Interdependence is Sustainability

The Mesh by Lisa Gansky is a recent book on the business of sharing. The consumption economics is being rewritten in the current global scenario where everyone is looking for an answer that could sustain the future of mankind. This book gives numerous practical examples where new business models are reducing human consumption, increasing community usage and improving quality of the products. The planet should move away from use and throw tendencies which are a drain on our resources and reuse/ recycle is making sense more and more sense. In poorer countries it happens naturally as the very poor of society can make a living out of trash collection and recycling (though the methods adopted may not be very sustainable). While in the rich world, it is hard to make recycling feasible with higher costs and lack of will associated with it. The Mesh talks about products that are essential but seldom use and can therefore be brought into the public domain for sharing from the private domain of individual use. The book gives examples of old product types from cars to clothes to tools to real estate being available for shared usage. 


A recommended read to keep oneself updated with business strategies in the new cyber-age.

Green Roofs as strategy to mitigate city problems (Part 2)

Following to what we said last week, about how good green roofs worked to mitigate Heat Island Effect, one of the biggest challenges of cities nowadays, we want to continue explaining how good they perform as well, when we talk about another huge city problem:
Water Storm Management.

Climate change is altering the natural water cycles and the rain patterns in mostly every part of the planet. It is increasing the seasonality of rainfall and risk of flooding. When this happens in a natural environment, the native soil by absorbs and filters the water thru its permeable condition, but in urban areas the impervious flooring materials and buildings structures send all the water directly to the underground drainage causing peak flows that damage dramatically the infrastructure. The risk of localised flooding effects is bigger therefore in the cities. Images of flooding all around the world are common now in our daily newspaper cause climate change, and the amount of them will just increase.

Green roofs reduce the amount of storm water run-off and mitigate the peak flow rates. In summer a green roof can typically retain between 70-80 % of the rainfall run off. (Living Roofs and Walls Technical Report. London 2008)

In cities, "green roofs" are a great method to help out reduce the Heat Island Effects and the Water Storm Effects, but beyond that, green roofs are excellent for other reasons. They increase the biodiversity of a place and they enhance the quality of the space. If combined with Solar Panels, they increase the efficiency of the photocells as they help keep them cooler thru the evapotranspiration. 

The fact that there are being installed mostly in temperate climate places such as Germany, doesn’t mean though that they perform worst in desserts or in other climates. In fact, as insulators, green roofs have a very high efficiency in hot climates, reducing the cooling loads of a building that would save energy demand.
The cost of the green roof in this case with the irrigation system that needs should be measured against those potential annual energy savings and the reduction of the cooling system. Intensive roofs perform as good as extensive roofs, but the cost, the irrigation demand and the maintenance is so high that is not recommended on dry climates.
In tropical climates, in places such as Singapore, green roofs will be great efficient since there will be no need for irrigation system and very little maintenance. Intensive roofs are more cost efficient here and they will provide their own benefits as enhance biodiversity and amenity space to increase the value of the property.
In cold climates such as Germany, green roofs are not so efficient as insulators but in a city context and done extensively they do contribute to mitigate heat island effects, water storm discharge and in the summer time help to reduce the cooling loads of the building. They don’t need irrigation system but they need insulation panels. Extensive roofs can be used as much as intensive roofs as they are both liable.

In Mediterranean climates, if done in a large scale, green roofs can help thru evapotranspiration to increase the amount of precipitation inland, as they raise the amount of humidity in the air, which is another big consequence of the dense urbanization in the coast areas. (Estudios Ambientales del Mediterraneo studies done by Millan Muñoz)

In general terms, we can say that Green Roofs are good for many reasons and they should be considered to be used almost in every situation. 

Go to www.livingroofs.org for further information. 

Image from ACROS Fukuoka Project in Japan.
Source: http://www.metaefficient.com/architecture-and-building/amazing-green-building-the-acros-fukuoka.html#more