Resources - Environmental Transformations - page 20

nineteenth centuries in Europe and North
America. From about the 1950s onwards oil and
natural gas started to challenge coal's status as the
dominant source of human energy. Oil and natural
gas have the advantage of being much easier to
extract from the Earth than coal (which still
depends on labour intensive mining practices),
and much easier to transport . Figure 2.2 reveals
that oil has now replaced coal as the most-used
mineral fuel, and that taken together oil and
natural gas provide over half of all the fuel energy
that is now utilized by humans.
What each of these mineral fuels has in
common, however, is that they are non-renewable.
By non-renewable, we simply mean that they have
been formed over very long geological time
periods, and once exhausted will not be available
again for human use. In an influential book
entitled The Last Hours of Ancient Sunlight , Tom
Hartmann argued that our current use of energy-
rich mineral fuels is akin to exhausting, within a
couple of hundred years, energy resources that had
been formed over millions of years of the Earth's
history (Hartmann, 2001). As the energy that is
locked up in mineral fuels such as oil, gas and coal

ultimately derives from the sun, Hartmann claims
that our current fossil fuel economy is based upon
a unique endowment of ancient sunlight. This
means that with the exploitation of mineral energy,
which has become possible during the Anthropo-
cene, recent generations of humans have been
granted access to millions of years of the sun's
energy.
The fact that mineral fuels are only renewed
over millions of years means that we are collectively
likely to experience peak production moments
(Heinberg, 2007). Unlike the notion of limits of
resource supply, peak production does not refer to
moments when society literally runs out of a given
resource or commodity. Instead peak production
relates to a point after which the rate of supply of
a given resource gradually declines and the cost of
the commodity increases (see Hemmingsen, 2010).
While we will discuss theories of peak produc-
tion in section 2.3, for now it is important to note
that the principles of peak production do not only
apply to fossil fuels such as oil, natural gas and coal.
Nuclear energy, which has been promoted by
some as a long-term replacement of fossil fuels, is
also likely to encounter a peak in its production

Figure 2.2 World total primary energy supply from 1971-2010 by fuel
Note: Mtoe: million tons of oil equivalent.
Source: International Energy Agency, 2012