Category Deep dive

Emission reduction

Global warming is directly related to the concentration (cumulative emissions) of greenhouse gases (GHG) in the Earth's atmosphere. Therefore, meeting the 1.5°C target agreed in the Paris Climate Agreement necessitates a reduction in GHG emissions to "net zero," which means achieving a balance between unavoidable emissions and their sinks (e.g., the sequestration of CO₂ in forests).

Accordingly, Germany has set itself the target of being climate neutral in 2045. Because almost 90% of Germany's GHG emissions are CO₂ emissions and the remaining 10% - mostly methane (CH4) and nitrous oxide (N₂O) from agriculture - are particularly difficult to avoid, CO₂ neutrality must already be achieved several years before climate neutrality.

Core strategies for reducing CO₂ emissions include (1) decarbonizing of the power system, (2) increasing energy efficiency, (3) electrifying end-use, and (4) switching to CO₂-free fuels.

According to the amended Climate Change Act (KSG 2021), GHG emissions must already be reduced by at least 65% from 1990 levels by 2030, and 88% by 2040. In individual sectors, fixed annual emission levels ("sector targets") must also be met by 2030; however, according to a decision by the coalition committee of the German government in March 2023, there are plans to move away from sector targets and instead take an overall view of emissions across all sectors.

By 2020, GHG emissions in the energy sector had been reduced by 54% compared to 1990, in the buildings sector by 41%, in industry by 37%, and in the transport sector by only 11%. Thus, rapid, strong, and comprehensive reductions are still needed to achieve the KSG targets, especially in sectors with low savings to date.

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Total annual GHG emissions

66% too slow Compared to the scenario Technology Mix
One-off effect
Energy crisis

Total annual GHG emissions in Germany; these are mostly energy-related CO₂ emissions from combusting fossil fuels – primarily for electricity and heat generation – and from material use of fossils in industry.

The majority of greenhouse gas (GHG) emissions in Germany are CO₂ emissions, most of which are released during the conversion of fossil fuels into electrical or thermal energy (electricity or heat) and in industrial processes (together 88% of GHG emissions in 2020). In Germany, the energy sector is responsible for just under 35% of these energy- and process-related CO₂ emissions, followed by industry and the transport sector with over 20% each, private households (15%), trade and services (5%), and agriculture (1%) (in 2020; UBA 2023).

Key points

  1. Significant and rapid reductions in CO₂ emissions are essential for achieving the 2030 climate targets and climate neutrality in 2045.
  2. The pace of CO₂ savings must roughly double for Germany to meet its 2030 climate targets.
  3. This requires an acceleration of the expansion of renewable energies (e.g. solar and wind power plants), of the ramp-up of technologies for the direct use of renewable electricity (e.g. heat pumps and e-cars) and of the phase-out of fossil energies (e.g. by phasing-out oil and gas heating systems or combustion cars).

Annual GHG emissions of the energy industry

4.9% far too slow Compared to the scenario Technology Mix
One-off effect
Energy crisis

Annual GHG emissions from the energy industry, mainly due to converting energy carriers into electricity and heat, but also for the extraction of energy sources or the production of fuels in refineries.

GHG emissions from the energy industry are strongly dominated by fossil power generation, as well as heat generation, and fuel production in refineries. Due to the rising CO₂ price in European emissions trading and the (partly) resulting decline in coal-fired power generation, emissions also fell significantly in 2015-20. In 2020, lower electricity demand as a result of the Corona pandemic and weather-related higher electricity generation from wind energy also contributed to this.

Key points

  1. In 2015-2020, GHG emissions from the power industry decreased mainly due to lower coal-fired power generation; 2021 and 2022 show a renewed increase, but this is explained by short-term special effects.
  2. Replacing fossil fuel power plants with wind and PV makes GHG savings comparatively easy to achieve in the power industry
  3. Successful defossilization of power generation is particularly relevant for climate-neutral electrification of industry, transport and building heat.

CO₂ emissions per unit of generated electricity

−23% step back Compared to the scenario Technology Mix
One-off effect
Energy crisis

CO₂ emissions from the energy industry per unit of electricity generated (minus internal demand) by combusting fossil fuels.

Climate protection scenarios consistently show that electricity is the energy source that can be decarbonized most quickly and easily. Decarbonization is illustrated by the CO₂ intensity of electricity generation: In the target scenarios, this falls to 45-130 gCO₂/kWh by 2030 (around 70 gCO₂/kWh in the lead model), compared to 330-370 gCO₂/kWh in the years 2019-21.

Key points

  1. Climate protection scenarios consistently show that electricity is the energy source that can be decarbonized most quickly and easily.
  2. Since 2015, the CO₂ intensity of electricity generation has fallen by around 20 gCO₂/kWh per year, which corresponds to the necessary decarbonization in the Ariadne target scenarios.
  3. The rapid phase-out of coal and the accelerated expansion of renewables are essential for achieving the target.

Annual GHG emissions of the transport sector

97% on track Compared to the scenario Technology Mix
One-off effect
Pandemic

In terms of KSG accounting, the indicator contains annual GHG emissions according to the source principle, i.e. GHG emissions resulting from the direct combustion of fossil fuels such as gasoline, diesel, or kerosene in the transport sector.

99% of GHG emissions from the transport sector are CO₂ emissions (UBA, 2023). In the past three decades, annual sectoral CO₂ emissions have not been reduced on average.

Key points

  1. The target paths of the Ariadne scenarios almost achieve climate neutrality in the transport sector by 2045.
  2. The scenario and model range clearly shows that further measures to reduce emissions are needed.
  3. Emissions that the transport sector as a whole emits too much must be offset by other sectors.

Annual GHG emissions of the buildings sector

88% too slow Compared to the scenario Technology Mix
One-off effect
Energy crisis

Annual GHG emissions resulting from the direct combustion of fossil fuels such as natural gas or light fuel oil in residential and commercial buildings for heating or hot water. Emissions from the construction sector, district heating or electricity generation are not included.

The Federal Climate Protection Act (KSG) sets annual permissible emission levels for the building sector. They are thus an essential benchmark for classifying the transformation of the sector. CO₂ emissions account for the majority of GHG emissions in the building sector. Compared to 2015, emissions have reduced by around 7% by 2021.

Key points

  1. GHG emissions from the building sector are a key metric for measuring the progress of the energy transition.
  2. In 2020, 2021, and 2022, the sector has missed the statutory targets of the KSG, requiring political follow-up through immediate programs.
  3. The trend to date shows significant gaps to the political targets, as well as the target paths from the Ariadne scenarios: the speed of decarbonization of the sector must increase significantly.

CO₂ emissions of residential buildings per floor space

91% too slow Compared to the scenario Technology Mix
One-off effect
Energy crisis

The indicator shows the CO₂ emissions in the building sector, resulting from the combustion of fossil fuels, like natural gas or light heating oil, for heating or hot water generation, per floor space in Germany.

The floor-specific CO₂ emissions of residential buildings have not shown a clear trend in recent years. After a reduction in 2015-2018, a significant increase was observed in 2019 and 2020, followed by another significant decrease in 2021 and 2022.

Key points

  1. CO₂ emissions per floor area show no clear development in recent years, and in particular there is no clear progress in emission prevention. - Based on the longer-term trend since 2015, there is a clear gap to the Ariadne target paths.

Annual energy and process related GHG emissions of the industry sector

146% on track Compared to the scenario Technology Mix
One-off effect
Energy crisis

Annual GHG emissions of the industrial sector resulting from the use of fossil energy sources and in chemical processes of material processing. Not included are electricity and district heating generation (see transformation sector).

This is the main indicator for the sector's climate target achievement. It serves the European and international reporting requirements, and the German government's sector target also refers to it. For a successful transformation and the achievement of the climate targets, an almost complete avoidance of GHG emissions by 2045 is necessary in addition to the interim target of 2030 (about -95% compared to 1990 or about -92% compared to 2015).

Key points

  1. The reduction of GHG emissions must be significantly accelerated.
  2. Zero emissions will probably not be achieved in the industry sector.
  3. The indicator comprises energy-related and process-related GHG emissions, which must be addressed differently.

Annual energy and process related CO₂ emissions of the industry sector per GDP

409% on track Compared to the scenario Technology Mix
One-off effect
Energy crisis

This indicator relates the annual CO₂ emissions of the industrial sector to the economy as a whole, expressed in terms of gross domestic product. It thus shows the emission intensity of the sector.

The specific CO₂ emission intensity adjusts the industry sector's CO₂ emissions for growth effects. To reach the climate targets, a strong reduction in emissions is necessary, irrespective of economic growth.

Key points

  1. The CO₂ emission intensity of industry must fall to almost zero by 2045, similarly to absolute emissions.
  2. The combination of the two indicators enables an estimate of the success of the transformation by excluding the migration of industrial value creation as a potential sole cause of emission reduction.
  3. If absolute GHG emissions and emission intensity fall, a successful transformation can be assumed by substituting emission-intensive input factors while maintaining value creation.