Barcelona Metropolis

Cities are vital in tackling the challenges of climate change, not only because of their role in generating emissions but also due to their increased freedom to act in response to geopolitical trends and their capacity for adaptation and innovation. While actions to reduce emissions or adapt to their impacts are essential, these must be combined with an integrated metropolitan vision.

Any article we read about cities and climate change typically begins with similar statistics, which highlight the crucial role cities play in this global battle: they host 55% of the world’s population, and this figure is expected to rise, reaching 68% by 2050.[1] Consequently, cities are responsible for the bulk of greenhouse gas emissions. According to the Intergovernmental Panel on Climate Change (IPCC), around 70% of global emissions come from urban areas, which occupy just 2% of the Earth’s surface.[2]This places cities at the heart of efforts to adapt to and mitigate the effects of climate change.

Local governments are key actors and will play an even more significant role at both the national and global levels, especially in light of the outcome of the US elections and current geopolitical tensions.[3] Cities are already taking the lead in driving climate action by promoting urban climate solutions, influencing international climate discussions and demonstrating innovative strategies. This is possible because cities can act more swiftly, implementing tailored solutions while sidestepping the deadlock that often hampers national and international negotiations.

In this context, many cities have set goals for carbon neutrality, driving initiatives like the promotion of renewable energy, public transportation and energy efficiency in buildings. A case in point is Copenhagen, which aims to reach carbon neutrality by 2025 and had already reduced its emissions by 72% by last year.[4] Many other cities, including Barcelona, have committed to achieving this goal by 2050.

In the Barcelona Metropolitan Region (RMB), 15 out of 164 municipalities declared a climate emergency in 2020. A study conducted by the Barcelona Metropolitan Strategic Plan (PEMB)[5] points out that, despite this declaration, the lack of an integrated metropolitan vision complicates the implementation of effective measures, as each municipality acts independently with different priorities and approaches. This leads to duplicated efforts, lacking coordination, as well as a lack of allocated budgets for these plans, creating inequalities between cities. The lack of collaboration among stakeholders and the absence of mandatory measures limits the overall impact, while cities like Barcelona, L’Hospitalet de Llobregat and Sabadell are better positioned to reach their goals.

Many of these municipalities have also developed local plans to fight climate change. For instance, L’Hospitalet de Llobregat has its own Sustainable Energy Action Plan, as does Cornellà de Llobregat. The Metropolitan Area of Barcelona (AMB) has also created the Climate and Energy Plan 2030[6] which seeks to strengthen and improve coordination with municipalities and other administrations to optimise resources, share knowledge and speed up responses, all while joining efforts in the commitment to climate action.

The most prominent of these plans is Barcelona’s Climate Plan, an integrated strategy to tackle climate change and reduce greenhouse gas emissions in the city. The goal is to transform Barcelona into a more sustainable and resilient city, with a strong focus on improving air quality, increasing renewable energy and promoting clean mobility. The plan also includes measures to help the city adapt to the impacts of climate change, such as rising temperatures and flooding, and promotes energy efficiency in buildings, urban regeneration and the enhancement of biodiversity. Through this roadmap, Barcelona aims to become a global leader in the fight against climate change and achieve carbon neutrality by 2050.

In this article, we will provide examples of how cities can reduce their emissions and adapt to the impacts of climate change.

The transport challenge

The Monitor Públic d’Emissions de Catalunya[7] [Public Emissions Monitor of Catalonia] recently made headlines by revealing that the reduction in greenhouse gas emissions is slowing down. In 2024, emissions decreased by 0.9%, a figure that already indicates a slowdown compared to the more significant 5.4% reduction achieved in 2023.

Looking at the sectors individually, emissions from industry have decreased, particularly in 2023, due to factors such as the drop in natural gas consumption driven by the war in Ukraine. The energy sector has also seen a reduction in emissions, mainly because of the lower use of natural gas in thermal power plants. However, emissions from transport have not fallen in recent years and have remained at levels similar to those of 2022.

On the other hand, extreme weather events, such as intense storms, floods and Mediterranean cyclones, also have a major impact on cities in this region. The Gloria storm in January 2020 was a clear example of how heavy rainfall and strong winds can cause widespread destruction to urban infrastructure. The most recent event, still ongoing, is the 2024 DANA in Valencia, where rainfall reached 230 mm in just 24 hours, causing flooding that led to 224 deaths[12] disrupting transport and the power grid, and resulting in economic losses of 17 billion euros.[13] The World Weather Attribution (WWA), a research centre focused on attribution studies, points out that the rainfall from the DANA flash floods in Valencia was “12% more intense” and “twice as likely” due to climate change.[14]

Cities are already taking steps to address the impacts of climate change, particularly heatwaves and extreme weather events. In Barcelona, for instance,[15] the Pla Director Integral de Sanejament de la Ciutat de Barcelona (PDISBA, Integral Sewerage Master Plan for the City of Barcelona) was approved in 2020, which rethinks the sewage and drainage system to adapt the infrastructure to the effects of climate change. It includes urban drainage systems such as non-paved green areas, improvements to the sewage system and reservoirs that allow for the management of excess water. These actions would be essential across the entire metropolitan region, which will experience impacts similar to those identified in Barcelona.

It is also crucial to invest in raising public awareness and rapid-response plans for such events. As demonstrated by the DANA flash floods in Valencia, preparation and an effective response can help minimise the damage caused by such events.

Cities play a pivotal role in the fight against climate change, but an integrated metropolitan approach is essential to ensure a coordinated and effective response. This will help avoid duplication and ensure that actions reach all communities.

[7] Monitor Públic d’Emissions de Catalunya [Public Emissions Monitor of Catalonia]. monitorco2e.cat

[8] Winkler, L. “The effect of sustainable mobility transition policies on cumulative urban transport emissions and energy demand”. Nature Communications. 2023. via.bcn/gF5t50UZcOx

[9] www.barcelona22.net