Climate Action 2011-2012

special feature
autodesk
CA2011 Exxaro_2.pdf
The role of modelling for
sustainable cities
Cities, where the majority of people now choose to live,
have become antiquated structures bursting at the seams and
subject to some of the worst effects of climate change. Yet
advances in conceptual urban planning design and building
information modelling (BIM) now enable urban planners
to model multiple scenarios, so that they can assess the
resilience of various plans to the three-pronged challenge
of changes in resource availability and demand, a changing
climate, and demographic shifts.
Unprecedented Urbanisation
For the first time in human history, over 50 per cent of
people live in cities (UN Population Fund, 2007) and, by
all accounts, this percentage will only continue to grow.
From an urban population of one billion in 1960, it took
25 years to add the second billion and only 18 to add the
third. And if projections prove correct, the fourth billion
will take just 15 years. This trend is being driven primarily
by India and China. Never before in history have two of the
most populous countries urbanised at the same time, and at
such a pace. According to Dobbs and Sankhe in McKinsey
Quarterly (2011), between 2005 and 2025, India will need
to add roughly 800 million square metres of floor space and
400 km of metropolitan rail annually. In that same time
period, China will need to add 1,800 million square metres
of floor space and 1,000 km of urban rail.
climate change front line
According to World Bank research, cities account for up
to 80 per cent of the expected US$80–100 billion per
year in climate change adaptation costs. But the necessary
adaptive measures will not be straightforward, because the
combined impacts of urbanisation and climate change are
not straightforward. For example, one 2011 study by Felix
Eigenbrod and others, in Britain, estimates that denser
populations will reduce natural water drainage, swelling
rivers that are within flooding distance of millions of urban
dwellers. But from the other point of view, these denser
populations leave more space for agricultural production
and carbon storage, essential infrastructure for any hungry
and energy-intensive city.
antiqUated infrastrUctUre
The Organisation for Economic Co-operation and
Development (OECD) estimated in 2007 that about
US$71 trillion, or about 3.5 per cent of the global GDP,
will have to be invested by 2030 in order to improve the
basic infrastructure worldwide – including road, rail,
Near photo-realistic rendering of a city model with conceptual design for a bridge
and waterfront park. Designed and rendered in Autodesk ® 3ds Max design software.
152 climateactionprogramme.org