Citizen Involvement wanted: without Citizens’ knowledge?

The streets in the city of Leiden, can be quite beautiful, yet one can’t help but notice that most streets you walk down are barren of any natural greenery. A city that naturally has plenty of rainwater to sustain plant life without the use of artificial watering devices, somehow is devoid of lush greenery. How can this be? The all-encompassing tiling that has been laid out all throughout the city has prevented any plant life from forming naturally. Sure, there may be trees here and there, encircled by bricks, yet thriving gardens, and green walkways are far from being seen.

Let’s take a look at one of Leiden’s most ‘green’ streets : “de groenesteeg” (pictured above): even a street that is named the green street, and is well known for being filled with plant-life, fails to have even one full yard of open earth surface. There may be many pots and other plant carriers, placed on top of the tiled surface: but where is the connection to the earth underneath? In Leiden’s Agenda for 2030 sustainability goals, the municipality clearly states that they’d like to push citizen participation in improving biodiversity within the city. In the past year, they have already introduced subsidies to reimburse and financially support residents with un-tiling their front gardens, replacing the tiles with a green, flora filled garden. Measures have already been taken to encourage resident participation in improving biodiversity in the city. But, how effective have these measures been thus far? I decided to get hands-on and investigate how the residents themselves experience the municipalities attempts at increasing biodiversity, by going through the streets of Leiden city, and knocking on residents’ doorbells. The conversations I had with the locals themselves, opened my eyes to quite a number of things regarding this subject. Not only concerning the resident’s awareness of the cities agenda, but also how the residents themselves feel about biodiversity loss, green spaces, and un-tiling their front gardens.


Let’s begin with the most discouraging insight: none of the residents that I interviewed knew that getting rid of the first 20 cm of tiles in front of their house was legal to do,  let alone that there are subsidies available for un-tiling their front gardens.


One woman around 60, living in the Uiterstegracht, stated that she had asked the government about 10 years ago, if she could un-tile the front of her house, to which they refused due to fear of the roots of plants destabilizing the tiles surrounding it. The municipality clearly had a different agenda 10 years ago, and yet nothing seems to have been done to inform citizens of their new views on what is encouraged, allowed, and no longer condemned. This woman clearly wished to un-tile her front garden, but has never done so due to thinking it was an illegal act.  When I informed her of the subsidies now available to encourage the re-greening of tiled areas, she was astonished. “Now I will definitely get the front of my house un-tiled”, she exclaimed, explaining that it not only is more convenient than having pots in front of her house, but also helps with water retention, preventing run-off. This woman was clearly knowledgeable about sustainability topics, and yet she was completely unaware of any of the municipalities endeavors regarding sustainability. And I dare say: that is truly a shame.quote-the-world-is-not-a-problem-the-problem-is-your-unawareness-rajneesh-56-46-62

Indeed, not one of the residents I interviewed were aware of Leiden’s Sustainability Agenda. The good news is that once I informed them of Leiden’s agenda, all voiced their approval of Leiden’s plan to become more sustainable. So indeed, it seems that residents tend to be pro-sustainable actions when it comes to biodiversity and re-greening the city. The problem is, a lack of knowledge, and surprisingly, I have found, a lack of space for parking bikes. The two residents I interviewed who were pro-biodiversity yet would not un-tile the front of their houses even with help from a subsidy, said that it would deter them from being able to park their bikes in front of their house. Thus I think Leiden has overlooked two important aspects in their plan to encourage citizen involvement regarding biodiversity: the need for the citizens’ awareness, and solutions regarding bike parking.  BerlinBikeShop8x6.jpg


The future in my backyard

A circular economy; an economy where everything is re-cycled and reused, where waste doesn’t exist and where energy comes from renewable sources. Is this type of economy realistic? Companies and municipalities are aiming to be fully ‘sustainable’ in a couple of years. However, is it truly possible within the current system to be fully sustainable?

Six principles of a circular economy:



Yes it is. Two years ago I made a documentary about the closed-loop community at De Ceuvel in Amsterdam Noord. De Ceuvel is a self-sustaining community just 10 minutes away from Central Station. It is a piece of heavily polluted land that is leased by the municipality for ten years to a group of entrepreneurs. The land used to be part of an industrial area and was used for the dissembling of ships.  Now, decades later, this group of creative and social enterprises have thought of a plan to make this waste land into one of the most unique and sustainable urban developments in Europe.


Special purifying plants will clean the heavily polluted soil, so there is no need for expensive soil sanitation techniques. This biomass will again be used to make products and energy. In order to be able to move around without disturbing the plants, they created floating platforms connecting the different studios. The studios are made of old housing boats that would have ended up in the junkyard but are now fully upcycled to brand new working spaces. Moreover, after ten years the (clean) land will be given back to the municipality and the housing boats can be easily moved to a different place.

Furthermore, solar panels are installed to generate energy from the sun. Green roofs and water collection systems are introduced to collect, purify and store the rainwater. Moreover, it is a platform for experimenting with new technologies for more sustainable solutions. So yes, this experiment shows us that it is possible to be self-sufficient and working towards a circular economy.


There are plenty of examples of small scale projects that are (close to) self-sufficient and are operating within the ideas of a circular economy. However, bigger entities such as the municipality of Leiden are also saying they want to take this step. My question is how far does the municipality want to go in becoming more sustainable? Are they willing to move away from current techniques and invest in more sustainable ways of operating? I state that it is possible to create these kinds of communities on a bigger scale, but we should move away from traditional systems and ideas. We should look at these innovative small scale projects and see what factors bigger entities can get from them.

How possible do you think this is? What struggles will they encounter compared to smaller projects?

To get some inspiration and see how De Ceuvel was actually build up, check out the documentary I made over here:

Business, government and nature: an impossible triangle?

How can businesses be more sustainable? Not only we as students are asking this question, this is a challenge the Dutch government and businesses themselves are facing. Even if the motivation is there to create a more sustainable business, it still hard to implement this. Last December I was part of a working conference about sustainable business. This conference was organized by the Dutch government especially for industries, municipalities and other interested parties and specifically focused on Natural Capital (Natuurlijk Kapitaal).

Natural Capital explained by the IUNCS Director General

The concept: Natural Capital

Natural Capital makes the translation of Ecosystem Services towards businesses and other users of nature. Ecosystem services are natural services like provisioning of food and material, regulating systems like climate control, supporting services like water cycling and cultural services like the enjoyment of nature in general. The idea is that businesses and other users are aware of this natural capital and use it in a sustainable way. However it is still a very vague and complex concept. This working conference brings businesses, innovators and policy makers together to bring this concept of Natural Capital into practice.

Econosystem Services scheme:

The role of the government

What I found most striking during the conference was what the Dutch government saw as their responsibility to work toward a sustainable business and integrate Natural Capital. Although the government is responsible for making regulations, the government relies on the power of the free market concept. The government is trying to provide services to stimulate sustainable business and the use of Natural Capital, and tries to avoid rules to impose this principle. For example, on websites like businesses can have free advice what Natural Capital means for them. But how industries implement these advice is up to them.

Green Deal

One of the biggest initiatives on how the Dutch government tries to stimulate sustainable businesses are Green Deals. Green deals try to work towards a circular economy by bringing different companies and interested together and tries to take away regulation barriers that hold these developments. A simple example of a Green Deal: when a fishing boat also catches plastic waste in their fishing nets they can collect it and bring it to a recycling company that can make new plastics out of it. This way the ocean stays cleaner and more plastic is being recycled. The Dutch government can help realizing this green initiative with the right regulations and bringing companies together.

Green Deals explained (in Dutch)

During the conference the Dutch Government was really reflection upon themselves. One of the discussions was also if “Different interpretations of laws and regulations are the biggest obstacle for companies to investment in nature and biodiversity”. Too many regulations can make it hard for a business to function and still be sustainable. On the special website the Dutch government try to create some order and give answers.

In the end was a very interesting day to see how businesses and governments try to work together to bring Natural Capital and sustainable development into practice. But we have release that it is a very complicated matter to stimulate and work together towards a more sustainable world.

For more information about the working conference in its result, take a look at:


Green roofs to make Leiden future-proof!

If we look at climate adaptation of the city of Leiden, the main goal is not to fight nature, but to work together with it. While climate is changing, life in the city changes as well. The more extreme weather causes floods, droughts, higher and lower temperatures and the city cannot always handle this. That is why it is necessary for the city of Leiden to adapt to the climate. One way to do this are green roofs. If you do not know what a green roof is, watch this video to know all the basics.

Green roofs can solve a lot of problems that climate change brings. Green roofs absorb water during heavy rainfall, so that sewers do not overflow. Green roofs keep the inhabitants cool during the hot summer and most of all, it keeps people dry. Also green roofs can provide a habitat for wildlife to increase biodiversity and it can increase the air quality in cities (Oberndorfer et al. 2007). Green roofs mean less consumption of energy because it keeps you warmer in the winter and cooler in the summers.

Green roofs will become also more economically attractive in the future. Now a green roof is in comparison with a traditional roof 10-14% more expensive at a life span of sixty years. If the climate keeps changing and extreme weather will occur, the green roofs will become more and more attractive to prevent flooding and extreme heat in cities because of saving money on energy consumption and other techniques to prevent flooding (Castleton et al. 2010). There is an initiative in Leiden to get more green roofs. It is called Groene Daken Leiden and helps citizens to get subsidies for green roofs. It is based on an initiative of Amsterdam and it is making great progress. If you want more green roofs in your neighborhood you can ask them for help to get subsidy. Then you can help Leiden to adapt to the future in a more sustainable way for only a small fee. In the picture below you can see a project they did at the Boerhaavelaan in Leiden.


The benefits of green roofs are endless for the environment and for the people living under them. Green roofs are a great way to get more green and plants in the city and increases the aesthetic value of neighborhoods. Green roofs are also a great method to reduce noises and living in a busy city this can be of great value! Green roofs does not demand a lot of maintenance. Only in periods of drought is it necessary to water your roof, but even a dryer roof will keep all it functionality and benefits (Getter & Rowe 2006).

Leiden is a very dense build city and has a strong heat island effect. This means the temperature in the city is on average 3 degrees Celsius higher than in rural areas. With rising temperatures because of climate change this can cause a lot of problems for the city, such as droughts and higher mortality rates during heat waves. If we want to keep the city a nice place to live, things have to change for future generations. Green roofs can provide a solution to make Leiden future-proof!

Nuclear Energy as Renewable Energy

When you would ask people on the street what renewable energy is, most answers will at least include wind, water and solar energy. There are more options to produce energy in an environmental friendly way like biomass energy, tidal energy and geothermal energy, but people are less aware of these possibilities due to a lesser impact in their daily lives. There might be another form of renewable energy; nuclear energy. What is nuclear energy and how can it be defined as renewable energy?

Nuclear power plant

Nuclear energy generation comprises of two processes, fission and fusion. Firstly for the fission process uranium or plutonium is hit with neutrons to split the atom into two fission products. Becfission-how-nuclear-energy-worksause multiple neutrons are used, they can hit multiple atoms, creating a chain reaction with more heat. This heat is then used to generate electricity. This fission process is used in almost all nuclear power plants. The fusion process basically combines two small atoms like hydrogen and helium into one larger and heavier atom, still creating heat when the atoms interact. The process thereafter is still in a research stage but promises an energy production process that is subject to less depletion, less proliferation and less radioactivity (What is Nuclear 2015 (fission/fusion animation)).


Carbon emissions: nuclear power only emits 4% of gas energy production.

The main nuclear process is deemed to have a low carbon emission. When renewable energy is used to lower the carbon emission worldwide, we should change to nuclear energy immediately. Nuclear power produces even less indirect carbon emission than solar and wind power, mostly due to the production of generating machines (turbines, solar panels) (Hitachi 2010).

Another positive aspect is the amount of energy produced within a certain period or with a specified amount of resources: uranium can provide a lot more energy than other fossil fueled energy production processes.


There is one major issue with the renewability of nuclear energy: uranium is categorized under fossil resources and thus not as renewable as e.g. wind or solar energy. But the possibilities of this uranium are being researched. Similarly to oil retrieval, uranium is available in different grades of accessibility; e.g. deep in the earth or deep in the sea. The research also focuses on the possibility of recycling uranium or increasing productivity. When this research develops, the longevity of uranium is increasing towards the renewable energy category. Another issue with nuclear energy is the byproduct of nuclear waste; radio-active materials that remain pollutants for a very long time (Chowdhury 2012). Renewability can only be improved when this waste is addressed, but scientist are working on this problem! As mentioned before, the fusion process produces less to no radio-active byproduct.

The answer to the question “is nuclear energy renewable energy?” is dependent on the developments in research in this field. Nuclear energy is at least close to carbon neutral, has a high productivity, and in the future these advantages can be enhanced with less to no waste and less dependency on a finite resource. The current process is not that renewable and thus investments in the fusion process development can provide a great step for sustainable energy production.


Lost Treasures

They used to be the pride and joy of many a farmer. Family gardens were plain without them and innumerable children have enjoyed their benefits: Orchards! And while J.K. Rowlings’ Weasley family still owns one, their numbers are dwindling even in the classic gardening nation, the United Kingdom, despite their enormous importance for regional and national biodiversity. In 2004 Natural England  set up a program¹ to research the extent, distribution, biodiversity and management of traditional orchards in England. The results were published in 2009. In six different orchards growing different fruits, the researchers and volunteers found almost 900 lichens, mosses and invertebrate species, some of them on the red list of endangered species. A similar study² taking place in 2004 on 2.2ha of orchards, found a staggering 1,800 species across the plant, fungi and animal kingdoms. This goes to show that orchards are hotspots for biodiversity, capable of supporting a wide range of wildlife, including BAP priority habitats and species as well as an array of nationally rare and scarce species.


source: Pippa Palmar,

But what is the reason for the dwindling of traditional family kept orchards? Apart from the obvious urbanisation eating up the garden space have we simply become too lazy? Working as a gardener in private gardens I keep hearing the same litany: Too much work, too little time, no space. Contrary to popular belief orchards can be very low in their maintenance. Indeed the less interference the more biodiversity can develop in it. It is not necessary to plant a single variety or even species of fruit. The more the merrier and divers! If space is your only problem, consider growing your fruit trees in espalier style! By pruning and training the trees to a two-dimensional shape they can be planted along walls or fences or even form a living-hedge themselves! Where there is a will there is a way so nothing needs to stand between you and your apple tree!



In Germany the orchard tradition is also well known and applied under the term ‘Streuobstwiese’ (falling-fruit-meadow). Even more natural and completely devoid of chemical pest control or fertilisers they play a vital role in preserving traditional fruit tree breeds³. While the official market offers around 60 types of apples, there are more than 3000 different species in Europe alone. Orchards are valuable reservoirs for the diversity of apple species and preservation of the gene-pool and excellent source of fresh and ecologic fruit. Since in Germany too, the gardens are getting smaller and the orchards fewer, municipalities frequently plant orchards on public grounds that need to be clear of buildings due to the city planning regulations.

This concept could be applied in the Netherlands as well. Plenty of space like the one next to our very own university building is left fallow, but no one ever seems to be thinking of creating an orchard. Why not plant a handful of fruit trees, leave a meadow under them and a couple of benches? Which student wouldn’t like some delightful, pesticide-free fruits free of charge? Relishing a study break under the apple tree would be so much more enjoyable than just standing on a dismal parking lot in front of the building wouldn’t it? Supporting biodiversity in all its aspects in front of a building in which students study biology and sustainable development seems like a reasonable thing to do. Reviving traditional Dutch breeds would enhance the local biodiversity, aesthetic appeal of the area and culinary benefits for students, staff and passerbys. We need to retrace our botanical heritage if we want to benefit in the future!


source: private photography

Orchards- a lost treasure worth bringing back!

  1. Natural England Research Report NERR025:
  2. The Traditional British Orchard:

Let’s Fly to Sustainable Mobility

Transport is one of the biggest and fastest growing sources of CO2 emissions in the world. Transport runs for 90% on fossil fuels which makes it very polluting. A solution for this may be to look for other kinds of energy to fuel transport. We can already drive an electric car or travel by electric busses. For flying however we still use fossil oil. In this blog I will explore options for aviation that are in line with sustainable mobility. In the future we may even be using electric airplanes!

In many ways travelling by airplane is very attractive to people. It is comfortable, relatively cheap and extremely fast. Commercial aviation has become essential in the world economic system. However, how convenient it may be, aviation is also a very polluting source of transport. Second to diesel motor cars, aviation is the most polluting transportation  for passengers and freight. There are at least seven times more greenhouse gasses emitted when you fly in stead of take the train to the same destination. Aviation also causes pollution to a local and regional level. At a local level noise pollution can be a major disadvantage. All in all aviation is at the moment no where near sustainable mobility.

However, there is hope! First of all we can try to change peoples flying habits. By less flying, fewer emissions would be emitted and therefore pollution would be limited. However, this does not make flying on itself more sustainable. To become more sustainable, technological changes are necessary for the flying sector. Examples of technological changes are building more fuel efficient aircrafts, operating more efficiently or changing the fuel source. A radical improvement would be to use a different kind of fuel. Many experiments have been successfully done with biodiesel and carbon-neutral fuels.

Since the 1970s experiments with electric aircrafts have been conducted. The Airbus Group developt an all electric aircraft. In this video you see the test flight in which the E-fan crossed the English Channel, solely on electric power. Airbus group now plans to further develop this airplane and market different two different versions of it. There will be one that is solely powered by batteries and a hybrid version that could improve endurance up to 4 hours.

Even better endurance can be found with the aircrafts that are powered by photovoltaic cells, like the Solar Impulse. The solar impulse is a solar-powered aircraft. the Solar Impulse 2 could fly for 5 consecutive days without the use of any fuel! No other aircraft has ever done this before. This type of aircraft can even fly during the night. In February 2016 new exciting test flights will start.

There still is still research to be done and there are a lot of problems to be solved, before we can start using sustainable aircrafts. However, these examples show that sustainable aviation is possible! We have a start, now we must further develop our technologies. Although I do acknowledge that we are not there yet, I do believe there is hope for sustainable aviation in the future. Aviation is a major part of transport and should be green.