Emissions
of nitrous oxide (N2O)
CC-3
Climate
Change
Pressure
1 Indicator
definition and unit of measurement
Total
anthropogenic nitrous oxide (N
2O)
emissions from the sectors energy, industrial processes, solvent and other
product use, agriculture, land use change and forestry, and waste (as defined
by the IPCC
[7]).
Natural emissions are not accounted for in this indicator. The unit of
measurement is tonnes N
2O
per year.
2 Placement
in the framework
5EAP:
Chapter
5: The themes and targets of the programme, section 5.1: Climate change.
Agenda
21:
Chapter
9: Protection of the atmosphere, section 2: Conservation and management of
resources for development.
International
conventions and agreements:
UNFCCC
(New York, 1992).
Ranking:
Core
ranking:
3
(49%)
Policy
Relevance:
3
(3.0)
Analytical
Soundness:
3
(3.0)
Responsiveness:
11
(2.6)
Most
appropriate related state indicator:
Atmospheric
nitrous oxide concentrations, global temperature.
3 Significance
Purpose:
N2O
is one of the major greenhouse gases. The main purpose of this indicator is to
monitor total anthropogenic N
2O
emissions.
Relevance:
Although
total N
2O
emissions are relatively small in comparison with total CO
2
emissions, the radiative forcing capacity of N
2O
is relatively large. The Global Warming Potential for N
2O
amounts to 310, assuming a 100 years time horizon
[8]. See
also 3. Relevance of the Methodology sheet for CO
2.
Linkages
to other pressure indicators:
The
indicator is linked to the indicators of other greenhouse gases. Furthermore,
the indicator is linked with those in the area of Ozone Depletion. Due to the
long lifetime of N
2O,
N
2O
emissions can reach the stratosphere and affect the destruction of the ozone
layer, see the methodology sheet for N
2O
in the Ozone Depletion section (OD-9).
Moreover,
ozone is also a greenhouse gas, and therefore changes in stratospheric ozone
should be considered in assessing climate change.
Targets:
The
current target for industrialised countries is to aim at returning emissions to
1990 levels in the year 2000. Current commitments of EU Member States add up to
a 10% reduction of CO
2,
CH
4
and N
2O
emissions
[9]
by 2010 (reference year 1990).
4 Methodological
description and underlying definitions
Underlying
definitions and concepts:
The
main sources of anthropogenic N
2O
are intensive agriculture using high levels of fertilisers, and a number of
industrial processes. Natural sources are poorly quantified, but are probably
twice as large as anthropogenic sources. Natural emissions are not accounted
for in this indicator.
Measurement
methods:
The
1996 “Guidelines for National Greenhouse Gas Inventories” have been
formally adopted by the IPCC as the international method to estimate emissions.
Limitations
of the indicator:
The
uncertainty in estimates of N
2O
emissions is relatively large.
Alternative
definitions:
An
aggregated indicator for CO
2,
CH
4,
and N
2O
emissions based on their Global Warming Potential.
[7]
Intergovernmental
Panel on Climate Change
[8]
IPCC
second assessment report, 1996
[9]
Weighted
total, using Global Warming Potentials with a 100 year time-horizon.
