Common Questions

What is the Compact of Mayors?

The Compact of Mayors is the world’s largest cooperative effort among mayors and city officials to pledge to reduce greenhouse gas emissions, track progress and prepare for the impacts of climate change. Compact cities are supported by city networks and “endorsing partners” in this significant undertaking.

Download the full guide to compliance for the Compact of Mayors.

Why was the Compact of Mayors launched?

With 70% of the world’s greenhouse gas emissions coming from urban areas, the enormous work being done locally to address climate change is more important than ever. Local leaders are seizing this opportunity by making ambitious commitments to fight and adapt to climate change, and the Compact of Mayors is providing a space to publicly recognize this. More specifically, the Compact:

  • Enables recognition of new and existing city-level commitments by making annual reporting data publicly available. Existing initiatives include the US Mayors Climate Protection Agreement (2005), the EU Covenant of Mayors (2008), Making Cities Resilient Campaign (2010), the Global Cities Covenant on Climate – the Mexico City Pact (2010), and the Durban Adaptation Charter (2011); the US Mayors National Climate Action Agenda (2014), among others;
  • Establishes a robust and transparent data collection standard for local action.

What is the purpose of the Compact of Mayors?

The Compact consolidates cities’ climate actions through consistent and transparent public reporting of greenhouse gas data. This data-driven platform, which is similar to the one used by nations as they create national climate plans, will help direct resources and policies that better support and accelerate local climate actions. This, in turn, will drive and showcase innovative city level climate action, and inspire change at the global level. More specifically, the Compact:

  • Commits cities to common reporting processes that allow for consistent and reliable assessment of progress towards meeting their GHG targets;
  • Creates an evidence base of the greenhouse gas impact of city action to enable capital flows into cities to support taking further action and to be held responsible for that action and the associated investments;
  • Demonstrates the commitment of city governments to contribute positively towards more ambitious, transparent, and credible national climate targets by voluntarily agreeing to meet standards similar to those followed by national governments; and
  • Encourages national governments to actively support additional city action by recognizing local commitments, establishing more enabling policy environments, and directing resources to cities to limit any further increase in global warming and to appropriately resource both mitigation and adaptation of local climate action.

Does the Compact address both climate change mitigation and adaptation?

Yes, the Compact asks cities to voluntarily publish and track commitments, targets and actions for both greenhouse gas emissions mitigation and assessing and adapting to climate risks.

How can a city take part?

Click here to find out how to commit to the Compact, or email You can also download the full guide to compliance for the Compact of Mayors.

What are the Compact compliance requirements?

All cities and towns of any size may take part in the Compact of Mayors. Upon making an initial pledge to the Compact, cities will receive an official “Compact of Mayors” seal, which may then be displayed publicly on web and print materials. Cities then have up to three years to meet a series of requirements to fully comply with the Compact, including greenhouse gas (GHG) measurement and target setting. This culminates in creating a full climate action and adaptation plan. More details on compliance requirements are available for download here.

What if my city has already met some or all the requirements towards being compliant?

The Compact welcomes all cities that have already taken steps towards being compliant. The Compact of Mayors has been designed to recognize that each city may have a different starting point on this pathway, and may progress to full compliance at different rates. Each of these stages present significant accomplishments and should be recognized accordingly. If your city has already completed some or all of the requirements, you will receive a “Compact of Mayors” seal and relevant badge to demonstrate your status. You can use this badge to demonstrate your leadership and commitment on marketing materials as well as social media and web channels.

How can I remain "Compact Compliant"?

Cities remain compliant with the Compact by regularly reporting on their progress through the standard reporting platforms, carbonn Climate Registry or CDP. This requires regularly updating their greenhouse gas inventories, documenting their emissions reductions and reporting on mitigation and adaptation actions.

Are there resources, trainings or technical assistance to help cities become Compact Compliant?

Yes, the city networks C40, ICLEI and UCLG will be offering a series of training webinars to introduce the Compact of Mayors and compliance requirements. Compact support staff members are also available to respond to individual questions on an as-needed basis. Tools and further training materials are also under development and are available here.  Please contact us at with any questions.

What will be announced at the Paris Climate Summit (UNFCCC COP21) in December 2015?

The Compact aims to have hundreds of cities showcase their commitment by the COP 21 in December, demonstrating to nations that cities and local governments are crucial partners in a global climate solution now and in the future.