Category Archives: Uncategorized

‘Green Your City Competition’

Singapore the ‘Garden City’

Green Your City Competition

Over the past century we witnessed a constant trend, shifting the lives of people increasingly away from rural settings to the urban sphere. Whereas, currently around 54% of the world population lives in cities, this number is expected to rise to a full two-third of the human population (Hawley 2014). In the eyes of the ubiquitous threat that climate change poses not only for the continuation of vital ecosystem services, but for the very livelihood of our cities. It is indispensable prerequisite to adapt our cities in a sustainable fashion in order to be prepared for whatever changes the future might bring. Singapore, also known as the ‘Garden City’ is a prime example of a sustainable city, that has despite its growing population, managed to incorporate various types of biodiversity, such as green roofs, cascading vertical gardens, and many other forms of greenery, into its urban landscape. Singapore sets a benchmark for all cities to strive for, but how can this be achieved if a city has considerably less financial means?

The ‘Green Your City Competition’

The Green Your City Competition brings together citizens, eco-tourism agencies, municipalities, and many other stakeholders in cities all over Europe, in a combined effort to green our cities. How will this be done?

In a close collaboration with an environmentally conscious search machine, such as Ecosia that plants a tree for every search you do, through its ad revenue. By expanding this concept from solely deforested areas to cities, the energetic capacity of our society can be used in a communal effort to restore the biodiversity that has once been lost in our cities.


European Cities that are interested in participating will work in close collaboration with city specific agencies that are willing to put advertisement on the search engine. This could for example been done by eco-tourism agencies that have a high interest in attracting more people to their city. It is then the job of the municipality and environmental agencies to campaign the initiative to its citizens, in order to incorporate a wide-spread use of the ‘green search engine’. Specifically, for this purpose the ‘green search engine’ will be adapted next to its original purpose to a city specific context, in that once the citizens connect to the browser they will have the opportunity to type in the name of their city. This way it will be clear how much of the revenue created in the form of trees, greenwalls, green roofs etc. will be devoted to each city.

Which form will this endeavour take?

The municipality together with its citizens will make a business plan, deciding on the part of the city that need improvement, and in what form this will be done. Thus, depending on the problems the city is facing, they could for example decide to plant more trees in parking spaces, or construct green walls to counter the heat island effect of highly paved areas. Indeed, this can be realized in any way that seems appropriate for the city-specific case. Once enough revenue has been collected the city will receive the money for the assertion of the project. This will be done under close supervision by the ‘Green Your City’ committee to ensure the correct usage of the money. Lastly, the surplus of funds initially aimed on greening related projects ought to be used for the continued maintenance of those newly planted areas.


By mobilizing the energetic society through an incentive of a better living environment, facilitated through the little effort of simply using a new search engine, the cities will not only be able to carry out their vision for a sustainable future, but this will set an incentive for cities all over the world to follow their example.

For further information concerning sustainable search engines, look at:


Work Cited:

Hawley, Kate. 2014. “Transforming Cities For Sustainability: Facts And Figures”. Scidev.Net.



Circular Economy Not Enough

The world is deteriorating in all its aspects. Biodiversity is extremely declining, resources are becoming more scarce, the amounts of plastic in the sea is growing and the climate is changing as never before.

The core of the problem consists of multiple aspects. To begin with there is a lack of knowledge about the cohesion between the ecosystems, air flows and sea streams. The importance of nature and biodiversity is highly underestimated as a result of this absence of knowledge. Second, we are stuck in our own locked in systems in which changing is very difficult. We are stuck in our economy and the power money has over the market. In our society everything turns around money, which results in the majority of the people striving for it as a priority number one. The problem is that nature is not included in the price, which causes many of the several environmental issues of today.  Fortunately, more and more people are realizing this and aiming for a chance. The big question is where to change to? No one really has an answer to this fundamental question. In this short blog I will try to give a small part of the total answer talking about circular economy. I will apply this to an industry area in The Hague where more than 400 business are located.

The idea of a circular economy finds its origin in nature. In nature waste does not exist, everything has a purpose. There is a natural life cycle for everything. With the circular economy, we try to mimic this system by reusing the materials we use for our products. The idea is that we no longer extract new resources but create a material flow instead. In this way we can try to close the circle. The YouTube video below gives a visual representation of this system.

In this model all the resources will be reused and recycled over and over again. However, I see two problems with that.

First does it still not solve the current waste problem that we have. The materials will be reused, but not in such a way that it is part of a natural continues cycle. The products will still not be biodegradable, what means that it is not possible for nature to digest the waste. I believe that if we want to be fully circular, we need to create products that can be absorbed by the earth at the end of its lifecycle. Therefore, we need to change the very composition of our products. An example is the composition of plastic. It is already possible to create plastic where it can consist of plant-based cellulose fibers, which is more environmentally friendly. I suggest the industries at the ZKD in Den Haag to change their current plastic use into a biodegradable form of plastic, to make the circular economy fully circular.

Secondly, the circular economy suggests that we limit our resource extraction by using waste as a resource. However, the population is growing, which means we would still need to keep extracting new resources to comply with the growing demand. This does not even include yet the globally growing wealth and the increased demand for products in the world.

All in all switching to a circular economy is by far not enough to meet the current demands. We need to produce products that can easily absorbed by the earth itself and drastically decrease our current consumption.


Small (and fun!) steps to a waste-free world

A big challenge the world is facing today is the problem of too much waste. Waste is very harmful for the environment if left there, but also creates a lot of CO2 emissions when burned. Apart from that, materials are also getting scarce, especially some types of metals. To handle both problems at once, we need to move towards a circular economy.

The concept of circularity means to make no more waste: reuse every material which is used in old products. This can be done in different ways. For example, you can reuse the product in a different way, or recycle the materials the product contains to turn it into something new. Although a big part of waste is not made by consumers but by companies and governments, every little step helps. If consumers only buy more sustainable and circular products, this will eventually also make a change in the way how products are produces. I will just give you some examples which I think are great. There are many more, so next time you buy something, have a look if there is a circular alternative as well!

There are thousands of different initiatives for reusing or recycling materials into new things. I really like this NGO that makes bracelets out of plastic waste collected from the oceans. ( It was founded by two surfing teachers and by purchasing one, you help to make it possible to collect more plastics out of the ocean. Another very way to reuse materials is done by several companies who make bags out of plastic waste, old airplane chairs or even rubber boats! ( And besides that your bag has a great story to it, agree with me that you will look very fashionable as well!


A different approach to work towards a circulai, waste-free world is to only use biodegradable materials, which won’t harm the environment as waste. Peeze is a company that makes coffee cups out only bio-based materials instead of plastics and aluminium, which means the cups are totally biodegradable. (

Another thing which I recently found is Knot-wrap by Lush. ( This is a very nice alternative for wrapping paper around presents. It looks and feels like a small scarf and is available in a lot of different colours and patterns. An example:


They are and not only useful for wrapping other gifts up, but also usable as scarf, head band or tea towel. It is easily washable and reusable many times. If used for gifts over and over, this will save of paper! On top of that, it is also completely made out of recycled materials. It takes two small plastic bottles to make a knot-wrap.


As you can see, there are a already made lots of product in a circular way, and this is a good step towards the future. Although all these changes only are small steps, they can help to start bigger changes on a way to a waste-free world!



A recipe for the transition to renewable energy

Students of the sustainable development minor in Leiden are diligently posting blogs at the moment. This is in line with our current research projects. The goal of the research of my group is to advise the municipality of Leiden on how to motivate their public institutions to change to a more green energy provider.

In this blog I also intend to advise the municipality of Leiden on how to the municipality and its citizens can be motivated to implement a renewable energy initiative. To do this, I will discuss succes factors of renewable energy initiatives and how they can be used to implement other renewable energy initiatives in Leiden. Since I am the student psychology of the group, I will use a psychological theory to explain this. But first we might need a clear understanding of what the theme is.

1. Start by learning what renewable energy and the energy transition is

For heating, electricity and gas we now mostly use fossil fuels such as oil and coal. These are non-renewable, finite resources and therefore becoming more and more difficult to extract. The results in fossil fuels, becoming too expensive for you, or too damaging for your environment. We need to transit from fossil fuels to renewable energy sources. You might want to check out a detailed explanation of the renewable energy concept in the short and easy to understand video below.

        Video by Dane Bliss Design

2. Add the psychological theory of planned behaviour

Now the theme of this recipe is clear, we have to know how the end product (implementing a renewable energy initiative) can be achieved. To motivate or make somebody behave in the desired way, the theory of planned behaviour can be used. An illustration of this is given below this paragraph. The way to behaviour starts with the determinants attitude, subjective norm and perceived behavioural control:

  • Attitude is the degree to which an individual evaluates the behaviour as favourable or unfavourable
  • Subjective norm is the degree to which an individual feels social pressure to perform or not to perform
  • Perceived behavioural control is the ease or difficulty of performing behaviour. This can be past or anticipated obstacles

These three can influence each other (arrows going back and forth between them) and influence the intention to perform a behaviour. The three arrows to intention are the estimation of succeeding. Intention is how hard an individual is willing to try or the degree of effort planned by an individual. Intention directly influences behaviour (the arrow in between the two) The arrow from perceived behaviour control to behaviour stands for the actual measure of succeeding. The rule is: the more favourable the subjective norm and attitude, and greater the perceived control, the stronger the intention to behave is. So to motivate or change behaviour, the determinants should be the target.

The theory of planned behavior by Icek Ajzen

3. Shower with 7 succes factors

Succes factors are needed to know what to aspects to focus on when it comes to renewable energy. There are a number of succes factors that have proven to be helpful in municipalities to produce a significant amount of renewable energy or start a successful renewable energy initiative or project. The succes factors are:

  • Climate change
  • Economic advantages
  • Enthusiasm for technology
  • Local image
  • Political resolutions
  • Social Capital
  • Regional power suppliers

These succes factors influenced the determinants of the theory of planned behaviour positively, which made the intention to implement a renewable energy initiative stronger and consequently changed the behaviour into implementing a successful renewable energy initiative.

4. Mix the psychological theorie and the succes factors

The succes factors can influence determinants of the theory of planned behaviour and consequently end in the desired behaviour and end product. (implementing a initiative of renewable energy) The succesfactors are categorized according to their influence on the relevant determinant. It is also explained how the succesfactors can influence the determinants.


  • Climate change. By supporting renewable energy climate can be mitigated and therefore seen as a favourable evaluation on implementing a renewable energy initiative.
  • Economic advantages. By switching to renewable energy, money can be saved on the long term because extracting resources are mostly free (e.g. extracting sunlight). this way implementing a renewable initiative can be evaluated as favourable.
  • Enthusiasm for technology. This can have a positive influence on introducing renewable energy to other people and therefore make a renewable energy initiative favourable for other people.

Subjective norm:

  • Local image. The municipality can be seen as working on the Paris Agreement and in that way positively evaluated. The municipality can be pressured to perform the initiative to get that positive evaluation.
  • Political resolutions. If a strategy for renewable energy initiatives embedded in law then the municipality feels pressured to make perform this strategy and implement renewable initiatives.

Perceived behavioural control:

  • Political resolutions. Sharing the same strategie makes it easier to implement a renewable energy initiative.
  • Social capital. This is the investment in a relationship or social structure that helps to achieve an individual or collective goal. If you communicate with other parties, it becomes easier to reach the goal of implementing a renewable energy initiative.
  • Regional power suppliers. By effectively using available potentials for example (e.g. producing biogas with geothermal power), it is easier to change to renewable energy.

5. Finish off with integrating the mix in your municipality and bake until an implementation of a renewable energy initiative is made

I hope following this recipe will help the municipality of Leiden to implement a successful renewable energy initiative.

Scanning for Potential

Many cities want to implement a circular economy. But identifying opportunities for this can be quite hard, because the resulting systems are almost by definition complex and highly interconnected. Thankfully a new tool was recently introduced by Circle Cities Programme, the City Circle Scan. After an initial small pilot scan done on the city of Glasgow, it has now for the first time been successfully used on a large city. With help of TNO and Fabric, Circle Cities Programme has applied their scan to the city of Amsterdam.

The City Circle Scan has four phases. It all starts by mapping of material flows and added value, followed by the evaluation and selection of chains. The next step is visioning, in this phase the current system is re imagined in a circular way, with multiple visions developed for each chain. The final phase is project selection and formulation of action points, which results in detailed strategies to re shape the current chains into circular ones.

The scan of Amsterdam revealed two promising chains, the first of which is called The Construction Chain. The report predicts implementation of this chain will lower both annual material import and GHG emissions by half a million tonnes. This is respectively 33% and 2.5%. Quite size able savings. This is achieved by first of all simply using less materials through smarter design. The next important step is better recycling, the plan proposes better separation of the waste streams related to construction, further resulting in high value recycling. Now none of this is revolutionary stuff, which is why the last step is important. Through the creation of an online marketplace for these recycled materials, the hope is to breach the gap between demolition and construction so that the old recycled materials will actually end up in the new smartly designed buildings.

Construction chain
The Construction Chain

The second chain is called The Organic Residual Streams Chain. This chain is predicted to achieve a 600 thousand tonnes reduction in GHG emissions and nearly a million tonnes worth of material savings. The basic outline of the chain has a lot in common with the Construction Chain as it also aims to improve the separation of waste streams and to then utilize these streams in the smartest way possible. Again, this is mostly common sense, the real power behind the chain is the proposed central hub for bio-refinery. This facility is meant to refine all sorts of household and commercial organic waste into new high value materials.

A project is already in place to transform organic waste into useful resources.

Organic Residual chain
The Organic Residual Streams Chain

If both these Chains are put into action the total savings will be 1.4 million tonnes of material savings and 1.1 million tonnes of GHG emission reductions. On top of this, predictions are the chains will create €235 million in extra value and up to 1900 new jobs in the construction and agricultural sectors. Now, unfortunately these chains are tailor made for Amsterdam so a revision will be necessary to make them applicable to Leiden. To do this, Leiden could also apply the scan and reveal how they could make their construction and organic waste management circular. And who knows what other opportunities the scan might turn up?


Circular Amsterdam: A vision and action agenda for the city and metropolitan area

Wanted: Change

Globalization has caused us to obtain our daily products from all over the world. When we take a look in an average store all the products come from all over the world. In our current world this is a major problem since transportation is not done in a sustainable way, and even in the most optimistic scenarios it will not be for a significant amount of time. Therefore not only making transportation systems more sustainable but also creating a more locally based economy will contribute to a circular and sustainable society. One of the crucial things that a government has to do is to care for its citizens, since environmental problems already are a major threat and it will be a huge problem if we do not attack this problem, it is the task of the government to protect us and lead the way towards a sustainable society.

It is unacceptable that plastic products made from crude oil are for sale for only a few cents while they are shipped from the other side of the world. The real cost for society when climate change and resources are accounted for is much higher. Therefore if it is the task of the government to attack climate change and protect us they should tax these products according to their real costs and invest that money into a sustainable future. This is for example already done for other unwanted products such as alcohol and tobacco. Besides this unfair pricing, our personal lifestyles are a major influence on the environment. If nobody would buy these products there wouldn’t be a problem in the first place. However we wouldn’t want the government to prohibit us from buying whatever we want since we all agree on the importance of living in a free society. On the other hand we are all greatly influenced by media en advertisements so the question is, are we deciding for ourselves anyway?

In the Netherlands we all live in cities and our lifestyles quite resemble each other, so when the general opinion of these products changes the consequences will be enormous. In the end even the biggest of companies are all dependent on their customers. That is why the government should do advertising on environmental problems. When the government makes a statement on an educational level this might push citizens towards acting on their values. For example make a postbus 51 clip on climate change. Also an obligatory program on sustainability in high school, and affection with nature programs on primary schools could be very helpful. This will cause major leverage in society for changing towards a sustainable society, which will cause all political parties to choose for a more environmental friendly approach, not matter if they are right or left sided.

Now that elections are coming up it is important to make voters aware of the importance and to force all parties to choose for a more sustainable approach. When people are influenced by advertisement to choose for a more sustainable future in the form of new tax regulations charging unwanted products this will cause the biggest changes. In the end the only way we will be able to create more sustainable cities is if we want it ourselves.

Your final good deed

A wooden casket with on top gorgeous floral arrangements is being carried across the cemetery. Followed by a procession of mourning silent people the casket arrives at the grave where tombstone marks the final resting place of the deceased. We want to give our loved ones a funeral they deserve. However, such “traditional” Western burial is the worst ways to dispose of a body.

The impact of a funeral

Reports of Netherlands Organisation for Applied Scientific Research (TNO) show that burial is the most stressful for the environment, followed by cremation. The least stressful is a technique called alkaline hydrolysis. With this technique the body is being dissolved under pressure in hot water with potassium oxide.

Watch this video on how alkaline hydrolysis works

In the reports the impact on the environment is indicated among other things in shadow prices. These prices are the costs that have to be made to compensate the effects of the funeral techniques on the environment in euros.

The total environmental impact of the funeral techniques is between €2.59 for alkaline hydrolysis and €50.83 for a burial for an average deceased person. Cremation lies between those two, €48.47.

With burials, the biggest factor of impact is the space it takes to bury someone, costing 19.26 euros to compensate. The second biggest factor is particulate formation, 13.44 euros, followed by water supply depletion, 10.58 euros.

The biggest factor with cremation is particulate formation, costing 18.37 euros. Also cremation has a big effect on the water supply, its shadow price is 10.35 euros. Eutrophication, the enrichment of a water body with nutrients causing loss of biodiversity and depletion of oxygen, comes third with a shadow price of almost 7 euros.

The shadow price of just 2.59 euros for alkaline hydrolysis doesn’t mean the process isn’t stressful for the environment. It means that costs are compensated. Some of the effects categories have negative values. The water supply depletion costs for alkaline hydrolysis are 4.53 euros, but the costs for human toxicity are -2.15 euros. Together with the negative value for particulate formation, -2.07 euros, and the values of other effects categories, makes that alkaline hydrolysis has a net shadow price of 2.59 euros.

Screen Shot 2018-01-14 at 20.37.20
The environmental impact in shadow prices of burial (left), cremation (middle) and alkaline hydrolysis (right) (TNO 2014 R11303)

So what to do?

Keeping in mind that an average burial costs between €8,500 and €11,000, why don’t we all choose for the greenest and much cheaper version? The main reason could be the fact it is not legal in the Netherlands. The research done by TNO has been conducted on behalf of Yarden, a Dutch funeral organisation and insurer. The aim of the research is to provide information needed to change the law regarding funeral techniques in the Netherlands. This law states that one’s body may be buried, cremated or donated to science.

The two funeral techniques apart from burial, provide the great advantage of being able to recycle metals which otherwise would be lost in the ground. With alkaline hydrolysis this advantage is extended to the capability of recycling noble metals. This recycling results in a compensation of environmental effects.

For now, we can only hope that when our time has come the law permits us to do our final good deed for this world.