Geography Reference
In-Depth Information
source of greenhouse gas emissions from human activity comes from electricity
generation and heating (43 %), with the next two largest proportions generated by
manufacturing and construction (18.2 %) and road transport (15.9 %). Hence it is
necessary to understand the growth of these fossil fuel sources and the prospects
for replacing them with renewable sources if the current build-up of greenhouse
gases is halted in order to reduce the current unsustainable levels of the use of these
resources.
Most issues involved in reducing the negative effects of the use of fossil fuels
go beyond the ability of urban areas alone to influence the situation. The crucial
regulatory or incentive decisions to reduce dependence on fossil fuels are usually
taken at a state or corporate level, rather than in urban municipalities, although in
democracies the large number of urban voters can influence the political decisions
to alter policy. Although it is popular environmental opinion to deplore the use of
these fossil-fuel sources, it is salutary to remember that our industrial progress,
and especially the growth of cities, has been based on the ability to exploit these
sources, principally coal, oil and gas, in which subsequent technological advances
have aided the extraction, transport and burning of these sources, and in doing so
have created huge infra-structures and employment levels to support the generation
and transmission of power. Hence the functioning of our cities is highly dependent
upon the energy obtained from these fossil fuels, not simply for electricity, heating,
and powering machinery, even though the generating plants may be distant from the
cities, but also for transport.
This dependence stems from the fossil fuel advantages over other energy sourc-
es, namely: having very high calorific output per unit; portability, given the techno-
logical improvements in transport in the last century, though some fuels are expen-
sive and bulky; most are easily storable; their use in the energy-producing systems
developed from the late nineteenth century onwards have made it relatively easy
to switch production on and off; and most have lower costs per output of energy
than renewable sources at this time. Certainly the various fuels vary in their utility
within these categories; for instance, oil is more portable than coal, although it takes
more processing to produce the product. But overall, the advantages of fossil fuels
remain, even though increasing environmental concerns about their negative effects
have altered attitudes about their continued use and the amount of their reserves.
The result has been a search for alternatives, leading to interest in the use of alterna-
tive renewable energy sources.
Despite the remarkable increase in the proportional growth of renewable en-
ergy sources in the last decade, all the evidence points to the continued dominance
of fossil fuels for the next 20 years and the foreseeable future. This is illustrated
in Table
5.1
, which shows the estimates of energy sources published in the most
respected and comprehensive international source of data on the topic, the annual
World Energy Outlook published by the authoritative International Energy Agency
based in Paris which shows figures for 2011 (IEA
2013
). The second and third rows
of the table show that energy production increased by 81.1 % in the 30 years since
1980 and are likely to show another increase of 42.6 % by 2035 if current energy
policies and trends in growth continue. However it is expected that in the light of
