Geography Reference
In-Depth Information
52
Problems of Unsustainable Practices
Urban places are the sites of many of the most significant unstainable practices.
One of the most important contributors to this characteristic is the burning of fossil
fuels, which has been the energy source for our industrialization and urban func-
tioning. In the past the negative externalities of fossil fuel use were usually ignored,
they were part of the price of progress. Even when a problem was obvious, such as
the infamous London smogs from the nineteenth century, it was considered to be
city-specific and it took over a century before serious action was taken to mitigate
the problem. This intermittent type of pollution reached a new peak in four days in
December 1953 (MO). A fog over the city became toxic when the emissions from
the coal-burning fires and furnaces in the city became trapped because of a tempera-
ture inversion with warmer area above. The fog not only meant that visibility was
less than a few yards, but created respiratory problems in large numbers of people
that contributed to thousands of deaths. This crisis did lead to a clean air act which
involved the banning of the use of coal in household fires in London.
Although many other cities have also suffered from similar pollution caused by
fossil fuels in the last two decades, it has finally been realized that the burning of
this resource is having more than urban effects. The addition of carbon dioxide to
the world's atmosphere, mainly from fossil fuel use, reached 393 ppm in 2013, a
major increase on the 280 ppm at the dawn of industrialization in the late eighteenth
century. Along with other gases it is creating what amounts to a blanket or green-
house effect by absorbing more of the sun's rays, thereby warming up the earth.
Of course carbon dioxide is not the only gas that increases climate warming, al-
though it accounts for over two-thirds of the total. Methane, which has even greater
heat absorbent ability, accounts for another fifth, while water vapour, nitrous ox-
ide, halocarbons and ozone also contribute to the greenhouse effect. Although these
gases only account for 1 % of the atmosphere, which is primarily nitrogen (78 %)
and oxygen (21 %), this change in the atmospheric balance increases warming and
hence the amount of water vapour that the air can hold.
Most climate scientists believe the current warming trend is different to the other
oscillations that have caused climate changes in the human past, as seen by the
reports of the Intergovernmental Panel on Climate Change (IPCC
2013
,
2014
) that
was established by the World Meteorological Organization and the United Nations
in 1988. Their regular reports and the research of the vast majority of climate sci-
entists has led to the conclusion that there will be many negative effects of climate
warming. This human-induced trend will increase the intensity of extreme weather
events, especially violent tropical storms, and perhaps increase their number. There
is likely to be more heat waves, whose effects in cities will be exacerbated by the
heat-island effect of all the buildings. In addition, droughts in many already margin-
al areas may reduce agricultural production. There has been a marked increase in the
number of droughts in Australia and California in recent years which is leading to
a greater incidence of forest fires than experienced over the past half century, while
forest fires in the Canada are also well above average trends. Drought will also
decrease the water supply of many cities throughout the world. Large numbers are
