150
4.2 World Energy Needs
Increasing demand for energy, as populations expand and standards of living rise,
poses a significant challenge to the successful implementation of the Paris Climate
Agreement. Figure 4.2a shows a projection of global energy consumption from
various sources, in units of 10^15 British Thermal Units (BTU),^5 provided by the US
EIA.^6 This agency forecasts a 70 % increase in world energy consumption in 2040,
relative to 2012. We have extrapolated the EIA projections, which stop in 2040, out
(^5) BTU is a measure of heat, or energy. The conversion of BTU to joule, the unit of energy in the
metric system, is usually expressed as 1 BTU = 1055 joule. More information about energy units
is at https://www.aps.org/policy/reports/popa-reports/energy/units.cfm
(^6) This projection is outlined in a May 2016 report entitled International Energy Outlook 2016,
available at https://www.eia.gov/forecasts/ieo/pdf/0484(2016).pdf. A concise summary is at
https://eos.org/articles/high-energy-growth-fossil-fuel-dependence-forecast-through-2040
World Energy Consumption and CO 2 Emissions by Source
History US EIA Projections Extrapolation
Nuclear
Renewables
Coal
Natural Gas
Liquid Fuels
a
5.7%
17.6%
18.9%
28.7%
100 29.2%
200
300
400
500
600
700
800
900
1000
Coal
Natural Gas
Liquid Fuels
RCP 8.5
RCP 4.5
b
34.0%
29.8%
36.2%
1990 2000 2010 2020 2030 2040 2050 2060
10
20
30
40
50
60
70
Energy Consumption (quad BTU)
Gt CO
yr 2
-1
Fig. 4.2 World energy consumption and CO 2 emissions, business as usual. (a) Historical (1990–
2012) and projected (2012–2040) global energy consumption as a function of fuel source, from the
US Energy Information Administration (EIA) and a linear extrapolation of these values out to
2060; (b) CO 2 emissions from the coal, natural gas, and liquid fuel components of world energy
consumption, provided by EIA for 1990–2040 and extrapolated to 2060, compared to emissions
from these sources from RCP 4.5 and RCP 8.5. Numbers to the far right of each wedge are percent
of total, for year 2060. See Methods for further information
4 Implementation