1. Making climate neutrality operational

The Hamburg Chamber of Commerce (HCC, Box 1.1) has set the target to reach climate neutrality by 2040 for its member businesses. This report aims to identify key actions the businesses in Hamburg need to undertake as well as key challenges they need to face to develop business models consistent with this climate neutrality objective. As the report highlights, building the transformations on the specific regional economic context is key to addressing challenges and opportunities and requires businesses to work together. This report will argue that businesses should anticipate policy action to be better prepared for the major transformations, to save unnecessary costs and be in a better position to address challenges and seize opportunities. While it is not directed at policymakers, some references will be made to how policy can support the Hamburg business community to best face their challenges and take advantage of opportunities.

This chapter will start off with making the target operational for the business community. The first section discusses how businesses should interpret the target. It needs to be coherent with the national and international targets that will in due course bind Hamburg businesses, notably climate neutrality targets in the EU, Germany and Hamburg.

The second section provides an overview of available data on Hamburg’s greenhouse gas (GHG) emissions and economic activity as well as their sectoral composition, laying out how the city’s economic sectors will be concerned.

The third section provides an overview of the climate targets and action plans in three selected, comparable cities in Europe and North America, Rotterdam, Stockholm and Seattle. These cities have similar climate targets and face similar challenges. Businesses in Hamburg can learn from climate actions undertaken in these cities. Their business communities can cooperate with Hamburg’s to reach their climate objectives. These cities are also competitors: Businesses in Hamburg need to make sure they do not fall behind in identifying opportunities and challenges.

Climate action can generate important wellbeing co-benefits, such as reduced air pollution or traffic congestion. Co-benefits materialise more quickly than climate benefits. They often exceed the local costs of climate action. Since many of these co-benefits arise locally and require local action, they can contribute to making regions more attractive and competitive and be a powerful motivator of local climate action. This issue is picked up in the final section of this chapter and illustrated with the example of urban passenger transport.

For the purposes of this report, the objectives of reaching climate neutrality and reaching net-zero GHG emissions will generally be used interchangeably. Most global warming is caused by long-lived GHG emissions, notably CO2. These will need to be brought to net zero to halt global warming, as it is their cumulation in the atmosphere that determines global warming. Short-lived emissions, notably methane, may not need to reach net zero but still need to be halved by 2050 worldwide to be able to limit global warming to 1.5 degrees (Intergovernmental Panel on Climate Change, 2018[1]). The Hamburg territory emits little methane emissions. Still, methane plays an important role in the value chains of some Hamburg businesses.

The resource cost of reaching net zero GHG emissions by 2050 in high-income countries with modest fossil-fuel extraction and processing may amount to up to 1-2% of GDP (UK Committee on Climate Change, 2019[2]) Costs are concentrated on the last 10 - 20% of emissions abatement. The resource cost refers to the net resources that need to be devoted to the transition, including investment (European Commission, 2018[3]; OECD, 2017[4]). The impact of resource costs on the competitiveness of sectors subject to international competition depends on who bears them. Such sectoral competitiveness impacts may be particularly relevant if climate policies proceed at unequal speed across countries or regions. For example, if taxpayers assume resource costs, competitiveness in sectors subject to international competition may be largely preserved, and resources would not need to be reallocated to other sectors or geographies. When such reallocation occurs, it could further impact the distribution of economic activity across regions.

Early action is important for the climate but also to avoid unnecessary economic costs of delayed action. They can be large. The costs of delaying action to reduce GHG to meet the target of 1.5°C may be USD 5 trillion per year worldwide or 7% of the annual world GDP (Sanderson and O’Neill, 2020[5]). For Germany, net mitigation costs have been estimated to increase by an average of 40% for each decade of delay (Council of Economic Advisers, 2014[6]). A major source of additional costs from delayed action are investment decisions, especially for long-lived capital goods, that are inconsistent with climate objectives and which therefore need to be written off before their economic end of life (“stranded assets”) These risks are particularly large in capital-intensive and energy-intensive activities, such as manufacturing activities (OECD, 2017[4]; OECD, 2023[7]). Further costs from delayed action arise from higher adjustment and coordination costs. Higher costs result because later reductions will require faster expansion of new technologies, raising susceptibility to errors (Chapman, 2019[8]).

The Hamburg economy will need to contribute to reaching net zero GHG emission targets in the European Union (EU), Germany and in the region (Land) of Hamburg. All three jurisdictions have set targets with legal force. The legal force of climate policy commitments is increasingly taken into account in court decisions in Germany and elsewhere. Meeting the HCC’s climate neutrality objective should therefore serve Hamburg businesses to meet these legally enshrined emission targets, in terms of ambition and scope. It should also take into account the strong integration of Hamburg into the global economy.

The HCC’s climate neutrality target is somewhat more ambitious in timing than the region’s, Germany’s and the European Union’s (EU). Intermediate objectives are important to ensure early action and thereby give credibility to the climate neutrality objectives. Germany and the EU share a mid-term target with Hamburg’s regional government: to reduce GHG emissions by at least 60% compared to 1990 levels by 2030. The Hamburg government aims to reduce CO2 emissions by 70% below 1990 levels by 2030. The HCC has not set an intermediate target for its businesses, on aggregate or sectorally. Hamburg and Germany have sectoral decarbonisation targets with corresponding action plans to achieve them, though they have different categories of sectors. Power supply and buildings are expected to decarbonise the most quickly by 2030, relative to 1990 (Table 1.1). Hamburg businesses will need to lead the transformations required to reach climate neutrality – knowing that climate action is, currently, still far behind. They should be implementing transformations more quickly than other sectors, such as private households in Hamburg, as well as more quickly than other businesses in Germany and the EU. The Hamburg Port Authority has already set the target of climate neutrality for 2040 in port operations.

The emissions coverage of the EU and German targets provides critical information on what emissions the climate neutrality objective should cover for the Hamburg business community. Both the EU and Germany define the emission objectives in terms of Scope 1 emissions (Box 1.2). These include all direct GHG emissions generated within their geographical boundary. The Hamburg region’s target includes emissions from energy end use, including both Scope 1 and Scope 2 emissions. It does not include emissions on Hamburg territory from energy transformation, notably from the generation of electricity and oil refining. Consistent with this approach, local emissions from heat and electricity generation are attributed to end-users, even where electricity and heat are generated outside city borders.

The EU requires the net-zero GHG emissions objective to be reached on domestic emissions. The purchase of emission reductions outside the EU does not count towards this target. The EU will contribute to financing emission reductions outside its borders but doing so will be additional to its net zero objective. German legislation does not exclude contributions from international offsets to reach its targets, but the government’s political intention appears to keep its role small.

The EU and Germany also limit the role of carbon dioxide removal (CDR) to contribute to emission reductions. CDR can contribute to emission reduction by absorbing emissions durably elsewhere than in the atmosphere. Two main avenues are through land use and land use change as well as through carbon capture, use and storage (CCUS). Worldwide, the share of emissions that could be offset with CDR may be less than 20% and should therefore be limited to offsetting residual emissions in hard-to-decarbonise activities (Buck et al., 2023[18]).

The International Maritime Organisation (IMO) has adopted an objective to net zero GHG emissions in international shipping by 2050, although the role of offsets is unclear (Chapter 3). They account for 3% of the total GHG emissions worldwide (International Maritime Organization, 2020[19]). With regards to international aviation, emissions of extra-EU flights departing from EU territory are included in the EU’s climate objectives based on fuel purchased domestically (German Presidency of the Council of the European Union, 2020[20]). International flights within EU territory are included in the European Emissions Trading System (EU ETS) (European Commission, 2021[21]). However, Germany and Hamburg do not include international aviation in emissions reductions in order to better reflect the local climate policy impact.

Hamburg is a highly internationally connected economy. Hence, the 2040 climate neutrality objective of the HCC needs to be placed in the broader context of worldwide climate objectives. Most OECD countries have adopted net-zero emission targets by 2050, although some have limited net-zero targets to CO2 emissions and have given international offsets and CDR a bigger role. China aims to achieve net zero GHG emissions before 2060. India aims to reach net zero by 2070.

Businesses will trade with partner countries that will also need to reach climate neutrality, albeit possibly later. Businesses will need to transform purchases of intermediate goods and services from trading partners to take into account progress towards climate neutrality which is necessary also in other countries. Moreover, policy action is likely to require that imported goods and services meet increasingly stringent requirements on the emissions generated in production. The European Union has taken the first steps in this direction with its carbon border adjustments and the regulation of deforestation-free imported products (Chapter 2). Since Hamburg is a major trading hub with a major international port, understanding the GHG emissions embedded in the goods and services involved in this trade is particularly important for businesses in Hamburg. This international context is essential to understand business opportunities and challenges they face in the transition to climate neutrality.

This discussion of emission targets has the following implications for making the HCC climate neutrality target operational:

The climate neutrality objective set by the HCC should include reaching net zero GHG emissions for all direct (Scope 1) and indirect emissions from the use of electricity and heat (Scope 2 emissions) of businesses at least on the territory of Hamburg by 2040. Scope 1 emissions of Hamburg businesses generated elsewhere in Germany or on EU territory should reach net zero by 2045 and 2050 respectively. With power supply largely determined by German or EU production, which will largely be decarbonized by 2040, and district heat supply in Hamburg, Hamburg businesses should purchase all electricity and heat from zero-emission sources by 2040.

  • The HCC and its businesses should not rely on major international offsets to reach climate neutrality objectives. International emission offsets may be reasonable between 2040 and 2050 for those business Scope 1 emissions on Hamburg territory that Hamburg businesses may only bring to net zero by 2050 but not by 2040. This could be particularly relevant for difficult-to-decarbonise sectors, including emission-intensive manufacturing. Scope 1 emissions should reach net zero without any international offsets by 2050 at the latest.

Emission reductions through carbon sinks should play a minor role. The use of CCS should be limited to process emissions in industry. Offsetting Scope 1 emissions on a small scale could also include financing LULUCF carbon sinks in other EU countries, but these should broadly be limited to the EU LULUCF target contribution share.

Hamburg businesses should include indirect emissions in climate neutrality targets. Taking into account scope 3 emissions at the individual business level will allow to fully integrate opportunities and challenges from reaching climate neutrality in business models. but on different time scales for scope 3 emissions.

Some scope 3 emissions of Hamburg businesses could reach climate neutrality after 2040. Scope 3 emissions targets could be set in a differentiated way, depending on goods and services and whether value chains originate in Germany, the EU and other OECD countries. Value chains originating in the EU should reach net zero GHG emissions by 2050 without offsets at the latest. Elsewhere, they should broadly follow science-based worldwide emission reduction scenarios consistent with limiting global warming to 1.5 degrees with at least 50% probability. This would require reaching net zero CO2 emissions in value chains while halving methane emissions by 2050.

  • The HCC could set intermediate emission reduction targets for 2030 for scope 1 and scope 2 emissions and provide guidance on intermediate scope 3 emissions targets for businesses.

  • The HCC may prepare investment guidance to avoid costs from delayed action. It could indicate the latest point of time when purchases of new fossil-fuel-using equipment should be avoided. For example, with an average useful life of cars of 15 years, purchases of new cars with internal combustion engines, if used in Hamburg for their entire useful life, should be avoided from 2025.

Meeting these recommendations would align climate action by the HCC and its members with recommendations from the High-level Expert Group of the United Nations (UN) on net-zero commitments of non-state entities (Box 1.3). The expert group provides ten science-based best practices recommendations for non-state entities' net-zero claims which Hamburg businesses should follow (United Nations' High-Level Expert Group, 2022[22]).

Understanding the sectoral composition of Hamburg's GHG emissions is essential to reach the climate neutrality objective. The Hamburg Statistics Office produces statistics for Scope 1 and Scope 2 energy-related CO2 emissions. Emissions in this section refer to 2019 to avoid the COVID-19 lockdown effects on emissions in 2020. Data on Scope 3 emissions are not available.

According to the Hamburg Statistics Office, total Scope 1 CO2 emissions decreased from 12.7 million tonnes in 1990 to 10.4 million tonnes in 2021 (Figure 1.2). Energy transformation and transport are the sectors generating the most emissions. Coal-fired electricity generation rose from 2013 to 2019, but fell with the closure of one of two remaining coal-fired heat and power plants in 2021. Emissions in energy transformation include close to 1 million tons of CO2 emissions from oil refining.

Hard coal accounted for approximately half of the energy transformation sector’s Scope 1 emissions in 2021 (Figure 1.3). Emissions from energy transformation therefore fall more in 2022. Even so, natural gas contributed around a third to electricity generation (Figure 1.3). Natural gas also is a major emissions source in the industrial sector, in the other business sectors, and in households, where it is mostly used for heating and cooling of buildings. Heating oil also contributes to emissions in these sectors. The relatively small reductions in emissions between 1990 and 2021 indicate that action to reduce emissions needs to accelerate sharply to reach climate neutrality by 2040. Natural gas use and mineral oil use will need to be phased out by 2040. A conceivable exception is process emissions in manufacturing from gas or oil use, which could be abated with CCS although hydrogen use could avoid CCS, as discussed in chapter 3. Mineral oil use in energy transformation mostly reflects oil refining. Lignite and mineral oil in energy use will also need to be phased out by 2040.

Around three-quarters of transport emissions come from road transport, followed by air transport and inland shipping. International shipping emissions are not included. Scope 1 transport emissions matter for businesses on account of road freight and passenger transport. Private households may account for most scope 1 emissions in passenger transport. To the extent travel from and to work generates these emissions, they also contribute to businesses’ scope 3 emissions.

Manufacturing activities account for most industrial scope 1 emissions, as mining activity is minor. Emissions-intensive manufacturing of basic materials is among the most difficult to decarbonise (OECD, 2023[7]). Using EU ETS data allows for a sectoral breakdown, albeit with the limitation that small emitting installations may not be included (OECD, 2023[7]). Most manufacturing emissions in Hamburg arise in oil refining, followed by the production of iron and steel, and then the manufacturing of aluminium (Figure 1.4, Box 1.4) (OECD, 2023[7]) Industrial emissions presented by Hamburg Statistics in Figure 1.2 are lower, because they include oil refining in energy transformation rather than in industry.

The Hamburg Statistics Office provides statistics that attribute emissions in energy transformation to energy end-use sectors by adding Scope 2 emissions to the Scope 1 emissions (“Verursacherbilanz”). Energy end-use sectors exclude activities engaged in energy transformation, notably the production of electricity and heat and oil refining. Indirect emissions from electricity generation are attributed following the average emissions in Germany. In 2021, Hamburg recorded 14.45 million tonnes of Scope 1 and 2 emissions in energy end-use sectors, 6.6 million tCO2 less than in 1990. Scope 2 emissions add substantially to emissions in industry and other business activities as well as in households (Figure 1.5). This reflects the high share of electricity and heat in the energy mix of these sectors (Figure 1.6) and the relatively high share of emission-intensive coal in German electricity and heat generation. By contrast, Scope 2 adds only marginally to transport emissions.

Germany-wide decarbonisation of electricity generation will reduce Scope 2 emissions, measured in this way, in Hamburg. As long as the energy mix is not fully decarbonised, Hamburg businesses can reduce their Scope 2 emissions by reducing energy use or by purchasing it from renewable sources. Businesses will not generally be able to choose a district heating provider. Climate-neutral district heating will require that heat generation from coal-fired power inside and outside Hamburg by the regional energy utility is phased out. The regional government, which owns the district heating provider, is committed to doing so by 2030.

A key challenge to reaching climate neutrality is the need to electrify most energy use while moving almost all electricity generation to renewables. According to the IEA, to reach net zero GHG emissions worldwide in 2050, electricity will need to represent 52% of the final energy consumption, a significant increase from the 20% in 2021. 88% of electricity generation will be from renewables (International Energy Agency, 2022[24]). In Europe, renewable generation is expected to increase by more than 380% to reach climate neutrality in 2050, compared to 2021 (International Energy Agency, 2022[24]). Germany aims to reach a share of renewables of 80% already in 2030. Without efforts to lower energy consumption, the needed expansion of renewable electricity production risks being at a scale that is difficult to manage. In a climate-neutral world, energy is therefore likely to be scarce. The energy intensity of GDP may need to fall by about two-thirds by 2050 worldwide (OECD, 2021[15]). In the EU, the RePowerEU plan sets an energy efficiency target of a 13% reduction in primary energy consumption (European Commission, 2023[25]). In addition to reducing costs, lowering energy demand also raises business resilience to energy supply shocks.

Some energy needs can be met from sustainable, zero-carbon sources without electrification. Biofuels can replace fossil fuels with relatively limited changes in equipment, such as in motor engines. Biofuels only eliminate emissions if sourced from the sustainable growth of biomass. However, the calls on bioenergy for industrial production alone are likely to exceed sustainable bioenergy supply (Material Economics, 2019[26]). Biomass growth also competes with essential land uses, notably for food production and biodiversity protection. Moreover, biomass supply is vulnerable to shocks, including from extreme climate events such as fires or drought.

“Green hydrogen”, produced from renewable electricity and hydrogen-derived products, such as synthetic fuels, may also serve decarbonisation instead of electricity. This applies especially when electrification of energy use is difficult, for example, because temperatures in production processes are very high. However, transforming renewable electricity into hydrogen implies substantial energy loss. Green hydrogen production may be concentrated in regions across the globe with the highest renewables potential and will be internationally tradable and therefore subject to shocks that can be transmitted internationally.

Hence, the limitations of bioenergy and hydrogen, including hydrogen-derived fuels, argue to prioritise them for uses in which electricity or other energy sources are not suitable or insufficient. Priority use is notably in heavy-duty transport (air as well as heavy-duty road freight and ship) as well as in manufacturing sectors which are difficult to decarbonise. In the longer term, biomass firing is a key source of net negative emissions if combined with carbon capture and storage (CCS) (Intergovernmental Panel on Climate Change, 2019[27]). Relying on hydrogen and biomass when not necessary may also weaken resilience, as these energy sources may be susceptible to shocks and high prices.

Further renewable energy sources beyond electricity include solar and geothermal energy to produce heat. Their contribution to meeting final energy demand is expected to be limited. Globally, to meet projected energy consumption for net zero emissions by 2050, hydrogen may represent 6%, biofuels 4%, and heat, including from geothermal sources, 2% of the total energy supply (International Energy Agency, 2022[28]).

Transport uses the most energy across sectors in Hamburg (Figure 1.7), with road transport accounting for the largest share (Figure 1.8). Energy-saving transport modes are therefore particularly important. Transport is also the sector that is least advanced in the electrification of energy use (Figure 1.9). In industry and other business sectors electricity accounts for approximately half of energy use.

The metals industry, including steel, copper and aluminium production, is the largest energy user in the manufacturing sector, followed by food production (Figure 1.10.). Most energy use has not been electrified in the production of metals, which adds to transformation challenges. Natural gas is the largest source of energy for producing metal and metal products. It is used in basic iron and steel production. It needs to be phased out to reach climate neutrality by 2040. Electricity is dominant in most of the other subsectors (Figure 1.11).

Lignite and mineral oils are still used in a few activities, especially in motor vehicle production and the manufacturing of chemical products. Its use is marginal, contributing little to energy use and emissions. Oil refining is not included in Hamburg’s industrial energy use statistics. However, it is the most energy-intensive manufacturing sector in manufacturing (OECD, 2023[7]). It also faces particular challenges because its output consists of fossil fuels which need to be phased out.

Hamburg is an economically successful, prosperous region by European and OECD standards. Its GDP per capita is the highest of the German regions, although growth has been weaker than in the most dynamic metropolitan areas in Germany as described in the OECD Hamburg Territorial Review (OECD, 2019[29]), Acting as soon as possible on the transition to climate neutrality can help position the Hamburg economy, making investment future-proof, avoiding unnecessary future costs, prepare for the challenges and benefit from the opportunities.

The Hamburg economy is broadly diversified with business services and manufacturing as major contributors to the generation of value-added (Figure 1.12). Transport and logistics, trade, and real estate sectors account for the largest service shares. Setting aside services dominated by the public sector, information and communication services and scientific and technical activities are also the most notable for their contribution to economic growth in 2021, as well as the manufacturing sector (Figure 1.13). By contrast, wholesale and retail trade, transport and logistics as well as financial services have shrunk or grown little. Manufacturing is also particularly energy and emission-intensive, as the industry share in energy consumption and Scope 1 and 2 emissions (mostly accounted for by manufacturing) exceeds the manufacturing share in value-added.

While transport and logistics have declined in the past, the region continues to strongly rely on logistics and trade, with the Hamburg port one of the major economic pillars (Box 1.5). The port is closely intertwined with manufacturing industries in Hamburg and beyond, notably those producing basic materials (including aluminium, copper and steel). For example, basic metals make up about a quarter of the general cargo import and export business of the port, while transport vehicles contribute 40%. Manufacturing and port activity irrigate other sectors. This can include activity through both links in supply chains, such as trading, technical or financial services, as well as demand effects from the income they generate. This is reinforced by high labour productivity in manufacturing.

As discussed in chapter 3, the city’s economy is well-placed to play a leading role in the decarbonisation of freight transport, which is difficult to decarbonise on a global scale, building on its strong rail infrastructure and its status as one of the 4 biggest ports in Europe. Moreover, shipping and rail freight are among the least energy-intensive freight modes. As this chapter has shown, transport is energy-intensive and cutting back on energy use is a key challenge in the transition to climate neutrality. Successful decarbonisation could therefore further add economic dynamism to the city. It is also well-placed in the decarbonisation of heavy-duty road transport as well as in the decarbonisation of key manufacturing industries. As discussed in Chapter 3, it can further play a major role as a hydrogen hub. It can draw on a broad range of forward-looking research and development and infrastructure deployment projects in these activities.

In many other service sectors, heating and cooling of buildings, electrifying equipment, and efforts to reduce energy use will dominate scope 1 emissions reductions. However, challenges to reduce Scope 3 emissions will differ. Some sectors process large volumes of emission-intensive goods and services. This applies to wholesale or retail trade or manufacturing. For example, Scope 3 emissions in the Hamburg-based copper production group Aurubis dwarf Scope 1 emissions (Chapter 2).

Construction activity will need to take on the task of making all buildings consistent with climate neutrality, which will bring a very large expansion of labour-intensive activity as well as new skill requirements. Business services as well as information and communication services will face opportunities, for example, from the use of digital technologies for the flexible use of intermittent renewables (Chapter 2) or the circular economy (Chapter 4).

OECD general equilibrium modelling suggests that sectoral value-added and employment shifts resulting from the transformation to reach climate neutrality are small in most sectors, across European Union countries, although there may be some loss of activity in some basic materials manufacturing industries. Impacts may be bigger in individual regions depending on their sectoral specialisation, but also their preparedness (OECD, 2021[15]).

Employment data allow a more detailed sectoral analysis than value-added data. Most sectors have expanded employment over the past 10 years. The wholesale and retail trade sector is the largest employer (Figure 1.15). Retail trade accounts for nearly 60% of the sector’s employment (Figure 1.16). The contribution of manufacturing to employment is relatively small, reflecting its high productivity.

Transport equipment manufacture, repair and installation of machinery and equipment, and manufacture of machinery and equipment are the three most important employers in manufacturing (Figure 1.17). Transport equipment mostly includes airplane production. Airplane production does not stand out in terms of local Scope 1 emissions and energy use, as shown above. It however faces major challenges to climate neutrality which result from emissions in flights. These are downstream Scope 3 emissions. Technologies for emission-free airplane fuels are not yet available. Beyond fuels, vapour trails and cloud formation of planes also contribute substantially to global warming. A near-term emission reduction option is the use of biofuels. In the longer-term substitution of air travel, especially short and medium-haul, may reduce demand.

Among the manufacturing sectors with relatively high Scope 1 emissions and high energy use, basic metals, oil refining and food production, each employ between 3 000 and 8 000 workers. However, only part of the food industry generates substantial Scope 1 emissions. These activities also face substantial challenges from Scope 3 emissions. These include the extraction of raw materials and downstream emissions from product use.

Warehousing and support activities account for about 50% of employment in transport and logistics (Figure 1.18). Businesses in support activities provide logistics services, services in loading and unloading of freight, support services for shipping and transport services across transport modes. These activities are strongly concerned by the transformations to climate neutrality and can benefit from ambitious action to make transport ready for climate neutrality (Chapter 3).

This section draws lessons from climate action in comparison cities, from their targets and action plans for the decarbonisation of the Hamburg economy. The three selected cities are Rotterdam, Seattle, and Stockholm (Table 1.3). Each provides features to be analysed for the benefit of the Hamburg economy.

Rotterdam has a similar economy to Hamburg, as Europe’s biggest port and transport hub, hosting industrial activity, notably in oil refining. It therefore may face comparable challenges in the transition. Seattle also hosts an international port and provides a very detailed decarbonisation plan for it. It also hosts industrial activity, notably in airplane construction. Rotterdam and Seattle propose climate neutrality objectives for 2050, and Stockholm is more ambitious with a climate neutrality objective for 2040. All three climate action plans cover Scope 1 emissions of buildings and transport, Seattle and Rotterdam also focus on the emissions of the port and industry. All three cities also include Scope 2 emissions from energy use, targeting emission-free energy provision. Rotterdam and Stockholm also target Scope 3 emissions from the consumption of goods and services. Seattle focuses mainly on Scope 3 emissions from the port.

To understand the emission composition of the selected cities, the emissions estimates (Box 1.6) of the Functional Urban Areas (FUAs) are compared to those of the Hamburg FUA. The FUA is composed of the city and its surrounding local units that are part of the city’s labour market (commuting zone) (Dijkstra, Poelman and Veneri, 2019[35]). FUAs are the most granular geographical breakdown available for which city GHG emission estimates are available.

Rotterdam and Hamburg have comparable estimated Scope 1 emissions, in amount and sectoral contributions (Figure 1.19), with similar reduction challenges. Seattle has lower emissions on account of power and heat generation. Stockholm’s estimated emissions are significantly lower, which may also be why their carbon neutrality goal is more ambitious. Stockholm has decarbonised power generation as well as heating in buildings, in large part owing to large-scale biomass firing. Biofuels also reduce emissions in road transport.

Hamburg's emissions per capita seem to be between Rotterdam’s and Seattle’s (Figure 1.20). Sectoral emissions per capita illustrate in which sectors bigger challenges remain. For example, the decarbonisation challenges of manufacturing in Rotterdam are bigger than in Hamburg. The transport sector of Hamburg has similar emissions per capita to those of Seattle, but they are lower in Stockholm and higher in Rotterdam. The emissions per capita arising from waste are similar across all four cities.

To decarbonise transport the three cities propose similar actions. They are:

  • Mobility hubs - the main aim is to aggregate connections between different transport modes, to improve their interoperability, with a focus on public transport, shared and e-mobility. The idea is to aggregate transport connections, so that mobility options carpools, electric cars, shared bicycles, and public transport are all connected to each other. Expected benefits are better transport and mobility access in low-income neighbourhoods as well as a reduction in car use.

  • Electrification of transport – which includes building charging points and rolling out shared electric mobility throughout the city. Seattle is mapping the optimal distribution of charging infrastructure to ensure equal distribution throughout the city. Stockholm has the goal of at least 4,000 public charging points. Stockholm also plans to introduce electric trucks for optimised inter-city deliveries. They will at the same time collect waste, thereby reducing traffic.

There are also actions which are particular to each city. For example, Rotterdam is placing a focus on creating a business leaders’ roundtable, including businesses with 110,000 employees altogether, to discuss how to improve mobility and share best practices. The city approached businesses to reach targeted agreements about sustainable commuting and business traffic with a minimum of 50% CO2 reduction by 2030.

Rotterdam and Stockholm are also focusing on finding emission-free solutions for the supply of building materials and making more efficient use of vehicles for delivery and collection. For Stockholm, this means developing an underground network and using sewage tunnels to transport building materials by boat instead of truck. To reduce the number of light trucks, Stockholm is also working with e-commerce distributors to create optimal routes to drop-off points, to reduce the number of trips. Rotterdam instead is consulting with a transport service provider to transition to emission-free inner-city heavy-duty transport. Optimised cargo logistics processes include decoupling points, where delivery trucks swap bodies moving containers to light vehicles or the use of plug-in hybrid trucks (City of Rotterdam, 2020[37]). Rotterdam is also working to reduce the number of transport movements of commercial waste vehicles.

To reduce building emissions the cities focus on fossil-fuel-free buildings, energy efficiency and public participation.

  • Fossil-fuel-free buildings - Rotterdam is working with neighbourhoods, property investors and housing associations for tailored plans to make all buildings natural gas free. Most neighbourhoods aim to be natural gas free by 2030. This includes connecting buildings to a district heating network as well as investing in the insulation of buildings, in climate adaptation and in opportunities for circularity. Seattle is also attempting to move buildings away from heating oil by supporting the conversion of oil-heated homes to electricity. Currently, there are recommendations to convert 18,000 homes from heating oil to electric heat pumps and help finance homes that are unable to switch on their own. Stockholm aims to fully phase out fossil oil and coal by connecting to heating plants with district heating and using biofuels. The city of Stockholm provides energy advice to property owners.

  • Energy efficiency in buildings - Rotterdam has a lot of programs to optimise performance such as the installation of green roofs, measures against heat stress, to start pilot energy cooperatives, insulate homes, and make installations and lighting more sustainable. There are plans for 1000 homes to be equipped with solar panels and expand electric cooking. Seattle aims to provide property owners with advice on energy efficiency. The Seattle City Lights program aims at energy savings through Energy Efficiency as a Service (EEaS). EEaS helps overcome split incentive barriers in commercial buildings, where there is little motivation for owners or investors to finance retrofits which benefit the tenants. Tenants pay for the provision of energy-saving investments. EEaS lets investors finance projects with predictable returns, owners generate a new revenue stream, and tenants occupy energy-efficient spaces.

  • Public participation - Rotterdam has set up a Climate Roundtable for the Built Environment and is setting up a digital platform to exchange knowledge and advice on the decarbonisation of buildings. Rotterdam is also designing a toolbox for real estate agents to educate and inform customers about opportunities for going natural gas-free and promoting sustainability. The city of Seattle intends to work with building owners through incentives and technical assistance to help them become voluntary early adopters and phase in performance requirements.

All three cities have some focus on consumption emissions, with specific focuses on food and waste. Stockholm also mentions actions to tackle aviation emissions.

  • Food - All three cities are looking for opportunities to reduce emissions from food consumption, mainly through the reduction of food waste. Rotterdam has made agreements with producers and other parties to avoid waste by providing meals to social restaurants. Rotterdam is also piloting a study to understand how the city can shift consumer preferences towards plant-based nutrition.

  • Circular economy and waste prevention – Rotterdam is focusing on the reduction of textile waste, hence has opened a clothes exchange, where 2nd hand clothes are traded. Rotterdam is also looking into developing a circular department store, allowing consumers to find sustainable brands in one place. Rotterdam is also researching opportunities for more and better recycling of textiles and developing a chemical recycling facility for local upgrading of discarded textiles. Seattle is focusing on building deconstruction while saving building materials. Stockholm is developing a digital system to make recycling operations more accessible to the public.

  • Aviation – Stockholm is running a city-wide communication campaign on the impact and alternatives of air travel. The city is also researching the most effective carbon offsets to mitigate the emissions from air travel.

The cities of Rotterdam and Stockholm also have separate climate actions to accelerate the uptake of clean energy (wind and sun) in the city and reduce reliance on fossil fuels.

  • Wind – The city of Rotterdam is working on accelerating four-wind energy projects and there is a consultation ongoing for the North Sea Program (2022-2026) with the goal of an additional 10GW of wind at sea by 2030. The important part is to connect wind electricity to the national platform. It could serve to meet regionally concentrated electricity demand for industrial purposes, including hydrogen production (see below). Stockholm plans on buying electricity from wind turbines through long-term contracts.

  • Solar – The city of Rotterdam has a pilot project to install photovoltaic panels on residential roofs through energy cooperatives, with the goal of 90 solar roofs by 2025. This includes knowledge sharing, networking, development and management of projects. For residential areas, the city plans to research and develop links between the generation, storage, and distribution of solar electricity. The project also aims to put solar panels on all suitable company and parking roofs. A subsidy scheme started in mid-2021 to enable entrepreneurs to benefit from a roof capacity assessment for solar panels. In Stockholm, estimates indicate that potential electricity produced with photovoltaic panels could cover more than 10% of the city’s needs. The aim is to increase solar production by 100% relative to 2018.

  • CCS – The city of Stockholm aims to introduce bioenergy use combined with carbon capture and storage (BECCS) to reach net negative emissions. In Stockholm, the combined heat and power plant used for district heating would be suitable for CCS. A trial is planned to be built at the plant.

The Port of Rotterdam is among the top 15 worldwide in terms of cargo throughput and containers shipped. The economic and cultural roots of the city are closely connected to the port (OECD, 2016[38]). In 2018. the port of Rotterdam contributed 6.2% of value added to the economy of the Netherlands (Port of Rotterdam, 2018[39]). The port and industry cluster provide direct and indirect employment for almost 400,000 people (Energieswitch, 2019[32]). The goal of the city of Rotterdam is to become the most sustainable port in the world. The Climate Roundtable of Port and Industry includes the authority of the Port of Rotterdam, energy companies, the municipality and provinces of Zuid-Holland, the nature and environmental federation of Zuid-Holland, companies that form the Port of Rotterdam industrial complex, and other government and knowledge institutions.

The Climate Roundtable of Port and Industry established phases and objectives in the decarbonisation of the port and industry. They concern efficiency measures, transitioning from fossil fuels to sustainable energy sources and creating economic and employment opportunities, putting Rotterdam in a strong competitive position.

The Climate Roundtable of Port and Industry have developed an investment agenda, which includes two main projects:

  • The Cluster Energy System (CES) identifies key infrastructure necessary for the transition, including hydrogen infrastructure, wind farms, and CCS infrastructure with multiple pipelines (Box 1.7).

  • The Data Safehouse is an exchange of information between major industrial companies and electricity distribution network operators to prepare for the electrification of industrial energy needs. The aim is to allow network operators to understand how much extra electricity is required to plan investment efficiently and meet the needs of companies in the switch to renewables.

The projects are also linked to an acceleration platform which aims to provide support in finding funding and removing barriers in legislation and regulations. The platform aims to accelerate the implementation of hydrogen, industrial electrification, industrial residual heating and circular processes projects.

The port also aims to produce renewable energy. According to The Climate Roundtable of Port and Industry, the additional sun potential is 130-150 MWp. The port has committed to installing solar panels on commercial roofs within the port area. The port also aims to build a floating solar park but this is currently postponed due to financial barriers.

The industrial processes in Rotterdam are to be electrified to replace natural gas. The Field Lab Industrial Electrification allows the industry to gain knowledge about potential electrification, test new technologies and make it ready for implementation. Furthermore, the heating from residual heat in industry, heat from geothermal energy, and other local heat sources are expected to provide heat to businesses in the region, Zuid-Holland.

The port of Rotterdam also has circular economy plans. The port aims to utilise residual flows, biomass, and captured CO2 in industrial processes. The industry in the port of Rotterdam will eventually be based on circular and renewable carbon materials, notably from biomass sustainable biomass and hydrogen. New factories and value chains organised in clusters will support the raw materials transition.

Labour market shortages are one of the biggest challenges faced by the port and industry, notably a shortage of technical personnel. Rotterdam aims to implement a training agenda to increase the required skills supply for the energy transition, coordinated by the Rotterdam Apprenticeship Agreement.

The port of Seattle has its own climate targets and plan. The port aims to:

  • By 2030, reduce Scope 1 and 2 emissions by 50% below 2005 and by 2050 to be carbon neutral or carbon negative.

  • By 2030, reduce Scope 3 emissions by 50% below 2007 and by 2050 to 80% below 2007 levels.

The action scenario identifies strategies to reduce emissions that are directly and indirectly controlled by the port.

To achieve immediate emission reduction in the boat fleet of the port, the initial plan is to switch to nonpetroleum-based fuels such as waste cooking oil and grease or other renewable feedstock. The current focus of the port is renewable diesel since it is more readily available than renewable gasoline. The goal is to shift to electric vehicles focusing first on light-duty vehicles while tracking developments in heavy-duty electric vehicles. The port will prepare for this transition by installing the required charging stations. At the same time, the port is eliminating under-utilised vehicles from the fleet and maximising use per vehicle.

To reduce waste the port aims to maximise the separation of common recyclables and organics, minimise solid waste generation and expand specialised recycling. The port will run waste audits, every three years, to assess proper waste disposal and develop site-specific reduction plants. The aim is also to identify items that are potentially recyclable but that are not accepted by the City’s recycling program, such as scrap metals, building materials, electronics and furniture and add customised recycled programs when feasible.

The port recognises that it has influence but no direct control of the emissions in maritime transport. This includes emissions from ships, harbour vessels, trains and other equipment, which account for 94% of the port’s Scope 2 and 3 emissions. The port is envisioning what the sector will look like in a carbon-neutral economy and preparing the necessary infrastructure to be ready when the transition occurs. The port is encouraging the stakeholders, the community, industry and government, to shift towards the carbon-neutral vision. The goal is to provide these stakeholders with guidance and influence decisions through partnerships, programs, and port facility lease terms. The port is willing to play a leadership role by advocating for new technologies and fuels by supporting pilot projects and adopting small-scale zero-emission technologies in Port-owned workboats and cargo-handling equipment. The Hamburg port also has developed a vision for climate neutrality, setting a target for reaching it in port operations by 2040, with a planned monitoring of emission reductions towards the target.

The port also encourages start-ups in port-related industries to partner with the port’s maritime innovation centre to achieve emission reduction in the maritime sector. It will also support workforce development and training to operate and maintain zero-emission maritime equipment.

The port is aiming to provide the infrastructure necessary for zero-emission vessels by 2030. This infrastructure includes new capacity for emission-free port manoeuvre boats, charging infrastructure, fuelling needs, and infrastructure for zero-emissions trucks. Until zero-emission vessels are developed there needs to be continuous improvement in vessel efficiency. The efficiency gains may occur through improved ship design and operational practices. The port will also support the adoption of zero-emissions cargo handling equipment by 2050, which involves replacing diesel-powered units. The port will also coordinate with cruise lines to evaluate carbon offset programs.

Other Scope 3 emissions the port is tackling are emissions commutes from port workers. 53% of port employees commute individually by car. To reduce the emissions generated, the port will encourage flexible work arrangements to reduce commuting days. It will also promote alternative modes of transport through subsidised vanpooling, bike sharing or organised carpooling.

Insights from the comparison cities yield recommendations for coordinating and facilitating climate actions in Hamburg. They are:

  • Business and public participation in decision-making. This can come in the form of roundtables for specific sectors. Experts in the sectors and topics are also part of the decision-making process. It may also take the form of online platforms, information campaigns and welcoming feedback from citizens. The involvement of citizens, business owners and local stakeholders lowers resistance to the transition. Such participation needs to be organised as quickly as possible, as it may lengthen the time to prepare decisions.

  • Long-term vision is essential. This ensures that long-term investments that businesses will undertake are in line with the climate neutrality targets. Rotterdam has done this through the development of an investment agenda for the port and industry. Seattle demonstrates their long-term vision with the emission-free infrastructure investments of the port.

  • Continuous tracking and evaluation of actions. Seattle is running multiple audits for the different climate actions the cities and ports are undertaking. This allows for a continuous reassessment and improvement of the ambition and climate action.

  • Reduction of Scope 2 and 3 emissions by major actors.

  • Avoid increasing inequalities within the city. Seattle is mapping the optimal distribution of electrical charging points to ensure that lower-income neighbourhoods are not left behind. Rotterdam is providing a subsidy scheme for the installation of solar panels which allows most citizens to participate.

Local climate policies not only contribute to achieving global, national and regional climate goals but can also enhance the well-being of residents, workers and firms, substantially, especially in cities, in a broad range of dimensions (Box 1.8). From the local business perspective, well-being gains, such as from reduced traffic congestion or cleaner air, influence worker and firm location decisions and therefore have the potential to make Hamburg more attractive and competitive to businesses and workers. Economic outcomes also improve with health – for example lower air pollution boosts productivity (Dechezleprêtre, Rivers and Stadler, 2019[42]). Air pollution reduces performance in tasks requiring high skill levels, such as the performance of investors on the New York Stock Exchange (Heyes, Neidell and Saberian, 2016[43]). Good accessibility of jobs and key facilities from homes, for example with on-demand mobility services, save travel time and make commutes less exhausting. A more convenient neighbourhood with such features would further attract skilled workers. Local climate policy can deliver these co-benefits.

These well-being benefits typically exceed the cost of local climate action. Several studies find that air quality co-benefits alone offset a large proportion of climate policy costs (Karlsson, Alfredsson and Westling, 2020[44]). For the East-Asia region, the co-benefits of climate change mitigation in terms of human health have been estimated to reach 6% of GDP, when also including the impact on climate adaptation. This exceeds the estimated cost of mitigation of 2% of GDP (Xie et al., 2018[45]). Many of the well-being benefits accrue locally and, unlike the climate benefits, immediately. They can therefore substantially improve the political economy of climate action, escaping the prisoner’s dilemma perspective, and be a powerful motivator for local and regional action, including by the business community.

Passenger transport is strongly related to congestion, air and noise pollution, and car accidents, especially in urban areas. The social cost of private car use in cities is estimated to be about 6-7 times higher than the cost borne by individual car owners and drivers. (van Dender, 2019[46]). The high share of external costs due to congestion further highlights the major benefits from reducing the volume of car use (Table 1.4). Compared to conventional vehicles, lightweight electric vehicles emit only 18-19% less PM2.5 from non-exhaust sources (OECD, 2020[47]), which means electrification alone cannot eliminate air pollution, in part reflecting pollution from wheel friction. Thus, decarbonisation of passenger transport by reducing individual car use has a high potential for creating co-benefits. It can be done making public transport more attractive; and by designing pedestrian- and cycle-friendly public spaces. As argued below, ride-sharing can also make a major contribution. Ride-sharing goes well beyond car-sharing: it refers to the use of cars by several passengers with different trip origins and destinations. As argued below, ride-sharing should replace individual car use, resulting in the abolition of day-to-day individual car use, as discussed further below.

Further benefits from reducing car use come from lower energy use, especially in the context of the likely more regional determination of electricity prices in the future, and lower indirect emissions. The transport sector, including transport and freight within Hamburg, is the largest energy consumer in Hamburg (Figure 1.7 above), and car use is likely to represent the largest share. Electric vehicles (EVs) are increasing demand for green electricity. Life-cycle emissions of EVs are also important. Therefore, decreasing the number of cars on the road is a robust approach to fundamentally decarbonise the transport sector. Lower energy demand is a key priority on the way to net-zero emissions.

Expanding public transport is a good way to reduce car dependency. Access of residents in the Hamburg metropolitan area to other residents in the area is less good than in some other cities (Figure 1.21). This may not reflect differences in public transport service quality, but, instead, the extent to which low-density rural areas are part of metropolitan travel to work areas. The Hamburg metropolitan region includes such low-density areas extensively. Low-density areas are typically less well served by public transport. Indeed, adding fixed-route buses and metro services at large enough volumes can be costly, especially in areas of lower population density, such as in the suburbs. Thus, harnessing the co-benefits from reduced individual car use requires a comprehensive policy package including housing policy, urban planning and a transport system that increases accessibility.

Metropolitan governance will allow the residents to benefit from public transport and housing that are coordinated throughout municipalities in the same travel-to work area, while improving accessibility of jobs and services, reducing air pollution and congestion as well as eliminating GHG emissions. A denser and more contiguous residential development would help reduce emissions and increase the satisfaction of residents with public transport. The experience of OECD countries offers lessons for metropolitan governance reforms (OECD, 2015[55]). Recommendations include establishing a regional planning association, adopting digital mobility solutions and integrating housing and transport planning, as argued in the OECD Territorial Review for the Hamburg Metropolitan Region (OECD, 2019[29]). They are complex processes, requiring political support, effective coordination, and reliable funding. The benefits may also take time to materialise. For example, the densification of neighbourhoods well-connected to jobs, services or public transport may take many years and may therefore not be sufficient to reach climate neutrality by 2040.

As an innovative option, on-demand shared mobility services supported by digital technology could also help meet urban mobility needs in a way that eliminates emissions while reducing energy use and harnessing the co-benefits discussed above. Ride-sharing services can be operated on a single integrated platform, where users submit requests and a digital dispatcher matches vehicles to demands on a real-time basis. Considering users’ demands and traffic conditions, the system assigns vehicles and generates the optimal routes to destination adhering to pre-set time constraints for all users.

On-demand ride-sharing services available at the doorstep or the next street corner would improve the connectivity of residents with each other and accessibility of jobs or services, especially for low-income households and households in low-density suburban areas, who are often less well connected to public transport. Ideally, all individual car rides in an entire metropolitan area are replaced by shared modes to decrease CO2 and other negative externalities such as car accidents, air pollution and noise pollution. The advantages of ride-sharing can be maximised when the vehicles are electrified because electric vehicles (EVs) emit less air and noise pollution from engines. Also, the operating cost of electric vehicles is lower than of conventional vehicles, reflecting less repair and higher energy efficiency, a key benefit with intensive use. Users may also benefit more from the development of technology (e.g., battery improvement) as shared vehicles are replaced more often than individual vehicles.

Digital-based ride-sharing can lower CO2 emissions sharply. In the full replacement scenario where buses and private cars are fully displaced, as modelled for Dublin for example (Box 1.9), vehicle kilometres and CO2 emissions are substantially reduced, even if internal combustion engines were kept, although the amount of change depends on the size and density of an area, infrastructure and land use (Tennøy and Hagen, 2020[56]). In Ireland’s Greater Dublin Area, for example, CO2 emission can decrease by 42% to baseline if shared modes replace all individual fleets (ITF, 2018[57]). Of course, electrification does away with Scope 1 emissions. However, the estimated emission reductions are still informative on the substantial reduction of energy use. In the case of the Lisbon Metropolitan Area, the estimated impact was more dramatic at 62% (ITF, 2015[58]).

The major co-benefit of mobility-sharing services is decreased road congestion and air pollution. In the Lyon metropolitan area, the lack of public transport and road capacity from the outer part towards the centre to host private car flows are the major sources of traffic jams. Ride-sharing would relieve this issue and increase user satisfaction by decreasing the total number of vehicles on the road. Shared mobility services including car ride-sharing are expected to reduce congestion by 48% according to the Lyon study. In Dublin, the adoption of shared modes in addition to the existing rail and light-rail transit (LRT) can meet local mobility needs with 98% fewer private vehicles in that area. The introduction of ride-sharing services such as Shared Taxis and Taxi-Buses to Dublin is also expected to reduce the total local travel by 38% and traffic jams by 37% (ITF, 2018[57]).

The adoption of ride-sharing services also has the potential to significantly open up public spaces currently occupied by privately owned cars, which tend to remain parked for extended periods. In a simulated scenario for Lisbon, the ITF projected that Shared Taxi and minibus services could lead to a remarkable 95% reduction in the total area allocated for parking (ITF, 2015[58]).

Survey results suggest that 20% of car drivers would be willing to switch to shared rides in Dublin. This share is substantially higher if public awareness is increased with information on how cheaper ride-sharing compares to current private car use. Survey results for Lyon suggest that most citizens are willing to use shared modes.

From the perspective of operators, ride-sharing is also low-cost. For Dublin, the cost of shared minibus services would be less than the price of a public transport ticket, yet would not need to be subsidised. On-demand ride-sharing could be provided at about half the price of public transport offered today. If implemented at a large scale to reduce waiting times, shared mobility would be more desirable for citizens (ITF, 2018[57]). Shared rides could substitute inefficient bus lines, in addition to private car use, and provide feeder service to rail.

Road use charges will be necessary to replace fossil fuel taxes when fossil-fuel vehicles are phased out, both to replace revenue streams as well as to price negative externalities related to vehicle use such as congestion, accidents, and noise. Road use charges that are time and place-contingent can price externalities more efficiently, especially in urban areas, where external costs are much higher than typical fuel tax rates today (OECD/ITF, 2019[59]).

Since electric vehicles have low operating costs, the diffusion of EVs could intensify car use in cities, aggravating congestion. Automated driving adds to these risks, as it will reduce the opportunity cost of the time spent in the car. Such improvements would lower the cost of private mobility, raising the demand for it, including by encouraging urban sprawl. Large-scale introduction of ride-sharing would also bring efficiency gains and would therefore also need to be accompanied by road charging. Without road use charges, the more efficient mobility services provided by ride-sharing could result in residents increasing mobility demand, for example, by living further away from their workplace, offsetting the effects of ride-sharing on congestion and air pollution.

Road-use charging can include congestion charging (Box 1.10). Policy makers need to decide which roads should be covered. Stockholm has been operating the congestion tax since 2007 to improve transport in central Stockholm. A vehicle is charged every time it passes the charging points, between 6:00 am and 6:29 pm during weekdays. The price depends on the time of day and season, ranging from SEK 11 to SEK 45 each time, with a maximum of SEK 135 per day and vehicle (Transport Styrelsen, 2022[60]). Although public acceptance was less than 40% in 2005, it rose to more than 50% after a trial period in 2006 and to 65% in 2007 after the official adoption. The level of public support further increased to approximately 70% in 2011. Thanks to the charges, traffic fell by 16% in the inner city and by more than 5% outside the cordon, accompanied by a substantial decrease in travel time. In terms of environmental effects, a 10 to 15% reduction in carbon dioxide (CO2) emissions, a 10 to 14% reduction in air pollutants, and an 8.5% reduction in nitrogen oxides (NOx) were observed in the inner city. CO2 emissions in the region of Stockholm decreased by 2 to 3% (Transport Styrelsen, 2022[60]).

Other metropolitan areas of the OECD countries, such as London, Milan and Singapore, have also adopted congestion charges and successfully reduced congestion, travel time, and air pollution (OECD, 2010[61]). In the case of Milan and Singapore, this drop has been linked to vehicle emissions (OECD, 2019[62]). Lessons from the London Congestion Charge show that attitudes change in favour of policies to reduce car demand after their successful introduction as the benefits of less car use materialise (Downing and Ballantyne, 2007[63]).

There are several limitations attached to the development of user charges including the legal ability of subnational governments to create and determine the level of such fees, as well as the capacity and willingness to pay of users (OECD, 2019[62]). Those who can afford all the costs would continue using private vehicles anyway. In other words, such a policy can have negative distributional effects when individuals being taxed do not have alternative means of transport to turn to. Therefore, they need to be accompanied by policies that allow substituting for private car use. public and shared transport systems need to be sufficiently accessible to offset rising inequality as a consequence of a price-based instrument. High-quality ride-sharing could contribute to making more shared transport available.


[52] Basner, M. et al. (2014), “Auditory and non-auditory effects of noise on health”, The Lancet, Vol. 383/9925, pp. 1325-1332, https://doi.org/10.1016/s0140-6736(13)61613-x.

[48] Bishop, K., J. Ketcham and N. Kuminoff (2018), Hazed and Confused: The Effect of Air Pollution on Dementia, National Bureau of Economic Research, Cambridge, MA, https://doi.org/10.3386/w24970.

[18] Buck, H. et al. (2023), “Why residual emissions matter right now”, Nature Climate Change, https://doi.org/10.1038/s41558-022-01592-2.

[8] Chapman, R. (2019), Managing the transition to a climate-neutral economy in cities and regions.

[50] Chapman, R. et al. (2018), “A Cost Benefit Analysis of an Active Travel Intervention with Health and Carbon Emission Reduction Benefits”, International Journal of Environmental Research and Public Health, Vol. 15/5, p. 962, https://doi.org/10.3390/ijerph15050962.

[16] Chen, Z. et al. (2018), “Consumption-based greenhouse gas emissions accounting with capital stock change highlights dynamics of fast-developing countries”, Nature Communications, Vol. 9/1, https://doi.org/10.1038/s41467-018-05905-y.

[37] City of Rotterdam (2020), Zero Emission City Logistics Rotterdam.

[31] City of Seattle (2018), Seattle Climate Action.

[68] Climate Science (2022), Emissions by End-Use: What Activities Create the Most Emissions?, https://climatescience.org/advanced-emissions-by-product.

[6] Council of Economic Advisers (2014), The cost of delaying action to stem climate change.

[42] Dechezleprêtre, A., N. Rivers and B. Stadler (2019), “The economic cost of air pollution: Evidence from Europe”, OECD Economics Department Working Papers, No. 1584, OECD Publishing, Paris, https://doi.org/10.1787/56119490-en.

[35] Dijkstra, L., H. Poelman and P. Veneri (2019), “The EU-OECD definition of a functional urban area”, OECD Regional Development Working Papers, No. 2019/11, OECD Publishing, Paris, https://doi.org/10.1787/d58cb34d-en.

[63] Downing, P. and J. Ballantyne (2007), Tipping Point or Turning Point? Social Marketing and Climate Change, https://www.ipsos.com/sites/default/files/publication/1970-01/sri_tipping_point_or_turning_point_climate_change.pdf (accessed on 12 October 2023).

[51] EEA (2020), Environmental noise in Europe 2020, Publications Office of the European Union, Luxembourg, https://doi.org/10.2800/686249.

[32] Energieswitch (2019), Rotterdam Climate Agreement.

[69] Energy Information Administration (2022), Energy and the environment explained.

[67] European Commision (2021), European Emissions Trading System (ETS) – Calculations on the regional employment impact of ETS installations.

[25] European Commission (2023), Energy efficiency targets.

[36] European Commission (2022), Emissions Database for Global Atmospheric Research (EDGAR).

[12] European Commission (2022), Fit for 55 - Aviation and the EU ETS, https://climate.ec.europa.eu/eu-action/aviation-and-eu-ets_en.

[21] European Commission (2021), Aviation and the EU ETS.

[3] European Commission (2018), A Clean Planet for all. A European long-term strategic vision for a prosperous, modern, competitive and climate neutral economy.

[11] Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection of Germany (2016), Climate Action Plan 2050, https://www.bmuv.de/fileadmin/Daten_BMU/Pools/Broschueren/klimaschutzplan_2050_en_bf.pdf.

[54] Frontier Economics (2017), Affordable Warmth, Clean Growth: Action Plan for a comprehensive Buildings Energy Infrastructure Programme, https://www.aucklandcouncil.govt.nz/plans-projects-policies-reports-bylaws/our-plans-strategies/unitary-plan/history-unitary-plan/documentssection32reportproposedaup/appendix-3-8-5.pdf.

[20] German Presidency of the Council of the European Union (2020), EU2020.de.

[66] Glenk, K. et al. (2021), “The opportunity cost of delaying climate action: Peatland restoration and resilience to climate change”, Global Environmental Change, Vol. 70, p. 102323, https://doi.org/10.1016/j.gloenvcha.2021.102323.

[53] Grimes, A. et al. (2012), Cost Benefit Analysis of the Warm Up New Zealand: Heat Smart Programme, https://www.aucklandcouncil.govt.nz/plans-projects-policies-reports-bylaws/our-plans-strategies/unitary-plan/history-unitary-plan/documentssection32reportproposedaup/appendix-3-8-5.pdf.

[9] Hamburg Chamber of Commerce (2022), .

[30] Hamburg Chamber of Commerce (2010), Sector Profiles: Commercial Transport in Hamburg.

[72] Hamburg Ministry for Urban Development and Environment (2019), First revision of the Hamburg Climate Plan, https://www.hamburg.de/contentblob/13899086/749a6e50662c96eee81d370f1b0cb631/data/d-first-revision-hamburg-climate-plan.pdf.

[23] Hamburg Statistics Office (2022), Energiebilanz und CO2-Bilanzen für Hamburg, https://www.statistik-nord.de/zahlen-fakten/umwelt-energie/energie/dokumentenansicht/product/3381/energie-und-co2-bilanzen-fuer-hamburg-361?cHash=4201529a752424c94a05eb3c4ae751ea.

[10] Hamburger Senat (2022), Eckpunktepapier für die zweite Fortschreibung des Hamburger Klimaplans, https://www.hamburg.de/contentblob/16763680/bdac8f8d932cbd784b9256426fc5b11b/data/d-eckpunktepapier2022.pdf.

[49] Heissel, J., C. Persico and D. Simon (2019), Does Pollution Drive Achievement? The Effect of Traffic Pollution on Academic Performance, National Bureau of Economic Research, Cambridge, MA, https://doi.org/10.3386/w25489.

[43] Heyes, A., M. Neidell and S. Saberian (2016), The Effect of Air Pollution on Investor Behavior: Evidence from the S&P 500, National Bureau of Economic Research, Cambridge, MA, https://doi.org/10.3386/w22753.

[40] H-vision (2017), Numbers.

[13] IEA (2022), CO2 avoidance and use in raw material industries, https://www.iea.org/policies/13194-co2-avoidance-and-use-in-raw-material-industries.

[27] Intergovernmental Panel on Climate Change (2019), Climate Change and Land An IPCC Special Report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems.Summary for Policymakers., https://www.ipcc.ch/site/assets/uploads/2019/08/Edited-SPM_Approved_Microsite_FINAL.pdf (accessed on 21 October 2019).

[1] Intergovernmental Panel on Climate Change (2018), Global Warming of 1.5 Degrees Celsius, Summary for policy makers, Intergovernmental Panel on Climate Change Working Groups I, II, III, Word Metereological Organisation, United Nations Environment Programme, http://report.ipcc.ch/sr15/pdf/sr15_spm_final.pdf.

[28] International Energy Agency (2022), Energy Efficiency.

[24] International Energy Agency (2022), World Energy Outlook 2022.

[19] International Maritime Organization (2020), Fourth Greenhouse Gas Study 2020.

[57] ITF (2018), “Shared Mobility Simulations for Dublin”, International Transport Forum Policy Papers, No. 58, OECD Publishing, Paris, https://doi.org/10.1787/e7b26d59-en.

[58] ITF (2015), “Urban Mobility System Upgrade: How shared self-driving cars could change city traffic”, International Transport Forum Policy Papers, No. 6, OECD Publishing, Paris, https://doi.org/10.1787/5jlwvzdk29g5-en.

[44] Karlsson, M., E. Alfredsson and N. Westling (2020), “Climate policy co-benefits: a review”, Climate Policy, Vol. 20/3, pp. 292-316, https://doi.org/10.1080/14693062.2020.1724070.

[26] Material Economics (2019), Industrial Transformation 2050 - Pathways to Net-Zero Emissions from EU Heavy Industry, University of Cambridge Institute for Sustainability Leadership (CISL), https://materialeconomics.com/publications/industrial-transformation-2050.

[70] OECD (2023), OECD interviews with local stakeholders.

[7] OECD (2023), Regional Industrial Transitions to Climate Neutrality, OECD Regional Development Studies, OECD Publishing, Paris, https://doi.org/10.1787/35247cc7-en.

[71] OECD (2021), Germany country note to the OECD Regional Outlook 2021 - Progress in the net zero transition, https://www.oecd.org/regional/RO2021%20Germany.pdf.

[15] OECD (2021), OECD Regional Outlook 2021: Addressing COVID-19 and Moving to Net Zero Greenhouse Gas Emissions, OECD Publishing, Paris, https://doi.org/10.1787/17017efe-en.

[47] OECD (2020), Non-exhaust Particulate Emissions from Road Transport: An Ignored Environmental Policy Challenge, OECD Publishing, Paris, https://doi.org/10.1787/4a4dc6ca-en.

[62] OECD (2019), “Financing climate objectives in cities and regions to deliver sustainable and inclusive growth”, OECD Environment Policy Papers, No. 17, OECD Publishing, Paris, https://doi.org/10.1787/ee3ce00b-en.

[29] OECD (2019), OECD Territorial Reviews: Hamburg Metropolitan Region, Germany, OECD Territorial Reviews, OECD Publishing, Paris, https://doi.org/10.1787/29afa27f-en.

[4] OECD (2017), Investing in Climate, Investing in Growth, OECD Publishing, Paris, https://doi.org/10.1787/9789264273528-en.

[38] OECD (2016), OECD Territorial Reviews: The Metropolitan Region of Rotterdam-The Hague, Netherlands, OECD Territorial Reviews, OECD Publishing, Paris, https://doi.org/10.1787/9789264249387-en.

[55] OECD (2015), Governing the City, OECD Publishing, Paris, https://doi.org/10.1787/9789264226500-en.

[61] OECD (2010), Cities and Climate Change, OECD Publishing, Paris, https://doi.org/10.1787/9789264091375-en.

[59] OECD/ITF (2019), Tax Revenue Implications of Decarbonising Road Transport: Scenarios for Slovenia, OECD Publishing, Paris, https://doi.org/10.1787/87b39a2f-en.

[73] Office, H. (1990), Energiebilanz und CO2-Bilanzen für Hamburg, https://www.statistik-nord.de/zahlen-fakten/umwelt-energie/energie/dokumentenansicht/product/3381/energie-und-co2-bilanzen-fuer-hamburg-361?cHash=4201529a752424c94a05eb3c4ae751ea.

[41] Port of Rotterdam (2021), Six infrastructure projects central in first CES Rotterdam-Moerdijk.

[39] Port of Rotterdam (2018), The Rotterdam effect: economic significance of the port is twice as high as previously calculated.

[34] Port of Seattle (2021), Charting the Course to Zero.

[5] Sanderson, B. and B. O’Neill (2020), “Assessing the costs of historical inaction on climate change”, Scientific Reports, Vol. 10/1, https://doi.org/10.1038/s41598-020-66275-4.

[33] Stockholms Stad (2020), Climate Action Plan 2020-2023.

[56] Tennøy, A. and O. Hagen (2020), “Reallocation of Road and Street Space in Oslo: Measures for Zero Growth in Urban Traffic”, International Transport Forum Discussion Papers, No. 2020/14, OECD Publishing, Paris, https://doi.org/10.1787/6d7e9f43-en.

[64] Transport for London (2023), Congestion Charge marks 20 years of keeping London moving sustainably, https://tfl.gov.uk/info-for/media/press-releases/2023/february/congestion-charge-marks-20-years-of-keeping-london-moving-sustainably (accessed on 12 October 2023).

[60] Transport Styrelsen (2022), Congestion tax in Stockholm: Hours and amounts in Stockholm, https://www.transportstyrelsen.se/en/road/road-tolls/Congestion-taxes-in-Stockholm-and-Goteborg/congestion-tax-in-stockholm/hours-and-amounts-in-stockholm/ (accessed on 11 October 2023).

[65] U.S. Department of Transportation (2021), Lessons Learned From International Experience in Congestion Pricing, https://ops.fhwa.dot.gov/publications/fhwahop08047/02summ.htm (accessed on 12 October 2023).

[2] UK Committee on Climate Change (2019), Net Zero - The UK’s contribution to stopping global warming - Committee on Climate Change, https://www.theccc.org.uk/publication/net-zero-the-uks-contribution-to-stopping-global-warming/ (accessed on 23 October 2019).

[22] United Nations’ High-Level Expert Group (2022), Integrity Matters: Net Zero Commitments by Businesses, Financial Institutions, Cities and Regions.

[46] van Dender, K. (2019), “Taxing vehicles, fuels, and road use: Opportunities for improving transport tax practice”, OECD Taxation Working Papers, No. 44, OECD Publishing, Paris, https://doi.org/10.1787/e7f1d771-en.

[17] Wiedmann, T. et al. (2020), “Three‐scope carbon emission inventories of global cities”, Journal of Industrial Ecology, Vol. 25/3, pp. 735-750, https://doi.org/10.1111/jiec.13063.

[14] World Resource Institute, C40 Cities Climate Leadership Group and ICLEI – Local Governments for Sustainability USA (2021), “Global Protocol for Community-Scale Greenhouse Gas Emission Inventories: An Accounting and Reporting Standard for Cities”, World Resources Institute..

[45] Xie, Y. et al. (2018), “Co-benefits of climate mitigation on air quality and human health in Asian countries”, Environment International, Vol. 119, pp. 309-318, https://doi.org/10.1016/j.envint.2018.07.008.

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