Energy and Electricity - Introduction to Carbon Capture and Sequestration - page 8

9000

Solids
Liquids
Gases
Flaring
Cement
Total

6000

3000

0

1750 1815 1880 1945 2010

Ye a r

Figure 1.2.2 Historical CO 2 emission from different sources
Globally, liquid and solid fuels accounted for 76.3% of the emissions from fossil-fuel
burning and cement production in 2007. Combustion of gas fuels (e.g., natural gas)
accounted for 18.5% (1551 million metric tonnes of carbon) of the total emissions from
fossil fuels in 2007, reflecting a gradually increasing global utilization of natural gas.
Emissions from cement production (377 million metric tonnes of carbon in 2007) have
more than doubled since the mid 1970s and now represent 4.5% of global CO 2 releases
from fossil-fuel burning and cement production. Gas flaring, which accounted for
roughly 2% of global emissions during the 1970s, now accounts for less than 1% of
global CO 2 release. The units are in mass of carbon instead of mass of CO 2 . To convert
these estimates to units of CO 2 , multiply by 3.667. Figure adapted from the Carbon
Dioxide Information Analysis Center [1.3].

Question 1.2.1 Renewables and Energy

What is the percentage of renewable energy in our current energy con-
sumption? How is this percentage divided between the different sources of
renewable energies? What was this percentage in 1800?

Future CO 2 production
In this chapter we focus on the production of CO 2 . In the next two chap-
ters we discuss the relation between CO 2 levels in the atmosphere and
the average temperature. In our discussion about future CO 2 production,