Glossary, Acronyms and Chemical SymbolsAnnex I
example, one chooses different values for speciﬁc parameters and re-
runs a given model to assess the impact of these changes on model
Sequestration: The uptake (i. e., the addition of a substance of con-
cern to a reservoir) of carbon containing substances, in particular car-
bon dioxide (CO
), in terrestrial or marine reservoirs. Biological seques-
tration includes direct removal of CO
from the atmosphere through
land-use change (LUC), afforestation, reforestation, revegetation, car-
bon storage in landﬁlls, and practices that enhance soil carbon in agri-
culture (cropland management, grazing land management). In parts of
the literature, but not in this report, (carbon) sequestration is used to
refer to Carbon Dioxide Capture and Storage (CCS).
Shadow pricing: Setting prices of goods and services that are not, or
are incompletely, priced by market forces or by administrative regula-
tion, at the height of their social marginal value. This technique is used
in cost-beneﬁt analysis (CBA).
Shared socio-economic pathways (SSPs): Currently, the idea of
SSPs is developed as a basis for new emissions and socio-economic
scenarios. An SSP is one of a collection of pathways that describe
alternative futures of socio-economic development in the absence of
climate policy intervention. The combination of SSP-based socio-eco-
nomic scenarios and Representative Concentration Pathway (RCP)-
based climate projections should provide a useful integrative frame
for climate impact and policy analysis. See also Baseline / reference, Cli-
mate scenario, Emission scenario, Mitigation scenario, Scenario, SRES
scenarios, Stabilization, and Transformation pathway.
Short-lived climate pollutant (SLCP): Pollutant emissions that have
a warming inﬂuence on climate and have a relatively short lifetime in
the atmosphere (a few days to a few decades). The main SLCPs are
black carbon (BC) (‘soot’), methane (CH
) and some hydroﬂurorcar-
bons (HFCs) some of which are regulated under the Kyoto Protocol.
Some pollutants of this type, including CH
, are also precursors to the
formation of tropospheric ozone (O
), a strong warming agent. These
pollutants are of interest for at least two reasons. First, because they
are short-lived, efforts to control them will have prompt effects on
global warming — unlike long-lived pollutants that build up in the
atmosphere and respond to changes in emissions at a more sluggish
pace. Second, many of these pollutants also have adverse local impacts
such as on human health.
Sink: Any process, activity or mechanism that removes a greenhouse
gas (GHG), an aerosol, or a precursor of a GHG or aerosol from the
Smart grids: A smart grid uses information and communications tech-
nology to gather data on the behaviours of suppliers and consumers in
the production, distribution, and use of electricity. Through automated
responses or the provision of price signals, this information can then
be used to improve the efﬁciency, reliability, economics, and sustain-
ability of the electricity network.
Smart meter: A meter that communicates consumption of electricity
or gas back to the utility provider.
Social cost of carbon (SCC): The net present value of climate dam-
ages (with harmful damages expressed as a positive number) from one
more tonne of carbon in the form of carbon dioxide (CO
on a global emissions trajectory over time.
Social costs: See Private costs.
Socio-economic scenario: A scenario that describes a possible future
in terms of population, gross domestic product (GDP), and other socio-
economic factors relevant to understanding the implications of climate
change. See also Baseline / reference, Climate scenario, Emission sce-
nario, Mitigation scenario, Representative Concentration Pathways
(RCPs), Scenario, Shared socio-economic pathways, SRES scenarios,
Stabilization, and Transformation pathway.
Solar energy: Energy from the sun. Often the phrase is used to mean
energy that is captured from solar radiation either as heat, as light that
is converted into chemical energy by natural or artiﬁcial photosynthe-
sis, or by photovoltaic panels and converted directly into electricity.
Solar Radiation Management (SRM): Solar Radiation Manage-
ment refers to the intentional modiﬁcation of the earth’s shortwave
radiative budget with the aim to reduce climate change according to a
given metric (e. g., surface temperature, precipitation, regional impacts,
etc.). Artiﬁcial injection of stratospheric aerosols and cloud brightening
are two examples of SRM techniques. Methods to modify some fast-
responding elements of the longwave radiative budget (such as cirrus
clouds), although not strictly speaking SRM, can be related to SRM.
SRM techniques do not fall within the usual deﬁnitions of mitigation
and adaptation (IPCC, 2012, p.2). See also Carbon Dioxide Removal
(CDR) and Geoengineering.
Source: Any process, activity or mechanism that releases a green-
house gas (GHG), an aerosol or a precursor of a GHG or aerosol into
the atmosphere. Source can also refer to, e. g., an energy source.
Spill-over effect: The effects of domestic or sector mitigation mea-
sures on other countries or sectors. Spill-over effects can be positive
or negative and include effects on trade, (carbon) leakage, transfer of
innovations, and diffusion of environmentally sound technology and
SRES scenarios: SRES scenarios are emission scenarios developed by
Nakićenović and Swart (2000) and used, among others, as a basis for
some of the climate projections shown in Chapters 9 to 11 of IPCC
(2001) and Chapters 10 and 11 of IPCC (2007) as well as WGI AR5. The