Cities are pivotal in the global quest for climate neutrality, yet implementation of climate actions often lags behind their ambitions. A recent article published in Nature and Urban Sustainability distils recommendations based on the experience of over 362 cities eligible under the EU Mission 100 Climate-Neutral and Smart Cities, over 13,000 cities from the Global Covenant of Mayors, and beyond.
Giulia Ulpiani, lead author of the article, underlined:
“These 5 practical recommendations can be used by cities as a checklist to unlock their full potential in reaching net-zero emissions. Every line of the manuscript contains a key message, the voice of many cities, the evidence from multiple angles and disciplines that we have the duty and honour to share. As we say in our paper, "the moment is ripe to empower cities, drawing key lessons from the experience of cities worldwide in climate action". It’s a scientific storytelling, easy to read, easy to relate to, easy to get inspired from. We hope it will simply motivate, unite, and mobilise many to join the quest for a climate-neutral future with cities as early movers, innovation hubs, and trendsetters”.
Cities are indispensable actors in the global effort to achieve climate neutrality, yet a significant gap persists between their ambitious climate targets and the practical implementation of actions.
According to a recent report, worldwide, cities are responsible for a substantial share of greenhouse gas (GHG) emissions, accounting for 67 to 72% in 2020. While net-zero commitments have proliferated, the current rate of emissions reduction (1.6% per year) falls short of the necessary 2.7% globally. Furthermore, only a small fraction (7%) of existing urban targets are aligned with scenarios that limit global warming to 1.5C.
Achieving climate neutrality—a holistic, integrated state where the balance of positive and negative emissions across all sectors, gases, and scopes is zero—requires cities to navigate unprecedented complexity and systemic changes.
This perspective proposes five practical recommendations grounded in the experience of a large sample of cities worldwide to help bridge the ambition-implementation gap. These recommendations are centred on a triple 'inter' synergy: integrity (ethical and moral foundations), interaction (consultative process and governance), and integration (holistic nature of the transition).
1. Strive for Comprehensiveness, Transparency, and Integrity
Effective climate action begins with a robust and honest accounting of emissions. This recommendation focuses on enhancing the integrity of a city's net-zero pledge through accurate, comprehensive, and up-to-date GHG emission inventories.
- Improve Emissions Accounting: Cities should insource the development of their emissions inventories to fully own the process and develop a strong territorial understanding of emissions origins. They must also empower their technical capabilities with high-quality data, including advanced sensor networks and earth observation, to accurately measure emissions, particularly for hard-to-track Scope 3 emissions and in the Global South.
- Ensure Integrity of Net-Zero Targets: Cities often pursue net-zero targets that rely on mechanisms like carbon sinks (e.g., greening and forestation) to compensate for residual emissions. To uphold legitimacy, cities must transparently disclose the components of these residual emissions, ensuring they result from a dynamic, multidisciplinary analysis rather than disguising politically inconvenient operations. Furthermore, the priority must always be on emission reduction at the source (the "mitigation first principle").
2. Engage in Financial Experimentation and Innovation
Securing the massive capital required for the transition remains a significant hurdle, with many cities lacking the competency to formulate investment strategies or effectively capitalise on available funding.
- Mobilise Diverse Capital: Cities must move beyond conventional financing like property taxes and debt, and explore innovative financing instruments such as energy service companies, green bonds, public-private partnerships, and crowdfunding. These alternatives are relevant across the Global North and South, particularly for the digital transition.
- Integrate Co-benefits: The financial gap can be narrowed by factoring in the efficiency of different technologies and the role of nature-based solutions (NBS). By measuring and monetising the co-benefits of climate action (e.g., improved air quality, public health), cities can attract a wider range of investors and demonstrate how climate neutrality benefits all citizens.
3. Enhance Polycentric Governance, Collaboration, and Collective Ownership
Addressing the complexity of climate neutrality requires a shift toward polycentric governance, which enables multiple, overlapping centres of decision-making and stimulates local experimentation and learning across scales. This strengthens the interaction element of the transition.
- Foster Collaboration: Cities should participate in inter-city networks and Science-Policy-Practice (SPP) partnerships—engaging businesses, academia, and other government levels—to harness epistemic diversity and accelerate the pace of transformation.
- Prioritise Citizen Engagement: Meaningful engagement must center on collective deliberation, where citizens reflect on shared challenges and co-create solutions. An effective strategy requires a clear objective and a defined role (co-creative, decisional, or consultative) for citizens and stakeholders.
4. Use Equity and Inclusion as a Compass for Holistic Action
The transition to climate neutrality must be guided by the principles of equity and justice to prevent negative consequences from disproportionately affecting the most vulnerable.
- Implement a Climate Justice Framework: Policymakers should use the climate justice framework, based on recognitional, distributional, procedural, and intergenerational pillars. This means systematically assessing the social effects of policies to ensure climate action benefits all socioeconomic, age, and gender groups, and actively making the voices of marginalised communities heard in decision-making.
- Prevent Inequities: Addressing issues like renoviction (displacing tenants due to energy efficiency renovations) and ensuring access to public transport for vulnerable communities is crucial, especially when the climate neutrality target is close and requires unprecedented rates of renovation. Some cities are prioritising interventions to improve the quality of life for the most deprived first to mitigate the risks of pauperization and social division.
5. Champion Integrated and Interoperable Urban Planning
A comprehensive and holistic planning approach is essential for the integration of climate goals across all municipal functions.
- Adopt Multi-Sectoral Planning: Cities must adopt comprehensive planning strategies that cohesively consider all sectors (energy, transport, waste, land use, etc.) and goals (GHG reduction, adaptation, liveability). This includes maximising co-benefits, such as combining energy retrofits with seismic resilience and social housing initiatives.
- Foster Territorial Cohesion: Integrated planning must promote urban-rural balance to leverage the strengths of surrounding areas, such as natural carbon sinks and the high potential for renewable energy (e.g., 78% of Europe's photovoltaic, onshore wind, and hydropower potential is rural). Strong urban-rural partnerships are critical for decarbonising supply chains and building regional resilience.
- Embrace Smart City Solutions Responsibly: Digital and smart city solutions can be powerful instruments of integration, but cities must proactively manage risks such as the digital divide and cybersecurity vulnerabilities to ensure an inclusive and secure transformation.
These five recommendations—focused on integrity, interaction, and integration—form a framework for cities to systematically address the most common risks and move from ambition to decisive implementation on their journey to climate neutrality.
Details
- Publication date
- 5 November 2025