TOTAL SULPHUR DIOXIDE EMISSIONS AND EMISSIONS FROM ENERGY PROCESSES

    Panel 1
    Update date
    Authors

    Antonio Caputo, Riccardo De Lauretis, Francesca Palomba

    Abstract
    Graph
    Abstract

    The indicator concerns atmospheric emissions of sulfur dioxide (SO₂), a primary precursor of acidification processes. Sulfur dioxide emissions originate predominantly from energy-related activities. In 2023, such activities accounted for 92.1% of total SO₂ emissions. These emissions primarily result from the combustion of fossil fuels (including power generation plants, residential heating systems, and transport). Mitigation of SO₂ emissions can be achieved through improvements in fuel quality and/or via flue gas treatment technologies. The reduction in SO₂ emissions from energy-related processes (−96.1% in 2023 compared to 1990 and −98.1% compared to 1980), attributable to the use of low-sulfur fuels and the deployment of emission abatement systems, has thus far ensured compliance with international protocols addressing acidification. Overall SO₂ emissions in 2023 were 82.5% lower than those recorded in 2005.

    Description

    The indicator refers to atmospheric emissions of sulphur dioxide (SO₂), which are a primary cause of acidification processes. Sulphur dioxide emissions originate essentially from the use of fossil fuels (power generation plants, residential heating, and transport); they can be reduced by improving fuel quality and/or through the treatment of process gas effluents.

    Purpose

    To assess the role of energy processes in relation to sulphur dioxide emissions, with the aim of reducing the contribution of energy use to air pollution.

    Policy relevance and utility for users
    It is of national scope or applicable to environmental issues at the regional level but of national significance.
    It is able to describe the trend without necessarily providing an evaluation of it.
    It is simple and easy to interpret.
    It is sensitive to changes occurring in the environment and/or human activities
    It provides a representative overview of environmental conditions, environmental pressures, and societal responses.
    It provides a basis for international comparisons
    It has a threshold or reference value against which it can be compared.
    Analytical soundness
    Be based on international standards and international consensus about its validity;
    Be theoretically well founded in technical and scientific terms
    Presents reliability and validity of measurement and data collection methods
    Temporal comparability
    Spatial comparability
    Measurability (data)
    Adequately documented and of known quality
    Updated at regular intervals in accordance with reliable procedures
    Readily available or made available at a reasonable cost/benefit ratio
    An “adequate” spatial coverage
    An “appropriate” temporal coverage
    Main regulatory references and objectives

    Directive 2001/81/EC, transposed into Italian law by Legislative Decree No. 171 of 2004, set the national SO₂ emission ceiling to be achieved by 2010 and maintained in subsequent years at 475 kt. The Directive represents the EU transposition of the 1999 Gothenburg Protocol aimed at combating acidification, eutrophication, and ground-level ozone.

    Directive 2001/81/EC was repealed by Directive (EU) 2016/2284, transposed in Italy through Legislative Decree No. 81 of 2018, which established new national SO₂ emission reduction commitments. Unlike the previous legislation, the target is no longer expressed in absolute value, but as a percentage reduction: a 35% reduction from 2005 levels for any year from 2020 to 2029, and a 71% reduction from 2005 levels starting in 2030.
     

    DPSIR
    Pressure
    Indicator type
    Descriptive (A)
    Performance (B)
    References

    ISPRA, Quality Assurance/Quality Control Plan for the Italian Emission Inventory, Several years, https://emissioni.sina.isprambiente.it/inventario-nazionale/

    ISPRA, Informative Inventory Report, Several years, https://emissioni.sina.isprambiente.it/inventario-nazionale/
     

    Limitations

    The relevance of the indicator decreases when moving from the national to the local level, due to the uneven distribution of energy production and consumption across the national territory.

    Data source

    ISPRA (Istituto Superiore per la Protezione e la Ricerca Ambientale)

    Data collection frequency
    Yearly
    Data availabilty

    ISPRA, Atmospheric Emissions Inventory, https://emissioni.sina.isprambiente.it/inventario-nazionale/

    Spatial coverage

    National

    Time coverage

    1980-2023

    Processing methodology

    Estimate carried out within the framework of the preparation of the national emissions inventory. To calculate data at regional and provincial levels, certain information must be estimated in the absence of specific statistical surveys.

    Update frequency
    Year
    Data quality

    The estimates are calculated in accordance with the principles of transparency, accuracy, consistency, comparability, and completeness, as required by the reference methodology for the development of the National Atmospheric Emissions Inventory. Data are available at the national level.

    Status
    Good
    Trend
    Positive
    State assessment/description

    The NEC Directive (2016/2284) established national sulfur dioxide (SO₂) emission reduction targets for each year from 2020 to 2029, as well as for any year from 2030 onwards. Specifically, for Italy, the 2023 target was set at 267.16 kilotonnes (kt) of national SO₂ emissions, corresponding to a 35% reduction compared to 2005 levels. The 2030 target is set at 119.20 kt of national SO₂ emissions, equivalent to a 71% reduction compared to 2005, and has already been achieved.

    In 2023, the energy sector was responsible for emitting 66.1 kt of SO₂ into the atmosphere, accounting for 92.1% of the national total (Table 1). This represents a reduction of 83.3% compared to 2005 levels, thereby playing a key role in achieving the prescribed emission reduction target.

    Trend assessment/description

    The reduction in sulfur dioxide (SO₂) emissions from energy-related processes (−96.1% in 2023 compared to 1990 and −98.1% compared to 1980), driven by the use of cleaner fuels and energy carriers, has so far ensured compliance with international protocols on acidification.

    Comments

    Sulfur dioxide (SO₂) emissions originate predominantly from energy-related processes. In 2023, these processes accounted for 92.1% of total national SO₂ emissions. The decrease in the sulfur content of fuels used in energy production, along with the implementation of more effective emission abatement systems, is reflected in the declining relative contribution of energy-related processes to total SO₂ emissions—from 98.6% in 1997 to 92.1% in 2023 (Table 1 and Figure 1).
    It should be noted that, in order to ensure consistency and comparability of the inventory, the annual update of emissions entails a revision of the entire historical time series based on the most up-to-date information and methodological developments.

    Data
    File
    Headline

    Table 1: Total sulfur dioxide emissions and emissions from energy-related processes (a)

    Data source

    ISPRA

    Data legend

    (a) Excluding emissions from natural sources (e.g., volcanoes)

    Immagine
    Headline

    Figure 1: Total sulfur dioxide emissions and emissions from energy-related processes (a)

    Data source

    ISPRA

    Data legend

    (a) Excluding emissions from natural sources (e.g., volcanoes)

    Graph
    English