dendrite studios

Tuesday night (2/01/2007) saw the kick-off of our ‘How do we build well in a fundamentally changing climate’ seminar series. The title of the first session was ‘An overview of climate change and its implications’. We were fortunate to have two speakers who are both experts on this issue in the persons of Peter Willis and Stef Raubenheimer

First up was Peter, the Southern African Director of Cambridge Programme for Industry (our co-hosts). He regularly presents to senior executives and government officials on climate change and sustainable development.
Peter started his presentation by describing climate change as our ‘first ever global emergency’. “The question facing governments is whether they can respond quickly enough to prevent threats from becoming catastrophes. The world has precious little experience in responding to aquifer depletion, rising temperatures, expanding deserts, melting polar ice caps, and a shrinking oil supply. These new trends will fully challenge the capacity of our political institutions and leadership.”

Science of climate change 

One of the main purposes of this session was to give some grounding in the science of climate change. Peter highlighted the following facts: Most discussions on climate change centres around greenhouse gasses. These gasses (including carbon dioxide [CO2], methane [CH4], nitrous oxide [N2O] and water vapour) are so called because they cause a greenhouse effect. As in a greenhouse where heat enters but is then trapped causing above normal temperature, greenhouse gasses traps heat, from visible sunlight that reflects from the earth’s surface, and prevents it from escaping our atmosphere. While the greenhouse effect is a natural process and essential for our existence on earth, humans adding more and more greenhouse gasses into the atmosphere cause an enhanced greenhouse effect, upsetting the fragile temperature balance on earth.

For the 400 000 years prior to the Industrial Revolution, CO2 levels in the atmosphere has varied between 200 and 300 parts per million (ppm). Over the last 175 years this level has increased by about 100 parts to the current levels of 383 ppm. What is extremely interesting is that the variances in global average air temperature near the Earth’s surface, almost exactly mirror the changes in atmospheric CO2 levels. Consequently in the last 100 years, the earth’s average temperature has risen by about 0,7° C. (For a very good introduction read the Pew Center report entitled ‘Climate Change 101’)

Many scientist and policy makers refer to a target of 450 ppm that we need to try and stay below. In one slide Peter quoted research by Dr. Simon Dietz of LSE that predicts an eventual temperature rise of 3° – 4° even if we were to stabilize CO2 concentrations at 450 ppm (these estimates are slightly higher than IPCC AR4 which estimates the increase at just over 2° C). Global warming of this magnitude will have a significant effect on sea levels due to a melting of ice over land and geothermal expansion. This could have far-reaching impacts for coastal settlements such as Cape Town.

The conclusion from Peter’s brief scientific background was that the sooner we start doing something to reduce CO2 emissions and atmospheric CO2 concentration the better our chance of avoiding calamitous climate change. In touching on how we could turn this crisis around Peter set forth the challenge of building a low carbon society, rather than just plugging holes through reductions and adaptation.

Moving beyond green building 

Stef Raubenheimer, the CEO of international NGO SouthSouthNorth, was the evening’s second speaker. With reference to the scientific data that Peter gave, he focussed his attention more on the built environment. In particular since buildings consume about a third of all energy globally and much of that energy is derived from fossil fuels. (According to RIBA, architecture is responsible for 45% of carbon dioxide emissions in the UK.)

Stef also referred to his current work on long-term greenhouse gas mitigation scenarios for South Africa where they consider least cost alternatives to provide for SA’s future energy demands. His conclusion: We will need to do a whole lot better in order to get close to a reasonable atmospheric CO2 stabilisation.

He further challenged the audience to think way beyond the current notions of ‘green buildings’. Leading examples of green buildings, such as the BP head office, typically reduce CO2 emissions by 20% or so compared to similar buildings and they go some way towards capturing and recycling water. Buildings of the future, he said will have to emit 60% - 70% less CO2, capture and recycle all water and have to be almost completely recyclable. How we are going to achieve that, is a challenge that the built environment professionals need to resolve. One of the big stumbling blocks in getting there is the lack of relevant local data on embodied energy, energy use, CO2 emissions etc relating to buildings in Cape Town. Much applied research work will still have to be done in measuring base-line cases and specific interventions in order to inform the building practices of the future.

Some of the questions and responses from the Q & A session:
Q: What about the role of nuclear power in the future?
SR: The long term mitigation scenarios for SA assume several PBMRs and cutting nuclear completely from the picture will be difficult given that renewable energy would require a doubling in transmission capacity.
ADMIN: A 2 October Fin24 article quotes public enterprises minister Alec Ervin that nuclear power is the “most commercially viable, carbon-emission-free base-load technology for the long term”.

Q: When will new policy and legislation come in place?
SR: The Department of Environmental Affairs and Tourism has called 2008 the year for policy drafting and implementation should happen in 2009. The policy creation process will be a very complicated one, and architects should contribute to the process.

Q: Given the huge impact of vehicles on urban design, how will the cities of the future deal with this?
PW: The New Mobility Initiative that is active in Cape Town looks at this very issue.
SR: Although carbon-emission free cars are a possibility there is still the issue of embodied energy in manufacturing vehicles. Greater public transport is definitely the way things are moving internationally.
ADMIN: At recent TED conference, World Changing CEO, Alex Steffen referred to Vancouver as a successful example of urban planning that got North Americans to drive less.

Q: How do we implement more sustainable design given the current trend of enclosed suburban development?
ADMIN: Hopefully by the end of the series, we will all have a better idea. In the mean time, have a look at Greenbridge, a mixed use residential development in Chapel Hill, North Carolina.

The following questions were not addressed at the session and we hope that someone will attempt to answer them in this forum:
Q: How far will we have to go ‘backwards’ in technology to achieve green building?

Q: Where can one obtain information on the amount of CO2 emitted to manufacture building materials?

The next session (4/10/2007) is entitled ‘Overview of the Implications of Urbanisation and other ecological system pressures’. We hope to continue the exploration into how we can build well and build better.