Rude and Frederiksen, 1994. Among other things, this stipulated that nitrogen discharge
from agricultural sources was to be reduced by
50 while discharges from other sources indus- try, sewage works were to be reduced by 60.
The present article quantifies the change in marine nitrogen loading due to intensification of
agricultural production, general economic growth and general structural shifts in the economy over
two decades from 1965 to 1989. The purpose of this paper is to analyse the background for the serious
situation at the end of the 1980s and place it in a historic perspective with a view to identifying the
main shifts in the agricultural sector and economy that have been responsible for this change in
loading. The intention is to identify the factors responsible for the development and quantify their
respective contributions. The analysis follows a top-down approach, focusing on the main tenden-
cies on both the environmental and economy sides.
The analysis is made at the national level because the political goals are set at this level. Nitrogen
loading is generally too high in the majority of the inner Danish marine waters and the adjoining
marine waters
2
Christensen et al., 1994, and the political goal of halving nitrogen loss applies uni-
formly to the whole country. An analysis at the national level is therefore meaningful.
The analysis was carried out by combining an input-output model with a nitrogen budget for
agriculture and emission factors for sewage effluent. This comprehensive integrated model sys-
tem enables behavioural and technological shifts in the household and production sectors to be related
to changes in nitrogen loading, thereby revealing the economic reasons for the development.
This study distinguishes itself by relating nitro- gen loading to the whole economy, i.e. to produc-
tion as well as consumption activities, and by applying input-output structural decomposition
analysis on a new area. Furthermore, it covers a very long period, analysing input-output tables
from 1966 to 1988, whereby it is possible to examine changes during three separate decades. A final
distinguishing feature is that the study includes an assessment of the importance to nitrogen loading
of foreign trade.
2. Model and data
