This paper presents an analytical review of the interaction between urban density, climate
change, and sea-level rise. The paper has a focus on two main themes: the interaction between
urban density and the generation of greenhouse gases and how this affects mitigation strategies;
and the consequences of climate change on urban settlements of varying population densities
and how this affects adaptation strategies. Throughout, there is a recognition that changing
population densities in urban centres can both affect, and be affected by, global environmental
change.
Firstly, and as is already well known, climate change is caused by the emission of greenhouse
gases, primarily from the combustion of fossil fuels. Greenhouse-gas emitting activities are
distributed in a spatially uneven manner. At a global scale, the 20 percent of the world’s
population living in developed countries account for 46.4 percent of global greenhouse gas
emissions, while the 80 percent of the world’s population living in developing countries account
for the remaining 53.6 percent. The United States and Canada alone account for 19.4 percent of
global greenhouse gas emissions, while all of South Asia accounts for 13.1 percent, and all of
Africa just 7.8 percent (Rogner et al 2007). Even greater differences can be seen if individual
countries are compared: per capita carbon dioxide equivalent emissions vary from less than one
tonne (e.g. Bangladesh 0.38; Burkina Faso 0.60) to more than twenty tonnes per year (e.g.
Canada 23.72; the USA 23.92; Australia 26.54) (United Nations Statistics Division, n.d.). Even
within countries there are spatial disparities in the production of greenhouse gases: per capita
emissions in New York City are only 29.7% of those in the United States as a whole (PlaNYC
2007); those in Rio de Janeiro are only 28.0% of those of Brazil as a whole (Dubeux and La
Rovere 2007), and those in Barcelona are only 33.9% of those of Spain as a whole (Baldasano et
al 1999) (for a more detailed discussion of this topic, see Dodman 2009).
The paper, therefore, examines the implications of different urban densities for the emission of
greenhouse gases (particularly, although not exclusively, in high-income countries), and the
implications of this for global climate change. The paper explores the relationship between form,
density, economy, and society within cities to assess whether particular spatial patterns can have
a positive or negative effect on the emission of greenhouse gases and consequently climate change