2019•03•25     Bonn

© UNICEF / Pirozzi

Op-ed by Dr. Simone Sandholz, Senior Scientist at UNU-EHS

“The Sun, the Earth and the Weather” sounds like a movie title, but it is actually this year’s World Meteorological Day’s theme and three of the greatest challenges – but also opportunities – for urban areas.

The Sun

While climate change-induced heatwaves pose a particular risk for urban areas and their inhabitants, as temperatures can be particularly high due to densely built-up areas with little ventilation and few green spaces, solar energy is on the rise. Various cities have accessed their potential to install photovoltaics on rooftops to promote the use of renewable energies.

An example is Brazil. Brazil has abundant solar resources that are largely underutilized, as the average daily global horizontal solar irradiation is considerably higher than in many European countries (Germany, France and Spain to name a few). Despite the country being rich in renewable resources (they account for more than 70% of the energy production in 2014), Brazil is facing enormous challenges with its electricity supply, and solar energy is a viable alternative to the diversification of the Brazilian energy matrix.

At UN Climate Conference (COP 21), Brazil signed an international commitment aiming to “expand the domestic use of non-fossil energy sources to at least 23% by 2030, including by increasing use of wind, biomass and solar energy.” Building up on this important commitment, the government established tax benefits for renewables including state VAT exempts for certain equipment for wind and solar energy projects, which are valid until 2021. In addition, the Brazilian National Bank for Economic and Social Development (BNDES) supports the development and implementation of wind and solar energy projects through periodic financial programmes. In parallel a number of Brazilian cities have come up with detailed assessments on solar energy potential for rooftops, among others in Rio de Janeiro.

Nevertheless, these types of incentives are still not enough, as most of the projects installed “use autonomous systems and focus on isolated houses, far from the distribution networks”.

The Earth

Since soil sealing adds to urban heat, reduces water runoff thereby contributing to urban flooding, the values of green spaces are increasingly being recognized, and urban gardening is practiced by 800 million people worldwide. Just to have an idea, an area of just one square metre can provide 20 kg of food per year! As a result, the growth of farms and community gardens in urban areas, improves the ability of community members to cope with social and environmental change.

A profound change of the global food and agriculture system is needed if we are to achieve the Sustainable Development Goal of Zero Hunger and therefore “nourish the 815 million people who are hungry today and the additional 2 billion people expected to be undernourished by 2050.” In addition, urban agriculture could also contribute to achieving other sustainable development goals and targets, as it could improve social and economic conditions of the most vulnerable living in urban and semi-urban areas, and favors both social inclusion and reduction of gender inequalities. How? The most marginalized people spend up to 85 per cent of their income on food purchase and 65 per cent of urban farmers are women! Urban agriculture also improves air quality, and supports reducing the environmental impact related to both food transport and storage.

Urban green areas also contribute to local climate and disaster risk reduction, e.g. by decelerating water runoff and thus reducing flood peaks. can support climate change adaptation and disaster risk reduction, not only in rural areas but also in cities.

The Weather

Extreme weather events will keep on increasing and become more unpredictable with climate change. Critical infrastructure such as power or water supply is at increasing risk from natural hazards and is being constantly damaged. Minimizing disruption to these networks should form part of any strategy to increase urban resilience.

The resilience of critical infrastructure in the context of natural hazards and disasters is equally a social and urban concern, as disruptions often have particularly severe impact on the weakest, most vulnerable and resource-poor members of society. Experiences from past events have shown limited capacities of households to sustain themselves if regular infrastructure supplies are damaged.

In 2017, hurricanes Irma and Maria struck Puerto Rico and uprooted most of the island’s power grid, resulting in a major power outage and leaving millions without electricity, water, telecommunications and transportation systems. Months after the event, the death toll rose form initially 64 to as many as 2,957 who died in the six months after the event as a result of poor healthcare provision and a lack of electricity and clean water.

Becoming more resilient and preparing for the next storm is a challenge, but Puerto Rico is trying to tackle it. For example, if reconstruction facilities like hospitals turn to own solar power and if micro grids become more resilient.

As a conclusion all three important elements are closely intertwined and key for a successful transformation of urban areas towards a more sustainable future.