Harald Heinrichs · Pim Martens Gerd Michelsen · Arnim Wiek Editors

Fig. 19.3
Final energy (GJ) per capita versus cumulative population for 11 world regions sorted 
by declining per capita energy use (with final energy use disaggregated by sector and total, colour 
bars
) and final energy per capita for 137 countries in 2005 (black, solid line). Dashed horizontal 
line
shows the average final energy per capita, which indicates that approximately 1.5 billion 
people are above and 5.5 billion below that level (Source: GEA 
2012
, 36. Reproduced with per-
mission from the International Institute for Applied Systems Analysis (IIASA))
19 Sustainable Energy Systems

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236
In this context the UN has launched the “sustainable energy for all” initiative 
(
http://www.se4all.org/
) which aims at delivering accessible, efficient and renewable 
energy to as many people as possible as a major initiative to achieve the eight 
Millennium Development Goals (IEA
2011
). Energy will also be important in the 
context of future Sustainable Development Goals (Chap.
22
). 
3.2 Climate Change and the Environment
Energy use today contributes to about 80 % of CO
2
and 30 % of CH
4
emissions, 
which are together the main greenhouse gases causing global warming and related 
climate change. Cumulative historic CO
2
emissions have tripled from 1970 (~420 
GtCO
2
since 1750) to 2010 (~1300 GtCO
2
since 1750) (IPCC
2014
). Energy sys-
tems also emit many other pollutants (e.g. SO
x
, NO
x
, heavy metals, particulate mat-
ter and organic compounds), and they are relevant for land use and degradation, e.g. 
for deforestation, for mining of energy resources or for energy infrastructures, as 
well as for water consumption through, e.g. use of cooling water for power plants 
and industrial installations (see Fig. 
19.4
).
Energy use is thus the major single factor that drives the emissions of anthropo-
genic greenhouse gases and emissions continue to grow. Despite all incremental 
improvements through higher shares of renewable energy use and improved technolo-
gies, the environmental burden from energy use continues to increase at high speed.