Climate pioneership and leadership in structurally disadvantaged maritime port cities

ABSTRACT Innovative climate governance in small-to-medium-sized structurally disadvantaged cities (SDCs) are assessed. Considering their deeply ingrained severe economic and social problems it would be reasonable to assume that SDCs act primarily as climate laggards or at best as followers. However, novel empirical findings show that SDCs are capable of acting as climate pioneers. Different types and styles of climate leadership and pioneership and how they operate within multi-level and polycentric governance structures are identified and assessed. SDCs seem relatively readily willing to adopt transformational climate pioneership styles to create ‘green’ jobs, for example, in the offshore wind energy sector and with the aim of improving their poor external image. However, in order to sustain transformational climate pioneership they often have to rely on support from ‘higher’ levels of governance. For SDCs, there is a tension between learning from each other’s best practice and fierce economic competition in climate innovation.


Introduction
International relations (IR) and comparative politics (CP) scholars initially dominated the research on climate leaders and pioneers, focusing mainly on climate governance at the international, supranational and state level (e.g. Gupta and Grubb 2000). At first, scholars paid little attention to climate leaders and pioneers at sub-state level (e.g. regional, local and city levels) although there are exceptions, especially in the local governance literature (e.g. Betsill 2005, While et al. 2010). Over time, the importance of local climate governance increased to such a degree that Jänicke (2014, p. 43) has argued that 'the local level is a late mover in the process of climate policy, but has become the most dynamic driver of technical change towards a low-carbon energy system'.
The importance of local climate governance has increased for at least three reasons. First, IR and CP scholars discovered the significance of cities for global climate governance when international climate negotiations threatened to end in political stalemate. Secondly, cities are both major sources of greenhouse gas emissions (GHGE) and laboratories for experimentation with innovative learning-by-doing climate governance measures, some of which could possibly be up-scaled from the local level to 'higher' governance levels (e.g. Bulkeley et al. 2015, Kemmerzell 2017, Eckersley 2018, Kern 2019,this volume); thirdly, there is the issue of state 'hollowing out' where states have lost power upwards (to the international and/or supranational level), sideways (to business and societal actors) and downwards (to the subnational level) (e.g. Strange 1998). Social scientists have tried to capture the purported move from top-down climate government towards bottom-up climate governance analytically with the help of multilevel governance (MLG) concepts (e.g. Schreurs andTiberghien 2007, Wurzel et al. 2017) and polycentric governance approaches (e.g. Ostrom 2009, Morrison et al. 2017, Jordan et al. 2018, Singleton 2018 in which non-state and subnational actors play a prominent role. Urban politics scholars especially have argued that environmental governance is being rescaled around local and regional state structures in response to wider political and economic restructurings in liberal market economies (While et al. 2010). However, the nation-state level continues to play an important role for many climate governance initiatives by structurally disadvantaged cities (SDCs), which are not unitary actors. As we explain below, local level societal climate alliances play an important role for the ability of SDCs to adopt innovative climate governance measures Although there is growing interest in local climate governance, much of the literature has focused on relatively affluent and/or large cities that have acted as climate leaders or pioneers (e.g. Jonas et al. 2011, Bulkeley et al. 2015 and their national and transnational city networks (e.g. Kern and Bulkeley 2009). It has paid little attention to innovative local climate governance by less affluent small-to-medium-sized cities such as SDCs which suffer from serious economic resource constraints (for exceptions see Bulkeley et al. 2015, Jonas et al. 2017, Eckersley 2018. Here, we focus on Bremerhaven (Germany) and Hull 1 (UK) as case study cities because both classify as SDCs faced with similar economic, social and geographic challenges. Moreover, Bremerhaven and Hull are maritime port cities that have perceived climate change as both a threat (flooding due to sea water level rise) and an opportunity (offshore wind energy jobs). Both Bremerhaven and, to a lesser degree, Hull have experimented with innovative local climate governance measures. They have done so while acting primarily as what Liefferink and Wurzel (2017) define as pioneers. Wurzel (2017, see also Wurzel et al. 2017) have argued that leaders actively try to attract followers while this is not normally the case for pioneers. Considering their acute resource constraints and other structural disadvantages, it seems reasonable to assume that SDCs act primarily as climate laggards or at best as followers. However, based on our novel empirical findings, we argue that this is not necessarily the case. We show that SDCs are capable of acting as climate pioneers and, to a lesser degree, leaders. This creates a research puzzle, which we try to explain by answering the following main research question: How and why do SDCs act as climate pioneers or leaders?
We proceed as follows. In the next section, we define SDCs before briefly reviewing the urban climate governance literature while linking it to the analytical concept of leaders and pioneers put forward by Liefferink and Wurzel (2017). We then assess Bremerhaven and Hull's main innovative local climate governance activities. The penultimate section uses MLG and polycentric governance concepts to analyse the empirical findings from our two cities. The concluding section reassesses our conceptual framework and the main empirical findings while offering general conclusions about small-to-medium-sized SDCs.

Small-to-medium-sized structurally disadvantaged cities
For our definition of SDCs, we draw on Jonas et al. (2017) who have defined structurally disadvantaged maritime port cities as suffering from: geographical remoteness; long-term decline of industries (e.g. for maritime port cities fishing and shipbuilding); disused industrial assets and infrastructure (e.g. port facilities); high unemployment, low/underutilised skills base and declining populations; weak economic governance structures (including shrinking tax bases and high susceptibility to austerity measures); and, poor external image. Both Bremerhaven and Hull share these characteristics.
Our concept of SDCs resembles theories of structurally disadvantaged communities that have assessed minority communities in American inner cities, which exhibit serious social pathologies such as crime and public disorder (Kane 2005). Building on Wilson's (1987) seminal book, The Truly Disadvantaged, our concept seeks to capture the social and institutional structures (race and class) that have resulted in such communities becoming economically and socially marginalised. By way of contrast, we use the term SDCs in a more spatially and socially encompassing fashion to refer to small-to-medium-sized cities that are grappling with a range of structural problems. In other words, our focus is not on a particular social subgroup within the city but rather a collective of small-to-medium-sized cities that exhibit industrial decline, population loss, social problems, geographical peripherality and negative external images.
There is no hard and fast definition for what constitutes a medium-sized city. Le Galés (2002, p.5) has defined medium-sized cities as having a population of between 150,000 and 200,000 inhabitants. However, Le Galés (2002, p.32) also cites Kaelble (1988, p.62) who has pointed out that about one-third of Europe's population has lived in '[t]he mediumsized town of between 20,000 and 100,000 inhabitants [which has] played a more significant and more enduring role in the twentieth century than elsewhere'. Small-to-medium-sized cities cover free-standing urban centres having a population between 100,000 and 500,000; these are autonomous or separate local political jurisdictions governed by an elected city council or magistrate and led by a locally appointed or elected mayor; usually they are second or third tier urban centres within their host national economy/state. We have adopted the term small-to-medium-sized city to take into account that Bremerhaven had a population of about 112,000 while Hull consisted of approximately 258,000 inhabitants in 2016. The city of Bremerhaven together with the city of Bremen forms the state (Land) Bremen while Hull belongs to the Humber region; they have populations of about 672,000 and 921,000, respectively.
For many years, Bremerhaven has been among those German municipalities suffering the most severe economic problems (Wegweiser Kommune 2016). Röhl and Schröder (2017) even concluded that Bremerhaven is the poorest German city in terms of purchasing power. In 2005, Bremerhaven suffered from over 25% unemployment; in 2016, it was still 14.6%, more than twice the German national average (Statistisches Landesamt Bremen 2017). Bremerhaven eventually reversed decades of population decline in the early 1990s. In 1968, Bremerhaven's population peaked at about 149,000 before bottoming out at about 108,000 in 2011. By 2016, Bremerhaven's population had grown again to about 116,000, largely due to international immigration (Statistisches Landesamt Bremen 2017). Although Bremerhaven qualifies as a SDC, it nevertheless functions as a regional center for the labour market. In 2015, commuters constituted 47.3% of regular employees in Bremerhaven (Bertelsmann Stiftung 2017). Commuters who work in Bremerhaven but are residents in Lower Saxony (Land Niedersachsen), which surrounds the cities of Bremerhaven and Bremen, do not pay taxes in the Land Bremen.
Hull's population declined for decades after peaking at around 302,000 in 1931, falling to below 244,000 in 2001. The 2011 census found the decline had moderately reversed, largely due to international immigration (Migration Observatory 2014). However, compared to 2016 8% fewer migrants arrived in Hull in 2017(Migration Yorkshire 2018. This decline was largely due to the outcome of the UK's 2016 Brexit referendum. Hull's citizenry suffers from inter-generational unemployment, lack of skills development and social exclusion. In 2016, the city's unemployment rate was around 7.4% compared to 4.6% UK-wide, which constituted a significant improvement compared to 13.5% (7% national average) in 2015 (Hull Data Observatory 2017) 2 . A 2014 study of 64 UK cities, which compared indicators such as earnings, job seekers allowance and employment, ranked Hull amongst the most problematic cities (Centre for Cities 2014).

Cities and climate pioneership and leadership
'Cities lie at the heart of the challenge of addressing climate change' (Bulkeley et al. 2015, p.5) because they produce large amounts of GHGE and can act as laboratories for experimentation with innovative climate change measures. In the 1990s, a limited number of relatively large and/or prosperous cities (acting as leaders or pioneers that formed national and/or transnational networks) largely drove innovative urban climate governance (Kern andBulkeley 2009, Kern 2019,this volume). Largely ignoring SDCs, early urban climate governance studies focused mainly on leading cities and their best practices, core indicators and success factors, while emphasising the increasing relevance of local climate governance for urban 'green' economic development. Liefferink and Wurzel (2017) have argued that while leaders usually actively seek to attract followers, this is not normally the case for pioneers. They furthermore distinguished between four types of leadership/pioneershipstructural, entrepreneurial, cognitive, and exemplaryand two styles of leadership/pioneershiptransactional and transformational (Wurzel  1962, 1999, 2006, 2016 1953, 2007, 2013 Sources et al. 2017). However, their leadership/pioneership concept focused only on states while largely ignoring the subnational level. We apply Liefferink and Wurzel's (2017) analytical environmental leader and pioneer concepts to cities while focusing on SDCs.
In IR and CP, structural leadership/pioneership is associated primarily with military and economic power. While military power does not play a significant role for tackling climate change, economic power capabilities are crucial at any governance level including the local. In contrast to small-tomedium-sized cities (e.g. Bremerhaven and Hull), large cities (e.g. Berlin and London) have considerable economic power and thus structural leadership/pioneership capabilities (see Kern 2019, Jänicke and Wurzel 2019,both this volume). However, as Burns (1978, p. 19) has pointed out, '[a]ll leaders are actual or potential power holders, but not all power holders are leaders'. Cities' formal institutional powers can be interpreted as representing structural power resources. For example, city states (Stadtstaaten) such as Bremen, which encompasses the cities of Bremerhaven and Bremen, have significant powers under the German federal constitution. Structural leadership/pioneership activities may also include economic actions aimed at improving cities' positions in urban hierarchies or vis-à-vis cities with similar 'green' economy ambitions.
Entrepreneurial leadership/pioneership involves the use of diplomatic and negotiating skills with a view to brokering integrative bargains and agreements. Entrepreneurial leadership also includes networking between actors, sectors and governance levels. As explained below, for an emerging new industrial sector like the offshore wind industry, entrepreneurial leadership in the form of networking is of central importance. MLG concepts have tried to capture analytically such networks and their interdependencies across different governance levels. While emphasising the importance of local entrepreneurial initiatives, experimentation and learning-by-doing, polycentric climate governance concepts (Ostrom 2009(Ostrom , 2014) have stressed the significance of self-organisation, trust building and site-specific conditions (e.g. Morrison et al. 2017, Jordan et al. 2018. Cognitive leadership/pioneership involves defining and redefining interests and developing innovative ideas such as the 'green economy' or low carbon economy, which aim to generate 'green' jobs while reducing GHGE. Cognitive leadership/pioneership may conceptualise climate change not only as a threat but also as an opportunity. It may also relate to branding/rebranding strategies with the aim of improving the external image of SDCs (e.g. from climate laggard to leader or pioneer), which try to attract inward investment and skilled people to the city. Such rebranding goes well beyond superficial 'greenwashing' or symbolic climate leadership/pioneership if significant GHGE reductions support it. The urban governance literature has emphasised the importance of cities and regions as laboratories for experimentation and innovation (e.g. Betsill 2005, Ostrom 2009) although little is known about whether SDCs can fulfill similar functions.
Finally, exemplary leadership/pioneership refers to the setting of examples for others, either intentionally or unintentionally. Intentional exemplary leaders put forward climate governance measures as models for others. Unintentional example setting, in contrast, refers to pioneers who do not intentionally aim to attract followers . Cities that adopt the Covenant of Majors usually try to set a good example that they would like others to follow (e.g. Bulkeley et al. 2015). Such cities therefore act as climate leaders. However, adoption of innovative urban climate governance measures may involve no intention of setting an example for other cities, thus amounting to climate pioneership rather than leadership. Liefferink and Wurzel (2017) differentiate between internal and external ambitions, arguing that an actor with high internal and low external ambitions acts as a pioneer with no explicit intention to attract followers (see also Wurzel et al. 2017this volume). We argue that SDCs may well have high internal climate ambitions that they do not normally use to attract followers. We therefore use the term pioneership to refer to internal climate ambitions of SDCs (rather than their external ambitions which would amount to leadership).
These four different types of leadership/pioneership can be combined analytically with the following two leadership/pioneership styles, namely transactional and transformational . Transactional leadership/pioneership refers to incremental changes usually over a relatively short time horizon while transformational leadership/ pioneership aims at profound or even 'revolutionary' changes usually over a comparatively long time period. Transactional climate leadership/pioneership resembles efforts to make cities more resilient to climate change although such efforts can lead to a 'resilience trap' (Kythreotis and Bristow 2017) that merely reinforces the status quo. However, transactional leadership/pioneership extending over a very long timescale may eventually also trigger transformational change (e.g. Burns 1978).

Urban climate strategy
In Bremerhaven, local climate governance experienced a substantial boost and institutionalisation with the approval of the Climate City (Klimastadt) concept in 2010. Its adoption followed a motion in the city parliament (Bremerhavener Stadtverordnetenversammlung) in 2007 and the publication of a conceptual study in 2009 (AWI 2009). The full name of the Klimastadt is Kurs Klimastadt, which translates as 'on course to becoming a climate city' and 'resonates well with the maritime image of Bremerhaven' (Interview, 2016). As one climate city office (Klimastadtbüro) staffer emphasised: 'We are not yet a climate city. We are on course to becoming one' (Interview, 2016). As we explain below, Bremerhaven's climate city concept identified not only municipal steering and monitoring instruments but also proposed the creation of an innovative green economy cluster that, until the mid-2010s, focused almost exclusively on the offshore wind energy industry.
In 2006, Bremerhaven followed Bremen's lead by applying for the European Energy Award (EEA) certification scheme to establish a monitoring and implementation tool for climate management. Five years later, Bremerhaven achieved the scheme's requirements and obtained the EEA award. In 2007, Bremerhaven prepared a research and development concept with the aim of transforming the existing network of climate-related institutions into a flagship project while trying to exploit its full economic potential. The concept focused on the following three 'climate lighthouses' (Klimaleuchttürme): regional business promotion in the offshore wind energy sector; top-level, climate-related research activities; and tourist attractions such as the climate house (Klimahaus) museum (Mederake 2015). Initiated by a Christian Democratic Union (CDU) and Social Democratic Party (SPD) local government coalition in 2008, Bremerhaven City Council adopted a Master Plan Active Climate Policy as strategic frame for local state and non-state climate measures.
In 2010, Bremerhaven launched the climate city Bremerhaven (Klimastadt Bremerhaven) initiative with the aim of improving its poor external image, strengthening its climate-related capacities, boosting jobs in the offshore wind energy sector and reducing GHGE. At the centre of the climate city project was the attempt to raise Bremerhaven's internal climate ambitions with the aim of changing its negative image in order to attract external investment. Bremerhaven adopted important infrastructure measures while providing advice to potential investors through the Bremerhaven Economic Development Company and City Development (Bremerhavener Gesellschaft für Investititionsförderung und Stadtentwicklung-BIS), which increased its staff and knowledge resources on offshore wind energy. Bremerhaven thus positioned itself as a climate pioneer while offering especially entrepreneurial and cognitive pioneership. With the adoption of its climate city project, Bremerhaven opted for a transformative pioneership style, which was aimed at mitigating climate change while transforming the city's economic fortunes with the help of the offshore wind energy industry.
Following local elections for Bremerhaven's City Council in 2011, a 'Red-Green' coalition government of the SPD and the Greens replaced the CDU-SPD coalition. The 2011 local elections had occurred shortly after the Fukushima nuclear catastrophe, which greatly boosted the electoral support for the Greens who secured (among other posts) the Environmental Councillor (Umweltdezernentin). At the request of the Greens, the focus of the Klimastadt project widened from a relatively narrow focus on 'green' business activities (the offshore wind energy sector) to include also public participation initiatives with civil society actors. Largely on the insistence of the new Green Environmental Councillor, the climate city office (Klimastadtbüro), which had been set up in 2014, moved to new premises in a prime location in the city centre where it opened its doors for the general public in 2015. However, the need for budget cuts and changed political priorities of the CDU-SPD government newly elected in Bremerhaven in 2015 triggered a moderate reduction in staff and the Klimastadtbüro's relocation to cheaper, more remote premises in 2017.
Bremerhaven's local climate governance targets became more ambitious as a consequence of programmes developed by the Land Bremen, which a SPD-Greens coalition has governed since 2007. The Land Bremen adopted the Climate Protection and Energy Policy Programme 2020 (Klimaschutzund Energieprogramm 2020 -KEP 2020) for Bremen and Bremerhaven in 2010 (SUBV 2010). The KEP set an ambitious 40% reduction target for CO 2 by 2020 (compared to 1990). Consequently, Bremerhaven also committed itself to reducing CO 2 emissions by 40% by 2020, reduction targets that were strengthened when the Bremen State Climate and Energy Act 2015 included them (Bremisches Klimaschutz-und Energiegesetz).
Hull's Environment & Climate Change Strategy 2010-2020, published in 2010, also set ambitious CO 2 emissions reduction goals. It noted the EU's legally binding 20% and the UK's 32% reduction goals for 2020 and adopted the somewhat more ambitious goal of between 32% and 45% emissions reductions by 2020 (Hull City Council 2010). Since the publication of the 2010 Strategy, funding cuts imposed by central government on UK local government have had an adverse effect on the willingness and ability of Councils to fund climate action (Eckersley 2018) and their ability to offer climate pioneership. However, funding cuts have promoted independent power generation from renewable sources and energy efficiency measures to save money.
Since 2011, Hull Council has published annual CO 2 emissions reports. Efforts to reduce emissions include the deployment of photovoltaic panels on Council buildings and the replacement of street lighting with LED bulbs. Hull City Council partnered with 'green economy' and third sector actors to create the Green City Group in 2011 to consider the branding of Hull as a Green City, in a similar but coincidental manner to Bremerhaven's Klimastadt project. Ultimately, with the adoption of Hull's City Plan the Council made the decision to market Hull instead as Energy City (Hull City Council 2013). Whilst this represented an ideational shift away from outright climate pioneership to an economic marketing strategy, the City Council has nevertheless demonstrated some local climate pioneership. Unlike in Bremerhaven, one political party (Labour) has dominated post-Second World War local politics in Hull, with the exception of 2007-11 when the Liberal Democrat Party held the majority. Other political parties, such as the Green Party and the United Kingdom Independence Party (UKIP), have had little influence in local government.
Especially when considering the vulnerability of maritime port cities to climate change (e.g. sea water level rise) and SDCs' resource constraints, it is perhaps surprising that Bremerhaven and Hull adopted a significant number of climate mitigation initiatives instead of solely supporting adaptation activities. Post-Second World War Bremerhaven has suffered from significant flooding events in 1962,1999,2006 and 2016, while Hull has been affected by major flooding in 1953, 2007 and 2013 (see Table 2). Recent serious flooding events have helped local officials in both cities to push climate change higher up the local government agenda (Interviews, 2014-2017). As one Hull City Council official stated, flooding has been key in developing the city's climate actorness: 'From the experience in 2007 with the floods there and the 2013 tidal surge, we're a lot further ahead than a lot of cities'.

Societal participation strategies
Bremerhaven's Klimastadt programme set up six working groups in which local government, civil society, and business actors cooperate on: economy/ science, citizens and education, construction and modernisation of buildings, communication, mobility, and sustainable tourism. Additional innovative participatory elements in the Klimastadt project included an annual festival-like climate day (Klimatag) and, since 2014, a Youth Climate Council (Jugendklimarat) which has a small budget and the right to speak in the City's Environmental and Construction Committee. In 2013, the Klimastadt funded the transdisciplinary festival Odyssee Klima (Odyssey climate) in which Bremerhaven's city theatre (Stadttheater) took on a leading role. The festival featured climate change related plays and performances by actors and scientists in Bremerhaven's city centre and in wind turbine production factories (Interviews, 2014-17).
Hull's status as the UK's City of Culture in 2017 involved few climaterelated activities. When compared to Bremerhaven, societal participation has remained underdeveloped in Hull's climate governance strategy. Hull's adoption of the Energy City brand aimed mainly at business and 'green economy' actors rather than at societal actors. However, Hull used its status as the UK's City of Culture in 2017, albeit hesitantly, to raise public attention to climate change-related issues (Interview, 2016). One example, 'The Blade' installation, involved exhibiting a 75-metre rotor blade of an offshore wind turbine in the city centre in early 2017. Another was an exhibition entitled 'Somewhere becoming Sea' which focused on the everchanging boundaries between land and sea while trying to capture 'the sea's elemental power . . .[a]t a time when climate change threatens to blur boundaries further and bring far-reaching economic impact' (Hull UK City of Culture 2017). The green economy In Bremerhaven, the Land Bremen and the city of Bremerhaven identified the offshore wind energy industry and, to a much lesser degree, the onshore wind energy industry as potential major growth sectors in 2003. This occurred against the background of ambitious national renewable energy targets, generous subsidies for renewable energy and the decision to phase out nuclear power in Germany. There was a concerted attempt to turn easy access to the sea, disused industrial facilities (e.g. from shipyards) and derelict land together with underutilised maritime-related job skills into an advantage. Substantial investment and various state and city agencies (including the BIS) facilitated the creation of an offshore wind energy cluster in Bremerhaven. Highly regarded, nationally funded research facilities such as the Alfred-Wegener-Institut (AWI) and Fraunhofer Institute for Wind Energy and Energy System Technology (IWES) moved to Bremerhaven in 1980 and 2009, respectively. Sectoral associations and specialised networks for the offshore wind energy sector (e.g. the wind energy agency Bremerhaven (Windenergie Agentur Bremerhaven -WAB)) also came into being. The WAB became an important network, which provided entrepreneurial pioneership in the form of networking opportunities for the fledgling offshore wind energy industry in Bremerhaven and the wider region. The University of Applied Sciences Bremerhaven (Hochschule Bremerhaven) offered specialised academic training programmes, thus strengthening Bremerhaven's cognitive pioneership capacities. In short, the local government in Bremerhaven tried to create, with the support of in particular businesses, entrepreneurial and cognitive pioneership capacities for the offshore wind energy industry. Its structural pioneership capacities relied primarily on economic support from the Land Bremen and/or federal government funds. In 2014, the offshore wind energy industry reached a peak with around 3,500 jobs in Bremerhaven (Written communication, BIS, 2017). The joint efforts of Bremerhaven and the Land Bremen led to the establishment of a leading offshore renewable energy industry cluster that included companies such as Adven (formerly Areva) and Senvion (previously RePower) as well as WeserWind, which became insolvent in 2015, and PowerBlades which decided to closed its factory in Bremerhaven in 2018. Arguably the concerted action by Bremerhaven in cooperation with the Land Bremen amounted to local government structural leadership with the aim of transforming the city's socio-economic structure.
As a result of the offshore wind energy industry boom, the Senate of the Land Bremen adopted plans for an Offshore Terminal Bremerhaven (OTB) in Bremerhaven at an estimated cost of €180 million in 2010. However, they were halted at least temporarily when the environmental NGO, BUND (Friends of the Earth Germany), took legal action against its construction, arguing that the OTB was no longer economically viable. As a consequence of reforms to the German Renewable Energy Law (Erneuerbare-Energien-Gesetz -EEG) in 2014 and 2016, funding for offshore wind energy production decreased significantly. The federal government also adopted a twoyear moratorium for the expansion of offshore wind farms in the North Sea while government funding was diverted for political reasons to offshore wind farms in the Baltic Sea, which economically benefit the northern coastal state in the former East Germany. The combination of these measures significantly dampened hopes for ambitious expansion plans for Bremerhaven's offshore wind energy capacity. The number of direct and indirect jobs in the offshore wind energy sector in Bremerhaven, which peaked at approximately 3,500 in early 2014, fell to about 1,500 staff in 2017 (Written communication, BIS, 2017). The main reason for this steep decline was that WeserWind, which had employed approximately 1,200 staff in 2012-2013, went bankrupt in early 2015. In the same year Siemens, one of Europe's leading offshore wind turbine producers, invested in a new factory in neighbouring Cuxhaven while its wind turbine production facilities across the North Sea in Hull became operational in early 2017. Moreover, Powerblades, which had a staff of about 300 in Bremerhaven in 2017, announced plans to relocate its plant in early 2018. Consequently, Bremerhaven has tried to broaden its relatively narrow focus on the offshore wind energy industry towards a wider focus on the green economy (Interviews, 2017).
Hull's climate pioneership is mainly the result of the adoption of green economy measures and a municipal drive towards climate change mitigation and adaptation. Compared to Bremerhaven, Hull's adoption of climate governance measures is more hesitant. Whilst Hull exhibited climate pioneership somewhat later than Bremerhaven, its green economy measures have been less narrowly focused on the offshore wind energy sector while including also other forms of renewable energy such as biomass. Hull has become a centre for the biofuel industry, which is however not without its environmental critics (e.g. Mol 2010). Associated British Ports (ABP) along with the Spencer Group, a Hull-based engineering company, developed a biomass terminal and storage facility for fuel for the formerly coal-fired Drax power plant (in North Yorkshire). Within Hull itself, Vivergo Biofuels, a co-venture by BP, AP Sugar, and DuPont, was the largest biorefinery in the UK when it opened.
Despite the decline of the fishing industry, a section of Hull's port-based industry stayed active. The ports act both as cargo and ferry terminals. However, the gap left by the decline of the city's primary industry led to the recognition that a new major industry was needed to give the city 'a renewed raison d'etre' (Interview, 2016). It is into this gap that Hull actors ushered the green economy. Here 'gap' refers to both an economic and physical space which made Hull an attractive site for Siemens when considering the placement of a new blade manufacturing and offshore wind turbine assembly facility. As well as the brownfield and quay space in Hull, the city's location close to important UK offshore wind farm sites, made it a particularly suitable development location (Jonas et al. 2017). Hull City Council, local MPs and national politicians were able to secure the Siemens facility as part of a £310 million joint venture with ABP which manages four important regional ports: Hull, Goole, Grimsby, and Immingham. The Siemens-ABP facility opened in early 2017. From initial plans to produce 450 blades a year, Siemens has increased its intended yearly output to 600 blades for deployment in 6MW turbines in UK waters and further afield. However, the UK's decision to leave the EU has put in question Siemens' future ability to use its Hull production site for exports to the EU. By 2017 the site created 1,000 direct jobs, 95% of whom were from the region. The Siemens-ABP Green Port Hull development is Hull's most high-profile green economy development, but there are also other local green economy projects.
Spurred on by the achievement of attracting Siemens to Hull, local economic development practitioners have seen an opportunity to address the city and region's longstanding structural disadvantages. In other words, local governance actors have tried to adopt a transformative pioneership style. In 2013, Hull approved a 10-year City Plan to attract £1bn in investment and create up to 8,000 new jobs for local job seekers over the next 10 years (Hull City Plan, 2017). A central component of the City Plan was Energy City, an umbrella term for flagship industry projectsthe majority of which can be classed as part of the green economy. A key driver in Hull's proposed economic transformation has been the Humber Local Enterprise Partnership (LEP). In 2013, LEPs replaced Regional Development Agencies as private sector-led economic development organisations, albeit retaining significant public sector representation. In its Strategic Economic Plan, the Humber LEP recognised that addressing climate change is essential to the competitiveness of Hull because of the need for building inward investor confidence and reducing flood risk. Nevertheless, although the LEP has recognised the wider social and environmental benefits of climate adaption, its priority is to support mainstream economic development, including 'green' jobs. LEP's main goal is to put 'the Humber [at] the centre of renewable energy [in the UK]so that when people think of energy they will think of the Humber' (Interview, Hull, 2014).
The evolution of the renewables sector in Hull demonstrates the city's belated structural pioneership, which could turn out to have been an advantage. The city has become home to an established, market-dominant player -Siemens. If Hull had pushed for such an offshore wind production base earlier, it possibly would have been harder to find such an established partner. The insolvency of WeserWind and the relocation of Powerblades in Bremerhaven as well as Siemens' investment in neighbouring Cuxhaven illustrate the risk that structural local climate pioneership poses for SDCs. The 'first mover' advantage, which has been identified for states and companies (e.g . Porter 1990), may possibly play out differently at the city levelat least for SDCs. Hull closely followed Bremerhaven's exemplary pioneership. By sending delegations to Bremerhaven, Hull tried to learn lessons from one of Europe's offshore wind energy pioneers. However, lesson-drawing quickly turned into competition for investmentas Bremerhaven was also a city considered for the Siemens plant now housed in Hull. This shows that there is a thin dividing line between learning from best practice generated by local climate experimentation and fierce economic competition between SDCs wanting to attract investment from transnational corporations (Kemmerzell 2017).
Explaining urban climate governance in SDCs: multi-level, polycentric or place-specific?
MLG concepts have emphasised the mutual dependency of governance actors at different governance levels (e.g. EU and subnational levels). In contrast, polycentric governance concepts usually attribute a higher degree of autonomy to subnational actors (e.g. cities and regions) and societal actors (e.g. business, NGOs and individual citizens) as regards experimentation with innovative local climate governance measures and learning-bydoing. Put simply, while MLG concepts tend to focus on the globalization (or 'glocalisation') and, within the European political context, the Europeanisation of regional and local actors (e.g. Hooghe 1996), polycentric governance concepts stress the crucial role that local climate governance experiments play for the success of global climate governance regimes (e.g. Ostrom 2009).
Polycentric governance concepts share certain core presuppositions (e.g. multiple centres of authority and levels of governance) with MLG approaches, although conceptually they are not identical (Homsy and Warner 2015, Jordan et al. 2018. By comparison with MLG approaches, polycentric concepts normally assume a stronger role for societal actors and attribute a high degree of autonomy to both subnational actors (e.g. cities) and non-governmental societal actors (Ostrom 2009(Ostrom , 2014. Polycentric governance approaches usually emphasise the importance of bottom-up local governance and argue that local climate governance ought to supplement, if not partly supplant, global climate governance initiatives. Broadly speaking, proponents of polycentricity favour societal self-coordination within market-like governance structures (e.g. Ostrom 2014, for critical reviews see Morrison et al. 2017, Singleton 2018 while MLG advocates support the creation of networks in which governmental actors (including supranational EU actors) play an important, if not dominant, role, e.g. to correct negative market externalities (Hooghe 1996, Homsy andWarner 2015).
Proponents of polycentricity usually argue in favour of a multitude of decision-making 'centres' and widespread subnational societal self-coordination in climate governance (e.g. Ostrom 2009Ostrom , 2014. From a polycentric perspective, one would normally expect smaller and more independent cities to exhibit greater degrees of climate leadership/pioneership. At first sight, the empirical findings presented above might suggest that it is 'game, set and match' for polycentric governance perspectives as Bremerhaven, which has exhibited a higher degree of climate innovation, is smaller and enjoys a greater degree of local governance independence compared to Hull. However, our empirical findings also show Bremerhaven's high dependency (especially for structural climate pioneership) on decisions that were taken on the national governance level. Prominent examples are the reforms of the EEG and its detrimental impact on the offshore wind energy industry in Bremerhaven. Our findings therefore emphasise the importance of MLG structures and concepts.
Both Bremerhaven and Hull took account of national and EU CO 2 reduction targets when setting their local reduction targets. As explained above, for Bremerhaven the CO 2 reduction targets of the Land Bremen were also of crucial importance while for Hull no such additional layer of local climate governance existed.

Conclusion
Here, we have assessed how small-to-medium-sized SDCs (Bremerhaven and Hull) have responded to climate change by developing climate pioneership capacities at the urban level. Based on our empirical evidence, Bremerhaven exhibited a higher degree of experimentation and innovation in local climate governance than Hull, which focused more on the mainstreaming of innovative local climate action within economic development, with the latter remaining dominant. Bremerhaven's climate city (Klimastadt) concept clearly goes well beyond Hull's Energy City concept in terms of local climate governance innovation. While offering exemplary pioneership, Bremerhaven has adopted slightly more ambitious mediumterm CO 2 reduction goals than Hull .
Hull initially acted as a follower in relation to Bremerhaven in terms of creating offshore wind energy industry capacities although it overtook Bremerhaven in the late 2010s. There are concerns about Bremerhaven's ability to maintain climate pioneership over a long time period, which is usually required to produce transformative effects, without additional support from a 'higher' governance level (e.g. the Land Bremen, federal government and/or EU). The long-term success of Bremerhaven's transformative pioneership may also require some modification, which is not unusual for learning-by-doing local climate experiments and innovation. For example, Bremerhaven's initial narrow focus on the offshore wind energy sector as a transformative industrial sector had to be broadened to encompass the wider green economy following significant changes at the national governance level (e.g. the reforms of the EEG) which had a detrimental effect on the offshore wind energy industry in Bremerhaven.
As we have focused only on two case study cities, we are able to draw only tentative general conclusions about innovative climate governance in SDCs, which have remained under-researched. Further research is necessary to show whether our empirical findings are indeed representative for SDCs. Such research ought also to assess critically whether the use of the pioneer and leader concept indeed adds analytical value to critically assessing local climate governance. With this in mind, we put forward the following five main conclusions.
First, considering their structural disadvantages it would be reasonable to assume that SDCs act primarily as climate laggards or at best as followers. However, our empirical research has clearly shown that SDCs do not necessarily act as climate laggards but instead can become climate pioneers or at least followers.
Second, SDCs seem to conceptualise climate change not only as a threat (flooding) but also as an opportunity ('green' jobs). To be able to exploit such opportunities, SDCs have to create cognitive and entrepreneurial pioneership capabilities that require the involvement of local governance actors, businesses, NGOs and citizens. However, to create considerable structural pioneership capacities, SDCs are significantly more reliant on (e.g. financial) support from 'higher' levels of governance such as regional and national governments or the EU (see also Morrison et al. 2017).
Third, arguably because of their deep-rooted economic and social problems, SDCs seem relatively willing to endorse transformational climate pioneership styles in the hope of turning their economic fortunes around and improving their poor external image. However, a long term transformational climate pioneership style is contingent on being compatible with core local economic goals, strong support from local governance actors (including local officials, political parties, businesses and societal actors) and at least some support from 'higher' levels of governance.
Fourth, for SDCs there is a tension between learning from each other's best practice in terms of local climate experiments and innovation, and fierce economic competition for inward investment for 'green' jobs (e.g. in the offshore wind energy sector).
Fifth, Liefferink and Wurzel (2017) claim that environmental pioneers and leaders are either 'first in class' or 'best in class' applies to SDCs only to the degree that these cities are more often than not able to show pioneership in their particular place in the urban system, namely structurally disadvantaged maritime port cities. Comparing Bremerhaven and Hull with cities other than SDCs would therefore be akin to comparing apples with oranges. This poses an analytical challenge for the state-focused leader and pioneer typology proposed by Liefferink and Wurzel (2017) because there are arguably more different types of cities than there are different types of states. The applicability of different leadership typesstructural, entrepreneurial, cognitive and exemplaryis challenging for assessing urban climate governance although it can add analytical value. Focusing on different types of pioneership (and leadership) creates greater analytical awareness of the fact that SDCs may, for example, try to attract renewable energy industry (structural leadership), build extensive networks and new climate alliances within the city as well as across different governance levels (entrepreneurial leadership) and conceptualise climate change not only as a threat but also as an opportunity when attempting to rebrand the city with the help of innovative local climate innovations (cognitive leadership).
Place clearly makes a difference to how analytical concepts (such as the pioneership/leadership concept) assess local climate governance actions within MLG and polycentric governance structures. The need to make concepts place-specific suggests the importance of contextual factors, which may differ significantly even for the same or similar types of cities such as small-to-medium-sized SDCs. As Le Galés (2002, p.268) has pointed out: 'Each city represents something unique [which is] the result of a unique history'. There are therefore certain path-dependencies, which SDCs with limited resources will find difficult to alter radically. Perhaps the key message is that the analysis of climate change policy in SDCs can be helpful in demonstrating how concepts of environmental leadership originally designed for international and national comparisons can also be applied to the urban scale. Moreover, as much as it sheds light on largescale trends towards multi-level and polycentric climate governance, urban comparative analysis also helps to expose differences in how climate leadership plays out at the urban scale. Clearly we need additional research on SDC climate governance to build more robust generalisable conclusions.