THE ANTHROPOCENE - Plastics and Environmental Sustainability - page 21

Figure 1.8 Estimated embodied energy (left) and carbon emissions (right)
of classes of building materials globally consumed in 2011. See
http://www.circularecology.com/ice-database.html .
Source: Calculations based on data in Hammond and Jones (2011).
1.2.2 Metal Resources
Metal resources are nonrenewable and their long-term availability depends
on the known reserves and the cost of extraction. With some metals such
as uranium, the fraction of the oxide present in earth is approximately
0.1-0.2%. This means that a large area of earth has to be processed to
extract the metal. This would result in relatively larger environmental
impact compared to producing a metal such as aluminum where the ore
is 30-50% oxide. Richards (2009) reported the world reserves of selected
industrially important metals. These numbers ( Table 1.2 ) are based on the
current rate of use and can change in the future because of accelerated use
and the discovery of new reserves.