Environmental Engineering Reference
In-Depth Information
This final extended chapter elaborates on some of the means by which this ambitious and
radical agenda can be realised. It covers the broader issues of climate change, and the centrality
of the sustainability debate, not so much in its definitional sense, but in looking at the ways
to 'get things done', and it uses the material from the case studies to illustrate the scale of
change needed and the difficulties involved. There are three additional substantive contributions:
the first covers the adaptive backcasting approach that has been developed as a flexible means
to identify sustainable transport futures and to use the dynamics of change to enhance outcomes.
Second, the critical importance of urban form and the structure of cities is restated as one
means to reduce the need for car-based transport and through the potential for shorter journey
lengths. Third, there is a commentary on the implications of achieving different scenarios in
transport, and in making progress on a variety of related themes. These include more thoroughly
understanding the rationales for peoples' travel, the role of transport in society, the modelling
problems and the importance of different forms of governance (the means of implementing
scenarios). Finally we restate the criticality of imaginative thinking in futures analysis, both
in the immediate term and over the longer term. Returning to the inspiration of Herman Kahn:
we need to start thinking - and achieving - the (currently) unthinkable in our future travel
behaviours.
Climate change, in Goffman's (1959) phraseology, has become 'frontstaged'. Alongside oil
scarcity, wider energy depletion, traffic casualties and impacts on city design, climate change
has become a central concern for decision-makers in transport planning and city planning.
Still, too much time has been spent on forecasting against historic trends, 'improving' modelling
methodologies and assessing transport impacts at the local level, such as modelling how much
traffic can be fitted through a junction, or a particular network. These are important issues in
specific locations, but relative to the strategic policy concerns of climate change and oil
scarcity, support for the macro economy, and achievement of improved quality of life and
well-being, they seem much less important. Sustainable transport remains largely an unresolved
policy area. There is still debate over its definition, the direction of change, and the type of
investments and innovations required to significantly reduce CO2 emissions and to concurrently
achieve wider environmental, social and economic objectives in transport.
Cities in the industrialised West are often very CO2 intensive in their travel patterns; the
cities in Asia and elsewhere usually much less so. There are very different baselines between
cities and within cities (in terms of the inner areas, outer suburbs and hinterlands). This large
difference in CO2 emissions within cities and city regions is under-appreciated and largely
overlooked when international, national and city-based targets are set. It is at these different
levels, however, that the transport investment, the city structure, and any gains, can be made
in implementation terms. The different baselines and opportunities require very different
strategies. For example, the emerging cities face very different realities to those in the
industrialised West. They often have much lower per capita incomes (and tax receipts) at the
national and city levels. GDP growth rates would need to be maintained at high levels for
decades to make up the difference, hence transport investment is limited. The focus here,
therefore, has to be on the less expensive and more inclusive modes, which means walking,
cycling and bus rapid transit - akin to the Curitiba and Bogotá models. Metro systems are
potentially unaffordable in many cities. The exception here might be the major cities in China,
and perhaps also in a smaller number of cities in India, or major cities elsewhere. In addition,
many cities are limited in terms of the actions that they can take, as decisions on issues such
