Cities can lead a green revolution after Covid. In Barcelona, we're showing how.

From non-polluting transport to sustainable industries, urban areas are perfect for testing radical solutions to global problems.

The pandemic will leave behind a very different world from that of a year ago. Thousands of people have died; entire industries have been brought to the brink; welfare states have been shaken. In the coming years, the major challenge facing all public leaders will be charting a path of recovery through the devastating human, social and economic marks that Covid-19 has left on our societies.

But rather than redoubling on the fragile world of the pre-pandemic age, we should be taking advantage of this moment to build one that is more just, balanced and sustainable.

Cities will play a key role in this process. Barcelona and its metropolitan area want to lead the response to one of the toughest situations that humanity has faced in modern times. Achieving this will mean tackling two interrelated challenges. We need to continue the fight against the climate crisis, spurred by the European Green Deal. And we will need to boost the post-Covid economy through green technologies, sustainable industry and transport.

Although these are global issues, change can begin in urban centres. Cities can play a pivotal role in transitioning energy use away from fossil fuels. They can adopt non-polluting modes of transport and build green public spaces that absorb carbon dioxide and release oxygen.

Barcelona has long been committed to these goals. Over the next decade, our “superblock” plan will transform the entire central grid of the city into a greener, pedestrian-friendly and almost car-free area. We’ll extend this model to the entirety of the Eixample district, first designed in the late 19th century by the urban planner Ildefons Cerdà, who envisioned an integrated, modernist extension to Barcelona based around a grid system, providing new public spaces for mobility and recreation.

The Covid-19 crisis has reminded us all of the importance of scientific advances. Progress in areas such as vaccines and testing are what will provide the exit route from this pandemic. Cities can play a role in nurturing science, technology and digital industries, something Barcelona has been doing for years, through public policies aimed at attracting talent and building new infrastructures.

Our city is home to the MareNostrum 5 European supercomputer, for example. Built by the Barcelona Supercomputing Center, this new type of computer can be used in areas such as human genome research, the design of new drugs and weather forecasting. And as mayor of Barcelona, I’m currently reviewing the proposal that the Spanish government has made to the European Centre for Medium-Range Weather Forecasts to make Barcelona the headquarters of this important institution, whose forecasting skills and environmental expertise are key to the fight against climate breakdown.

Our aim is to become the major scientific and cultural capital of the Mediterranean, driving Europe’s transition towards a green and circular economy. And we can do so through the innovative, courageous and resourceful spirit that has long characterised our city, working to improve the quality of life of our neighbours, and ensuring that our post-pandemic society leaves nobody behind.

Yet while cities can be leaders on these issues, it’s clear that they cannot – and should not – be doing this alone. Different levels of government should be working together with both public and private actors if we are going to be successful in the fight against the climate crisis and in building an equitable, green economic recovery. These are global challenges, and they will require international solutions. But cities are a good place to start.

• Ada Colau is the mayor of Barcelona

5 December 2020

The Guardian