Over the next generation or two, humanity will need to rethink its cities so as to make them carbon neutral. Buildings will need to produce as much energy as they consume. Vehicles will need to run on fuels such as electricity or hydrogen that are created in ways that don’t produce carbon emissions directly or indirectly. Lifestyles will need to change so as to greatly reduce our personal carbon footprints. We have as of yet little sense of the magnitude of these changes. There are relatively few examples of sustainable communities to guide us. What would life be like in such a place? How might changes in personal lifestyles and built form evolve synergistically? What visions of the carbon-neutral city could help motivate us and our peers to speed up the process of change?

Stephen Wheeler asks: What would life be like in a carbon-neutral world?

Juan Palop-Casado answers:

Besides the classic images of electric cars, solar panels and people cycling, I find it hard to envisage what life would be like in a carbon-neutral city. However I have no doubt about the dramatic changes that a carbon-neutral culture will bring about in the ways we live and work. One of the most important challenges will be the realignment of our personal and professional relationships with the places we live in, and most particularly with their natural and environmental characteristics and dynamics. In the absence of a clear-cut picture of how things would be, I would like to react to this challenging question with four hypotheses based upon a specific environmental condition: “good weather”.

Hypothesis One: We will live in a city twinned with other, foreign cities based on their shared, subtropical (climate) identities.

Two strips that run around the planet concentrate the cities with the best weather on the globe. This geography of “good weather” also concentrates the largest amount of hours of sunshine and is of great ecological potential. The two strips cross four continents and are home to a wide range of nationalities, cultures and cities, including San Diego (USA), Las Palmas de Gran Canaria (Spain), Casablanca (Morocco), Shanghai (China), Brisbane (Australia), Cape Town (South Africa) and Sao Paulo (Brazil): a trans-national geography of subtropical bio-regions with similar climates and vegetation. In the context of a carbon-neutral civilization, we would like to speculate that all these cities and their citizens will be twinned—apart from by their national and cultural identities—by their shared ecological context.

Hypothesis Two: A shared goal of carbon neutrality will make subtropical cities cooperate, the world over.

Carbon-neutral mandates force cities to be aware of their local and environmental dynamics. Subtropical cities, with their shared ecological substrates, also share common opportunities and challenges. The amount of hours of sunshine, the high rates of green production, their waterfront locations and pleasant temperatures all year round are features they have in common and on which they can work together. Given their common goals and similar environmental conditions, collaboration amongst them would seem to be a natural option. They can share a wide range of information, practices and technologies relating to desalination methods, seafront development strategies, photovoltaic technology development, green roof integration, bio-climatic urban codes, off-grid solutions, permaculture techniques and so on. Out of this global exchange between subtropical cities, the geopolitics of “good weather” will become consolidated.

Hypothesis 3: A very competitive, low-carbon, exportation-importation loop will help to enhance urban life in southern European cities.

In a context of high taxes for transportation emissions, close-proximity trade will become more competitive. This could help to intensify North-South trade within the same region, state, union or continent. For instance, southern regions and cities can export fresh fruit, solar power and algae-based biomass. Northern cities can respond with electric cars and tourism. This closed trade loop based on a commercial activity with low carbon emissions could help to contribute towards urban prosperity in some of the hardest-hit southern cities.

Hypothesis 4: We, at LPA, must design tourist cities capable of compensating for the carbon emissions of visitors and transport them back home with zero emissions.

The UK and Germany are the main countries sending tourists to the South. They are also social cultures with commitments in the fields of sustainability and green deals. Since sea and air transport are presumably to be the last sectors where carbon dependence can be avoided, tourist trips are irremediably loaded with regret. Tourist destinations such as the Canary Islands must resolve this contradiction. The solution consists in developing tourist cities able to compensate not only for the 10-day average stay but also for the emissions of the flights. This dilemma will force us to reconsider the way we think and design our cities. The solution will bring another higher level of quality to life in the

Ecological principles, smart technologies and a good climate together will give rise to new subtropical urban prosperity (impossible to envisage as yet) and what we call ‘Advanced Subtropicalism’.

These four hypotheses are part of the vision of what life would be like in a geo-specific, carbon-neutral city. To make this a reality, we need a heady combination of profound place-based (subtropical) knowledge, the development of an ecological awareness and the massive assistance of smart technologies. We bet that out of this alchemist’s brew a truly carbon-neutral subtropical urban life will emerge. In the absence of a more precise vision, we can just provide its conceptualization: ‘Advanced Subtropicalism’.

Team: Juan Palop-Casado with Bentejui Hernández, Isora Macías and Margaret Hart.