After Paris, no one can go round anymore: every sector will have to contribute to CO2 reduction, even the building and construction sector with regard to its material choices. And why not start immediately with the easiest solutions, the low-hanging fruit so to say, mainly the shamelessly framing of some materials as sustainable and green . Especially aluminium is pushed in a very misleading way. Aluminium is the most heavy impacted material when it comes to energy and CO2, nevertheless I regularly come across industry driven websites which profile aluminium as the ‘green metal’. Now thats a travesty. I rather would call is the blackest material, compared to coal among fossil fuels. The most significant property is the energy input in for mining and processing, The embodied energy. For aluminium it is around 220 MJ/kg , much higher as for most other metals ( between 25-50) and certainly devastating compared to wooden parts (around 10 MJ/kg)
Even more harmful is the random application of aluminium. Most aluminium, certainly in the building sector, can be replaced with materials with the same functionality but much lower impact. Aluminium is used where its is not needed, like window frames and even facade cladding. This is really squandering embodied energy and CO2 emissions, for such simple things like facades. Many alternatives are available, that have much less environmental impact, and contribute much less to climate change . And it happens that climate change is more or less the most important issue on the agenda for the next decades: facing droughts, water deficiency, food shortages, flooding cities and countries, large scale migration to name few. Knowing this, we still would like to clad facades with aluminium? Last year the Dutch NGO Urgenda won a law suit against the state of The Netherlands: The country was convicted for doing too little to protect its citizens against climate change: In the same line of thinking , using aluminium where there is a much lower impact alternative available, can be seen as a crime against humanity, obstructing climate policies.
A direct consequence is that we will have increase construction of off shore windturbine parks, to produce all the extra renewable energy because we ‘ like the view’ of aluminium facades? Because thats what it is. And all the energy and materials, going into windfarms , causing CO2 themselves, can be avoided by not using aluminium where its not necessary . The building sector has a responsibility here, which is very easy to commit to.
The industry is aware of this, of course. Which is why they move heaven and earth to rotate the image. As I read at one of the many industry led websites: [1] : “Aluminium recycling benefits present and future generations by conserving energy and other natural resources”. This would imply that aluminium is the solution to all our problems, it suggests that the more aluminium is recycled, the more energy is conserved, in the end we don’t use any energy anymore... While aluminium is a major cause . Its absurd, the issue is shamelessly turned around 180 degrees.
And : “ Today, recycling of post-consumer aluminium products saves over 90 million tonnes of CO2 and over 100,000 GWh of electrical energy, equivalent to the annual power consumption of the Netherlands.” Here recycling is thrown into the debate, and again, all our problems solved. What in fact can be read: It has cost that amount of impact (100000 Gwh) to produce aluminium in the first place, and that impact still exists, its not gone suddenly. If there had been used a alternative for the original material application, it would never have been needed to invest such enormous amounts of energy at all, and even recycling of aluminium would not have been required at all. Again, the picture is turned around 180 degrees again, and we are brainwashed.
To use aluminium for façades, ( or window frames, or partition walls, even drinking cans) makes no sense, is wasting resources, and accelerates climate change, compared to alternative solutions.
As mentioned above, not only it has created a lot of impact to produce, the “ impact” has only been a calculation. The energy or CO2 emitted has never been compensated, just like many of the environmental assessments like LEED, Breeam, or even LCA are only paper, bookkeeping, but without any consequence. ( except providing some rating stars that help sell projects…)
For wood or other biobased projects at least responsibility is taken to restore or regrow stocks, like forest management or FSC approaches. But never for metals: they are just depleted free of any restriction. Which can be seen as inequality is the treatment of materials, especially between biobased and non biobased. (Its a from of resource racism, as I have called this before) . Discussion about this is avoided of course. And aluminium saves or conserves nothing.
Then what about recycling, the aluminium (and metal) industry likes to focus on? Claiming it costs little (impact) to recycle, and a “high” percentage is already recycled. I wrote about the wrong use of recycling claims before [2] . Most important is that never is mentioned what the loop time has been: Aluminium cans for example are recycled at a rate of 50% in England, however the looptime is 6 weeks, which implies that after 1 year over 95% of aluminium is lost in nature, and new aluminium has to be produced.
There is nothing wrong with recycling of course but in comparing materials its a non argument: anything can be recycled, its not a distinctive property. Besides, a wooden beam most likely is more often re-used in its original form, as times that aluminium is melted for recycling.
Interesting is that the CEN tc 350 committee has advised not to include recycling in the functional system borders. ( known as module D)[3] Which is of course highly contested by the metal sectors. As in the Dutch normalization committee for ‘Sustainability of construction works’ : The metal industry admits even that they are in this committee to secure inclusion of module D. By the way, in this committee all members are from industries, not a single researcher or scientist is present. This is probably because every member has to bare its own costs for the work by the committee. Which is what you get when having a policy that the market should organize things by themselves.
Anyway: I have nothing against aluminium. Its a beautiful material. You only should not apply it when not specifically needed. In other words, Building sector, take your responsibility, and avoid aluminium as much as possible.
( this article has originally been published as a column in a Dutch building magazine: http://www.cobouw.nl/artikel/1647611-stop-met-aluminium )
1 International aluminium Institute: http://recycling.world-aluminium.org/review/sustainability.html
2 http://www.ronaldrovers.com/?p=31
3 European standards briefing paper by BRE: http://www.bre.co.uk/filelibrary/Briefing%20papers/98661-European-Standards-Briefing-Paper.pdf
