'It has to happen in the city. This is where a relatively large number of people feel the effects of climate warming and where greening has a potentially large impact.' That's the view of urban planner Mendel Giezen on making cities sustainable by bringing back nature. He recommends integrated policy: 'Greening doesn't only help with climate adaption, it also has other effects that can support urban planning policy.'
The energy transition
The energy transition entails the transition from the generation of electricity from fossil fuels such as gas, nuclear power and coal to a sustainable and CO2-neutral energy system . In 2019, 8.7% of all energy used in the Netherlands came from sustainable sources. In 2030, that number must be at 27%, and in 2050 the energy production should be almost entirely sustainable.
Mendel Giezen is a university lecturer in sustainable urban development at the University of Amsterdam, where he is conducting research into the energy transition, climate adaption and greening cities. 'More green and nature in the city can help to reduce the heat effect in cities, it benefits biodiversity and increases liveability', says Giezen. We take a stroll with him through the green area alongside Sloterdijk Station, 'a nice example of greening'. Giezen talks about success factors in green projects and his hopes for the sustainable city.
What's the current situation with green in the city?
'We used satellite images to examine how green spaces in Amsterdam have developed over the past 20 years. We saw a large shrinkage of green in the city, a total reduction of 10 percent. This is due to increased density - building more structures in less space - but also due to things such as sports fields that switch from real grass to artificial grass. The green in the city was also increasingly fragmented, so progressively smaller in volume.'
Can we see major differences between cities in terms of green?
'In cities that need to build intensively in limited space due to high housing demand, green is under much more pressure than in cities that don't need to increase their density.' But Giezen also sees differences between various districts. In the expansion districts completed in the 1990s and 2000s, such as IJburg, he says there is strikingly little green. 'The idea there was that you can have water instead of green. So there's plenty of water there, while there's a minimum of green areas. But in the end, water has a different function. Not everyone can enjoy leisure activities on water, have a picnic or go for a quick walk with the dog there.'
Vertical Farming
Food production has a significant impact on global warming, but is also under pressure. Is there enough food for the growing urban population, and is it safe? Vertical Farming, local agriculture with stacked cultivation layers, is often named as a promising solution to reduce demand for urban food production and consumption of scarce resources. Mendel Giezen and his colleague Daniel Petrovics investigated what conditions VF must meet to be truly sustainable, and how it can be scaled up.
