Cape Town to Joburg - what it costs the environment

I’m not a big fan of carbon offsets. I think it’s far more important to change lifestyles than to think we can go on generating emissions with impunity. So when I travelled recently to a conference in Johannesburg, I decided to see if I could balance my carbon budget with other lifestyle choices related to travel.

The house I am living in now in Cape Town was chosen specifically to allow me to commute to work by train, allowing us to survive with only one family car. In the past six years, I have driven to work no more than six times. Is that enough to compensate for my flights to Joburg?

Many cars emit 150g of CO₂ per km. I travel 25km a day to and from work by train, so I am saving 75kg of emissions each month. A round trip from CT to Joburg generates 300kg of CO₂ per passenger, so by commuting by train, every year I am saving the emissions I would generate from 3 return flights.

You will realise that my train travel does produce emissions, since the electricity used by Metrorail is generated using coal. But then I could also argue that by not owning a second car for my family, I am saving more emissions, since making a car can produce as much carbon emissions as driving it – 17 tonnes for the average car.

So yes, it’s complicated, and I fly to Joburg more than three times a year, but it’s useful to think about the implications of the various travel choices we make. And living in South Africa, which is ranked number 12 in the world for worst carbon emissions per capita, this is a big issue.

In 2008, SA generated 8.93 metric tonnes of CO₂ per capita – nearly double the world average of 4.76.  This is far better than the US (18.0) but slightly worse than the UK (8.5).

There are many carbon footprint calculators on the internet. I used these sources for the statistics in this post:

Flight emissions from the International Civil Aviation Organisation: http://www2.icao.int/en/carbonoffset.Pages/default.aspx

Car emissions in general: http://www.carpages.co.uk/co2/

Car emissions by model: http://calculator.carbonfootprint.com/calculator.aspx?tab=4

Carbon footprint of car manufacture: http://www.guardian.co.uk/environment/green-living-blog/2010/sep/23/carbon-footprint-new-car

World Bank CO₂ emissions by country: http://data.worldbank.org/indicator/EN.ATM.CO2E.PC?cid=GPD_27

sink or swim - professional ethics under climate change

A key challenge for planning and design professionals is figuring out how to incorporate the uncertain impacts of climate change in their plans.

We try to avoid building in flood-prone areas, but we haven’t forecast how climate change will alter flood zones. And what about sea level rise? If you buy a property that's less than 2m above sea level, it could be like a 99-year lease: at the end of it, you walk away with nothing.

There are lots of other areas where change matters. Hotter weather means we need to work harder to keep buildings cool without using more energy for air conditioning. Heavier rainfalls mean we need to design stormwater systems to carry the load (or hold back the peak flow longer). Less rain in growing seasons means we need more efficient irrigation systems, or different crops. Stronger winds mean buildings and other structures need to withstand the extra pressure.

But we don’t know how severe these changes will be, so it’s hard to set standards to guide engineers, architects and other designers. And we depend on these standards for responsible management of design risks.

And that’s just for adapting to change.

We also need to understand how to mitigate climate change through reduced carbon emissions. If a country like South Africa is going to achieve targets, we’ll need to change the way we plan projects and evaluate designs.

It’s all very well saying more people need to use public transport, for example, but how should transport planners look at the way they identify infrastructure needs? We routinely perform analyses that see how congested the roads are, and recommend improvements to reduce traffic delays during the peak periods. If we keep doing that, we’ll encourage more and more car travel, until eventually we run out of space to widen roads, and we’ll have a system that doesn’t work for cars or buses or even the pedestrians and cyclists who might dare to navigate this heavy traffic.

We should see it as unethical for professionals in the built environment to continue with business as usual. Some change is inevitable, and we need to do what we can to allow cities to adapt, and prevent avoidable change. If we don’t, it won’t just be the next generation asking, “what were you thinking?” but also the litigation lawyers rubbing their hands in glee at the tsunami of cases brought for design failures.

Engineering standards change as new materials are used in construction, and new building methods are adopted. These things change the science on which design is based. If they were not updated, we would be negligent. Climate change presents us with the same need to update our methods of analysis. The best science available says that change is coming, and it’s time to do something about it.

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If you are interested in the debate about sea level rise, have a look at Skeptical Science, where you'll find some healthy discussion between people who believe it's happening, and those who don't. The discussion covers topics like expansion of water as it heats up, how silt does (or doesn't) raise sea levels, the influence of building dams on sea level, the absorption of carbon dioxide by the seas, the role of melting glaciers, and so on. You could view original article in the link as just an intro - there are pages and pages of comments that are very informative.

Cape of Storms getting stormier

The City of Cape Town has issued the December 2011 issue of its bi-annual Enviroworks newsletter, appropriately themed around climate change. It covers the major socio-economic challenge of climate change, with contributions by leading experts. There are articles on how the Western Cape’s climate can be expected to change, the energy picture and the Climate Smart Cape Town campaign. There’s also a piece on the African Mayors Climate Change Declaration.

Bruce Hewitson, South African Research Chair in Climate Change and Director: Climate Systems Analysis Group (CSAG), and an IPCC Lead Author, summarizes our challenge:

We have a good understanding that the region will continue to warm, and that the warming will be greater further inland away from the coast. Likewise, we are confident that, on average, the rainfall intensity will increase. We are reasonably confident that the large high-pressure systems that cause the south-easter in Cape Town will strengthen. We have an emerging understanding of the pattern of rainfall changes and the impacts on seasonality. We can develop messages that, in a risk management context, are useful information to inform our decision making.

I mentioned Hewitson’s regional climate modeling work when I wrote about COP15 in Copenhagen.

mix your own cement

Cement is massively energy-hungry in its manufacture. And it also uses a lot of energy in transporting it from the factory to your building site. So here's a business, called Origami 4, that lets you order just the essential chemicals online, while you supply the bulky sand and materials that are costly to transport.

This is not just a case of buying a bag of cement and mixing with sand and stone as you might do normally to make concrete. You are actually mixing the cement itself in a special machine, BEFORE even making the concrete, and packing it in bags like the ones you would buy at the hardware store. So the transport saving is significant if you make a lot, and have sand available nearby. And if you use this method, you're going to want to make a lot, because the cement manufacture plant you'll need to buy won't be cheap, I'm guessing. But it doesn't take up much space.

Sounds great for community-based building projects.

it might be winter, but the water's hot

Well, our old water heater decided to pack up, so that was a sign to go ahead with a solar water heater, which was installed a couple of weeks ago. Had a choice of evacuated tubes or a flat panel, and it wasn't that clear-cut. Apparently the evacuated tubes are more efficient than we need in the South African summer, and they can over-heat the water to the extent that water is wasted as the pressure valve releases water. In winter the tubes make sense, but the consensus seemed to be that overall, over the course of the year, flat panels are best for this climate.

Eskom seems to agree with that assessment, as the rebate is higher for the flat panel system. But they are gradually reducing the rebate, apparently with the intention of phasing it out. No idea why.

Next thing will be to find a use for the old water tank, which we left in the attic so it could be used for a gravity-fed recycled water system.

going solar at home

OK, it's been how many years? I bought a cordless electric lawn mower back in 2004 with the idea of gradually replacing most of my electrical tools with cordless ones so that they could be charged from solar panels.

I have now finally splashed out and bought my first solar pv panel, battery, regulator and inverter. The lawnmower is no longer running - just needs a new battery, I think - but now I can start weaning myself off the grid.

The catalyst for getting the panel was a trip to the AfrikaBurn festival in the Karoo, where there is no power, no water and no cellular phone reception. In fact nothing at all. Thousands of people descend on the temporary Tankwa Town in the desert, and a week later they pack up and leave nothing behind. It's the little brother of Burning Man in Nevada, USA.

As it turns out, I am getting a ride to AfrikaBurn with a colleague, as my car has needed emergency repairs, so I can no longer bring the solar equipment. But at least I've made the initial leap. Here's what I bought (and if you're in Cape Town, I recommend SetSolar as a supplier):

90W panel manufactured right here in Cape Town by SetSolar (model M750P)

• Steca 6.6F - 6A charge controller 12/24V
• One 100Ah deep cycle battery 12V
• Cotek 350W pure sine wave inverter 12V

Total bill: R5,700 (about USD 850)

That's not big enough to run more than a typical desktop computer for more than three hours when the sun's not shining, but it's easy enough to add batteries and panels as the cash becomes available. But my initial purpose is to run a small water pump for a grey water system I hope to build. I will keep you posted on that too.

even insects have to live somewhere

Arup Associates has won the ‘Beyond the Hive’ competition to design a hotel for insects. The competition was sponsored by British Land and the City of London to celebrate 2010 as the ‘International Year of Biodiversity’. Selected from five shortlisted hotels, built and placed in parks around London, the jury included Paul Finch (Chairman of CABE and Editorial Director, Architectural Review and Architects’ Journal); Sarah Henshall (BugLife The Invertebrate Conservation Trust); Adrian Penfold (Head of Planning and Environment, British Land); Peter Wynne Rees (the City Planning Officer); and architect Graham Stirk, (Rogers Stirk Harbour+ Partners).

The façade of the hotel consists of a series of compartments based on a Voronoi pattern – the rib structure of a dragonfly’s wing, generating a series of voids. The compartments provide the supporting armature and an ordering structure for a variety of recycled waste materials and deadfall that are loosely inserted into the voids. The sides of the hotel are accessible for butterflies and moths and the top is suitable for absorbing rain water through planting.

building with rice

A green building material that's actually... white.

Sticky rice, a staple in many modern Asian dishes, was also the secret ingredient in super-strong mortar used in China some 1,500 years ago, a new study suggests.

Much less carbon emissions than cement, by a long shot. But everything has some impact - in this case, agricultural land and water, at the very least. Growing rice as a construction material would be a bit like using farms for producing corn-based ethanol, but I just love the low-tech aspect of it. [via kottke.org]

bamboo magic

Bamboo laptop case.

How many things can you make with bamboo? Lots, according to AfriGadget.

Lekuama Ketuafor is the proprietor of Bamboo Magic, a one-man cottage industry he’s started to supplement his work as a teacher.Using a set of simple hand tools, glue, varnish, skill and loads of patience, Lekuama finds ways of using bamboo—a ubiquitous, low-cost, renewable material—in ways many people have never imagined.

off the rails

While I think futuristic visions of transport systems are unlikely to solve our current challenges, it's always good to dream. Here's a concept I haven't seen before, courtesy of Dimitar Kyosev:

In this innovation the track is actually carried by the train. The Tubular Rail concept developed from the observation of the relationship between the balance point of a beam at rest on two points. The inventor noted when sliding a pencil off the edge of a desk, given a uniform weight distribution, the pencil - or any beam - could be pushed to almost 50% of its length before tilting would occur. Reversing the orientation of the wheel and the rail is truly unique. By placing the wheel (or roller) permanently on a fixed structure and the rail on the now strengthened car, the car itself bridges the space between the rollers. Tubular Rail Technology uses the principle of the cantilever beam - a projection anchored at one end. Since the car is moving within- and is held by - the support rings (stanchions), the effect is to create a cantilever beam. The beam is fixed in its vertical orientation but mobile in its horizontal orientation. Therefore this rolling cylinder is constantly shifting from a cantilever beam on the ends to a post and beam (in its middle) and then back again. That allows drastic reduction of construction costs.