Energy and Electricity - Introduction to Carbon Capture and Sequestration - page 10

one wedge: 25 billion tonnes over 50 years

1 billion tonnes/year

50 years

14

7

0

2006 2056 2106

1956

Year

Figure 1.2.3 Reducing CO 2 emissions
Past (dark blue line) and future worldwide carbon emissions. The brown line gives the
business as usual scenario in which we assume that our future energy needs are met
using the same resources we use today. The concept of wedges is based on the idea that
we can achieve a total emission reduction of 7 billion tonnes of carbon per year by imple-
menting seven technologies. In the figure, each wedge represents the ramping up of a
CO 2 abatement technology, over a period of fifty years, to a total of 1 billion tonnes of
CO 2 avoided per year. Overall, the seven wedges represent a total emission reduction of
175 Gt C between 2006 and 2056. Figure adapted from Pacala and Socolow [1.4].

Energy and population

Arguably the single most important issue underlying the rise in energy
consumption is the growth of the population. It is no surprise that at pre-
sent there exist large disparities in annual energy consumption per capita
around the globe. Figure 1.2.6 illustrates these large differences in
energy consumption, and hence carbon emission per capita, between
the different countries [1.6]. What future emissions might look like can be
extrapolated from Movie 1.2.1 , which shows how emission correlates
with per capita income [1.7].