Table S1. Indicators or proxies used to evaluate degree of horizontal and vertical alignment, used to inform spatial mapping and analysis in Figure 1. Gray shading indicates that alignment is present within a particular category. Table assesses the alignment present during the initiation and implementation of a project or policy. The pro-climate policy category reflects the ratings of the Climate Action Tracker. Although regional and national networks of peer cities and regions supported the implementation some of the initiatives listed here, a full consideration of these non-TCG horizontal connections is beyond the scope of this study. Full descriptions of each case can be found in Hsu et al. (2015), although we consider an expanded scope of several cases here. Source: authors.

Sub-national Case Study / National Climate Policy / Alignment Direction / Capacity Building / Regulative/Rule Setting / Information sharing / Alignment Pathway
Integrated Solid Waste Management in Oran, Algeria / Not evaluated in Climate Action Tracker / Vertical / ------/ Consultation from regional and Algerian government (National Waste Agency). / National framework through the National Program of Municipal Waste Management (PROGDEM). Task Force on Waste Management declared an official provincial task force. / Synergistic.
Horizontal / Financial and capacity-building support from R20.[1] / MRV conducted by R20 and local authorities. / Lessons from other projects incorporated by R20 in project design. Task Force on Waste Management includes R20, private companies, and regional administrators.
Forest Conservation in Acre, Brazil / Medium / Vertical / Funding from the Brazilian Development Bank.[2] / Acre designed its REDD+ framework to harmonize with Brazil’s National Climate Change Policy. / Policy connections through Brazil’s national deforestation target and INDC.[3] / Synergistic.
Horizontal / Funding or assistance accessing carbon markets from Verified Carbon Standard, KfW, Norwegian International Climate and Forest Initiative. [4] / The Governors’ Climate and Forests Task Force (GCF) [5]and the REDD Offsets Working Group (ROW)[6] supports MRV. / Creation of policy framework through Governors’ Climate and Forests Task Force (GCF)5 and agreements or MOUs with carbon markets in California, Sao Paulo and Rio de Janeiro.[7] Member of New York Declaration on Forests and Under2MOU.[8]
Integrated Waste management in Belo Horizonte, Brazil / Medium / Vertical / Funding from Brazilian government.[9] / Belo Horizonte’s Municipal GHG Inventory collects data on the city’s waste management work. / Policy connections through Brazil’s 2010 National Policy for Solid Waste, which shapes Belo Horizonte’s 2012 Urban Municipal Cleansing Law and was shaped by the city’s ISWM strategy.[10] / Synergistic.
Horizontal / ------/ Reporting through the Compact of Mayors and carbonn Climate Registry and CDP.[11]
Carbon Tax in British Columbia, Canada / Inadequate / Vertical / ------/ Data collection implemented at the sub-national level (though reflected in national datasets) / Canada is a member of the Carbon Pricing Leadership Coalition, but joined the Coalition after the carbon tax was implemented. In 2016 Canada required all provinces and territories to introduce carbon pricing by 2018.[12] / Independently driven.
Horizontal / ------/ ------/ British Columbia is a member of a number of TCG networks,[13] but joined after these organizations after the initiation of the carbon tax.
Vehicle Standards in California, USA / Medium / Vertical / California coordinated with the federal government in crafting its Advanced Clean Car standards.[14] Cities will support the roll-out of electric vehicles.[15] / Advanced Clean Car policy sits within and will operate through framework of Clean Air Act, but impetus for higher standards originated within the state.
The Advanced Clean Car program builds on the Pavely act, a California law. National standards were harmonized with the Pavely Act in 2009, under the authority of the Clean Air Act and the Energy Independence and Security Act of 2007. / California’s Advanced Clean Car Standards are part of the state’s Global Warming Solutions Act (AB32), which does not originate from national-level U.S. policy. / Independently-driven.
Horizontal / ------/ Under Section 177 of the Clean Air Act, other US States can adopt California vehicle standards. Fifteen states have adopted California vehicle standards for criteria pollutants, and nine have done so for zero-emission vehicles.[16] [17] / California’s membership in the Compact of States and Regions and Under 2 MOU followed AB32 and the Advanced Clean Car Standards. The ZEV Alliance,[18] Pacific North America Climate Agreement,[19] Pacific Coast Action Plan on Climate and Energy,[20] West Coast Electric Fleets,[21] will support but follow the passage of the Standards.
Emissions Trading in Shenzhen, China / Medium / Vertical / Shenzhen received general economic support and tax benefits from its status as a Special Economic Zone. / Links between national and local ETS established by NDRC’s Provisional Regulation on Carbon ETS. / Shenzhen’s ETS will be linked to a future national ETS, as outlined in China’s 12th Five-Year Plan (FYP). / Synergistic.
Horizontal / ------/ Shenzhen established MRV based on ISO 14064-1, which is based on the WRI/WBCSD GHG Protocol. / Active participation in TCGs for carbon markets, as noted by Roger and Hale (2012), played a role in China’s choice to develop regional ETS pilots.
Harnessing Industry in Hamburg, Germany / Medium / Vertical / ------/ Data collection implemented at the sub-national level (though reflected in national datasets) / ------/ Horizontally-aligned.
Horizontal / ------/ Hamburg reports data on its overall climate action progress to the Covenant of Mayors, and is a member of the Climate Alliance. / Hamburg is a member of the Covenant of Mayors and the Climate Alliance, but joined after the initiative of its partnership with industry.
Solar Power in Rajasthan, India / Medium / Vertical / ------/ Data to support state-level renewable investment provided through the Solar Data Sharing and Accessibility Policy. / Rajasthan’s state-level policy supports India’s national policy for renewable energy, the Jawaharlal Nehru National Solar Mission. / Vertically aligned.
Horizontal / ------/ ------/ ------
Energy Efficiency in Cape Town, South Africa / Inadequate. / Vertical / National grant and loan helped finance initial project phases.[22] / Data was provided to the national government after the project was completed, but the city government oversaw project implementation. / ------/ Synergistic.
Horizontal / Funding from the Western Cape province, private finance, and international funding channeled through non-profit organizations helped implement the project. NGOs including South South North and Sustainable Energy Africa provided capacity.[23] / The project is reported in the carbonn Climate Registry. / Cape Town is a member of the Compact of Mayors and C40 Cities, but joined these networks after the implementation of the Kuyasa energy efficiency project.

References

Environmental Defense Fund. Ready for REDD: Acre’s State Programs for Sustainable Development and Deforestation Control. Retrieved from: http://www.edf.org/sites/default/files/Acre_Ready_for_REDD_EDF.pdf

Hale, T. & Roger, C. (2012). Chinese Participation in Transnational Climate Governance. In From Rule takers to Rule Makers: The Growing Role of Chinese in Global Governance, ed. Scott Kennedy and Shuaihua Cheng. RCCPB and ICTSD.

Hsu A., et al. (2015). The Global Impact of Sub-national Climate Action. R-20 Regions for Climate Change. Retrieved: http://regions20.org/images/ScalingUp.pdf.

Trudeau, J. (2016). Prime Minister Trudeau delivers a speech on pricing carbon pollution. Government of Canada. Retrieved: http://pm.gc.ca/eng/news/2016/10/03/prime-minister-trudeau-delivers-speech-pricing-carbon-pollution.

VCS. (2 October 2014). The road to zero-deforestation: Lessons from Brazil. Retrieved: http://www.v-c-s.org/news-events/news/road-zero-deforestation-lessons-brazil.

2

[1] R20 Regions of Climate Action (R20) is a coalition of regional governments, see http://regions20.org/.

[2]Acre has signed an agreement with the Brazilian Development Bank to integrate carbon offsets from Acre into current or projected carbon markets or cap-and-trade programs (VCS 2014).

[3] Brazil’s Intended Nationally Determined Contribution (INDC) notes that Brazil’s intention to strengthen and enforce the implementation of the Forest Code, the legislation outlining the deforestation target that Brazil has adopted, “at federal, state and municipal levels,” see http://www4.unfccc.int/submissions/INDC/Published%20Documents/Brazil/1/BRAZIL%20iNDC%20english%20FINAL.pdf.

[4] In December 2012, Acre and the German Development Bank (KfW) signed an agreement in which KfW would provide up to EUR $19 million over four years, to support Acre’s efforts to cut GHG emissions from deforestation, through its System of Incentives for Environmental Services (SISA), which rewards local landowners for protecting the forest and supports the implementation of REDD+ (Environmental Defense Fund & IETA, 2015).

[5] The Governors’ Climate and Forests Task Force (GCF) includes six Brazilian states and 22 states and provinces from Brazil, Indonesia, Mexico, Nigeria, Peru, Spain, and the United States, and “develop[es the technical, legal, and institutional frameworks for comprehensive jurisdiction-wide programs to reduce emissions from deforestation and land use” (Environmental Defense Fund & IETA, 2015).

[6] The REDD Offsets Working Group (ROW) included the states of Acre, Brazil; California, USA and Chiapas, Mexico, and worked towards establishing sectoral offset programs from REDD.

[7] VCS (2014).

[8] In its appendix to the Under2MOU, Acre describes its deforestation prevention strategies, including the System of Incentives for Environmental Services (SISA) law. See http://under2mou.org/wp-content/uploads/2015/05/Acre-appendix-English.pdf.

[9] The Brazilian government provided funding, in part because it believed Belo Horizonte’s waste management strategies could provide a template for other local authorities nationwide (Centre for Public Impact 2016).

[10] See Urban Low-Emissions Development Strategies: http://urbanleds.iclei.org/index.php?id=127&tx_ttnews%5Btt_news%5D=130&cHash=77353c7910e67565428d8b86fbf8618a.

[11] Belo Horizonte’s submission to the carbonn Climate Registry, as part of its participation in the Compact of Mayors, includes sets a city-wide mitigation goal between 2007-2030, and its description of its activities includes elements of the city’s waste management strategy (i.e., composting and construction waste recycling programs, recycling collection through the city’s Integrated Solid Waste Management Model, and the Biogas Energy Use Center).

[12] Trudeau (2016).

[13] These networks include the Carbon Pricing Leadership Coalition, International Carbon Action Partnership, The Climate Registry, Western Climate Initiative, Compact of States and Regions, and Under 2 MOU. Through the Carbon Pricing Leadership Coalition, leaders from government, business, and civil society work towards the long-term objective of a carbon price applied throughout the global economy. British Columbia, along with Ontario and Quebec, are members of the International Carbon Action Partnership, is an international forum for governments and public authorities that have implemented or are planning to implement emissions trading systems. The Climate Registry designs and operates voluntary and compliance GHG reporting programs globally, and consults with governments nationally and internationally on all aspects of GHG measurement, reporting, and verification. Western Climate Initiative, Inc. supports the implementation of state and provincial greenhouse gas emissions trading programs.British Columbia, along with three other Canadian provinces, joined the Initiative in 2008. In its appendix to the Under2MOU, British Columbia highlights its role as the first North American jurisdiction to introduce a carbon tax and require greenhouse gas emissions reduction targets by legislation. British Columbia reports on its progress in implementing its climate action commitments through the Compact of States and Regions.

[14] Interview 4 (2016).

[15] Interview 4 (2016).

[16] TrasnportPolicy.net. Retrieved: http://transportpolicy.net/index.php?title=US:_Section_177_States.

[17] Interview 4 (2016).

[18] The International ZEV Alliance includes countries and U.S. and Canadian regions committed “to make all passenger vehicle sales in our jurisdictions ZEVs as fast as possible, and no later than 2050.”

[19] In the Pacific North America Climate Leadership Agreement, regions and cities on the Pacific Coast of North America pledge to, among other goals, “Develop and implement approaches that encourage consumer adoption of Zero Emission Vehicles (ZEVs) through incentives and by urging manufacturers and retailers to increase the volume and variety of ZEVs commercially available in Pacific Coast markets” see http://pacificcoastcollaborative.org.

[20] The Pacific Coast Collaborative (PCC), a joint initiative of California, Oregon, Washington, and British Columbia announced the Pacific Coast Action Plan on Climate and Energy. The plan calls on governments to “take actions to expand the use of zero-emission vehicles, aiming for 10 percent of new vehicle purchases in public and private fleets by 2016.” see http://pacificcoastcollaborative.org.

[21] The PCC “launched West Coast Electric Fleets Initiative and developed this toolkit for public and private fleet managers to quickly assess opportunities for ZEVs and access useful incentives and resources to assist with procurement.”

[22] The National Department of Environmental Affairs played a particularly strong role in supporting the beginning phases of the project at the national level, due to the fact that it saw the project as a test case for strategies for tapping into the CDM and carbon credit markets to fund climate and sustainable development activities (Interview 6 2016).

[23] Sustainable Energy Africa promotes equitable, low carbon, clean energy development in urban South Africa and Africa.