Global Covenant of Mayors for Climate and Energy (GCoM)

GCoM requires participating subnational governments to establish emissions targets and goals, implement policies that will meet those targets, and enter a standardized data reporting framework. For their part, the Covenant provides its participants with planning guidance, technical assistance, connections to funding sources, reporting templates, and helpdesk support. ³

Additionally, GCoM seeks to give city climate plans a larger role in national climate policy. It has called for national governments to include those plans in official national climate pledges and for governments and financial institutions to direct more funding, authority, and project support to cities. ⁴

GCoM is one of several Bloomberg-backed climate and environmental initiatives, alongside C40 Cities, Beyond Carbon, Beyond Petrochemicals, America Is All In, and the Youth Climate Action Fund. ⁵

Background

The Global Covenant of Mayors for Climate and Energy (GCoM) was formed by the merger of two previous initiatives: the Compact of Mayors and the European Union’s Covenant of Mayors. ⁶  The Compact of Mayors had been launched in 2014 by Michael Bloomberg and then-United Nations Secretary-General Ban Ki-moon to coordinate city commitments to reduce emissions and report progress under common standards. ⁷  The EU Covenant of Mayors had been established in 2008 by the European Commission to encourage local governments to adopt energy and emissions policies aligned with EU climate objectives. It continues to exist and function as a Regional Covenant. ⁸

Activities

The Global Covenant of Mayors for Climate and Energy (GCoM)’s activities center on facilitating the implementation of certain climate-related policies that are funded and maintaining a standardized, global reporting system. In order to facilitate policy, it offers technical assistance, funding guidance, and piloting programs. It presents the plans and reported data of those cities as evidence that national governments and financial institutions should give cities more funding, authority, and implementation support. ⁹

GCoM builds its membership through Regional Covenants, which it says recruit cities, oversee technical assistance, and put its reporting framework into use across regions. Cities join by submitting a signed commitment letter. After joining, they enter a planning process in which they are expected to measure emissions, assess climate risks, set targets, adopt Climate Action Plans, and report progress within three years. ⁶

The Covenant’s Common Reporting Framework standardizes what participating cities report, including emissions, climate risks, vulnerabilities, plans, and progress. The reported data are consolidated on GCoM’s website and shared with the United Nations Global Climate Action platform. GCoM’s Data4Cities initiative uses that data to produce arguments for more climate planning and investment in cities. ^{3 10}

GCoM requires participating cities to adopt minimum climate targets and to implement Climate Action Plans that will achieve those targets. ³   As cities develop those plans, GCoM provides guidance and tools that can affect how they design policies, estimate costs, and assess feasibility. It provides cities assistance in connecting with, and writing investible proposals for, public funders, development banks, and private investors. ^{11 12}

Thereafter, the city must regularly update the Covenant. The cities are to publicly track and report progress toward the climate-action-plan commitments, report implementation status for each action, and update/resubmit the plan when significant changes occur. ³

GCoM calls for city climate plans to be incorporated into national climate pledges and for cities to receive more funding, authority, and technical support to carry them out. Under a program named Coalition for High Ambition Multilevel Partnerships (CHAMP), GCoM asks national governments to consult with subnational governments while developing and implementing Nationally Determined Contributions, the national climate pledges submitted under the Paris Agreement. Its 2025 impact report called for national governments to shift financial and technical resources to cities, co-create policy frameworks with local authorities, and have development banks and financial institutions expand access to funding and project preparation support. ^{9 13}

Influence in the US

According to the Global Covenant of Mayors for Climate and Energy (GCoM)’s website, 188 cities and regions in the US have committed to the covenant, representing 80 million people. ¹⁴  This includes twenty of the twenty-five largest cities in the US. ¹⁵  As of January 2025, GCoM USA recognized 68 cities and regions as “compliant” for implementing Climate Action Plans. ¹⁶

Those Climate Action Plans must reach a minimum target “at least as ambitious as their country’s “Nationally Determined Contributions,” a measure implemented in the UN Paris Agreement. In 2024, the Biden Administration set an economy-wide target of reducing net greenhouse gas emissions by 61-66% by 2035. While the Trump Administration withdrew from the Paris Agreement in 2025, it is unclear whether that NDC remains the minimum target for GCoM US cities. ¹⁷

A 2026 Pelican Institute for Public Policy report described New Orleans as extensively engaged with Bloomberg-backed climate initiatives: GCoM, American Cities Climate Challenge, Renewable Energy Laboratory, C40 Cities, and Youth Climate Action Fund. This lead to the city’s December 2022 Climate Action Plan, which set targets of net-zero emissions by 2050, 100 percent clean electricity by 2035, and 75 percent no-or-low emission vehicles in the city fleet by 2035. The report describes how the assistance these programs offer embeds fellows into local governments: “[t]hese fellows bring expertise and capacity that cash-strapped governments welcome, but they also bring a predetermined policy agenda.” ¹⁸

Regional/National Covenants of Mayors work through or with various partners. GCoM US describes itself as a collaboration among ICLEI USA, CDP, USDN, and C40, with financial support from the European Union. ¹⁹

Europe and East Asia

The largest share of committed subnational governments are in the European Union and Western Europe: 11,114 municipalities, representing 278 million people. ²⁰  While most, if not all, large cities in the region participate, the density of participating localities does vary. For example, 554 localities participate out of 565 total in Belgium. Others have fewer; in metropolitan France, for example, 199 subnational governments out of 34,900 possible participate in GCoM. ^{21 22}

In East Asia, 88 localities participate, representing 82 million people. All but seven are located in South Korea and Japan. No cities in China have made commitments, other than Hong Kong. While four Taiwanese cities participate, the East Asia page is formatted differently than other region pages in order to not name Taiwan. ²³  

Leadership

Michael Bloomberg co-chairs the board for the Global Covenant of Mayors for Climate and Energy (GCoM) with Teresa Ribera, a European Commissioner from the Spanish Socialist Worker’s Party. The Global Ambassador of GCoM is Anne Hidalgo, former Socialist Party Mayor of Paris, France. ^{24 25 26}

Funding

The Global Covenant of Mayors for Climate and Energy (GCoM) is primarily funded by the European Commission and Bloomberg Philanthropies, as outlined in its charter. ²⁷  In 2017, the World Bank partnered with GCoM to provide $4.5 billion in loans directly to participating cities to fund their local Climate Action Plans. ²⁸

Bloomberg Philanthropies announced it would direct an additional $168 million to “subnational climate leadership,” largely C40 and GCoM. The press release said the commitment built on more than $770 million Bloomberg Philanthropies had already directed to “advance local climate progress.” It is unclear what portion of this funding went to GCoM or what portion of the planned funding will. The last public filing of the Bloomberg Family Foundation with a grant earmarked explicitly for GCoM is from fiscal year 2017: a $9.5 million grant to the European Climate Foundation. ^{29 30}

The European Commission spends approximately €2 million annually on the core administrative functions of the Covenant. This is supplemented by fluctuating, multi-year regional development grants to expand GCoM’s footprint. For example, the German International Cooperation Agency (GIZ) distributed €5.2 million in EU-funds to support GCoM in the US between 2021-2025. ^{31 32}