SSP1: Sustainability, in which the world gradually shifts
toward a more sustainable path where the development
happens considering the environmental boundaries.
SSP2: Middle of the road pathway, where social, economic
and technological developments follow a historical trend,
leading to uneven progress among the countries and slowly
attaining sustainable goals.
SSP3: Regional rivalry, where there is increased competitiveness among the countries to attain development and
policies are mostly oriented toward empowering national
securities and local issues.
SSP4: Inequalities, where uneven investments and policies
enhance the inequalities among and within the countries’
increase. Energy demand increases so as the consumption of
carbon as well as low-carbon energy sources.
SSP5: Fossil-fueled development; investment in technological progress and human capital is considered a way to
achieve sustainable development. To cater the increasing
energy demand for achieving economic development, this
world still primarily relies on the fossil fuel resources.
Further details about these SSPs can be found in Calvin
et al. (2016), Fricko et al. (2016), Fujimori et al. (2016),
Hasegawa et al. (2018), Kriegler et al. (2016), van Vuuren
et al. (2016). Emission projections are made using these
SSPs in MAGICC6 (Model for the Assessment of Greenhouse Gas-Induced Climate Change) climate model and are
available as 9 CMIP6 emission scenarios, 4 of which are in
line with the radiative forcings of 2.6, 4.5, 6.0 and
8.5 W m
−2 of RCPs of CMIP5 projections as SSP1-2.6,
SSP2-4.5, SSP4-6.0 and SSP5-8.5. The 5 additional intermediate scenarios cover vivid possibilities of forcing targets
during emergence of these scenarios in future as SSP1-1.9,
SSP3-7.0, SSP3-low near-term climate forcing (LowNTCF),
SSP4-3.4 and SSP5-3.4 Overshoot (OS). Out of these,
SSP3-7.0 and SSP5-8.5 are baseline scenarios, considering
no additional policies are brought into the action to mitigate
GHGs emission other than the existing policies. Considering
the base year as 2015, all these scenarios were then harmonized for smooth transition between the historical data
and these projections and downscaled at country level
(Gidden et al. 2018).
Future projections for India’s GHG emissions, primarily
CO 2 and CH 4 , under different SSPs up to the year 2100 are
shown in Fig. 4.6 where CO 2 emissions span over a large
range of 2–16 Gt-CO 2 yr
−1 under different scenarios and
CH 4 emissions span over 10–90 Mt yr
−1 . The data were
sourced from Riahi et al. (2017). In India, emission projections under four SSPs and a total of 8 scenarios are available,
SSP1-1.9, SSP1-2.6, SSP3-7.0, SSP3-LowNTCF, SSP4-3.4,
SSP4-6.0, SSP5-3.4 OS and SSP5-8.5. SSP1-1.9 is
considered a greener world where energy consumption is
based on more green and renewable energy sources,
restricting the radiative forcing to 1.9 W m
−2 which is in
accordance with the recent Paris Agreement. Trajectories
represent the immediately decreasing CO 2 emissions. In
SSP1-2.6 which also implies a greener world, but the
radiative forcing reaches a level of 2.6 W m
−2 , CO 2 emission tends to decrease, but slightly less than that of SSP1-1.9
in the future due to investment in green energy. India’s CO 2
emissions are projected to peak by the year 2030 and
gradually decrease thereafter. CH 4 emissions are projected to
decrease gradually by the year 2100 to its lowest value
hovering around one-third of present emission. India’s (intended) nationally determined contribution under the Paris
Agreement commits to reduce the emission intensity of its
GDP by 33–35% by 2030 from 2005 level and to achieve
about 40% cumulative electric power installed capacity from
non-fossil fuel-based energy sources by 2030. These SSP
projections are in line with the green and sustainable world
with least GHGs emissions from India as well in such
scenario.
In SSP3-70 and SSP3-LowNTCF, there is a consistent
increase in CO 2 emissions till the end of the century at
almost the same rate. For CH 4 , there is an increase in
SSP3-70 scenario, but in the SSP3-LowNTCF scenario,
where the policies are to reduce the forcing due to
short-lived species, a sharp decrease after 2020 and then a
slight increase are projected till the end of the century. CO 2
increase is attributed to the increased power consumption to
meet the growing energy demand mostly by relying on fossil
fuels and carbon-based energy sources along with the
change in land use, whereas CH 4 emissions are dominated
by agriculture (cultivation and livestock) as of now, also
contributed by energy sector and waste management. Under
the SSP3-70 scenario while CO 2 emission tends to increase
about four times the present emission, increase in CH 4
emission is projected to rapidly increase after 2020 and shall
be tripled by the end of the century; in fact, CH 4 emissions
are seen to reach higher values in this scenario among all the
cases.
SSP4 projection is in the world of unequal development.
In SSP4-6.0, where radiative forcing is restricted to
6 W m
−2 , India’s emission of both CO 2 and CH 4 is projected to peak around the middle of the century, after which
it stabilizes and shows a decreasing tendency around the
year 2060 probably due to the inclusion of investments in
better technologies and sustainable energy sources in the
future. While CO 2 emissions tend to stabilize toward the end
of this century around today’s emission rate, CH 4 emissions
are on the higher side, even after an anticipated decline in
emission in the latter half of the century. In SSP4-3.4, CO 2
86
S. Chakraborty et al.
toward a more sustainable path where the development
happens considering the environmental boundaries.
SSP2: Middle of the road pathway, where social, economic
and technological developments follow a historical trend,
leading to uneven progress among the countries and slowly
attaining sustainable goals.
SSP3: Regional rivalry, where there is increased competitiveness among the countries to attain development and
policies are mostly oriented toward empowering national
securities and local issues.
SSP4: Inequalities, where uneven investments and policies
enhance the inequalities among and within the countries’
increase. Energy demand increases so as the consumption of
carbon as well as low-carbon energy sources.
SSP5: Fossil-fueled development; investment in technological progress and human capital is considered a way to
achieve sustainable development. To cater the increasing
energy demand for achieving economic development, this
world still primarily relies on the fossil fuel resources.
Further details about these SSPs can be found in Calvin
et al. (2016), Fricko et al. (2016), Fujimori et al. (2016),
Hasegawa et al. (2018), Kriegler et al. (2016), van Vuuren
et al. (2016). Emission projections are made using these
SSPs in MAGICC6 (Model for the Assessment of Greenhouse Gas-Induced Climate Change) climate model and are
available as 9 CMIP6 emission scenarios, 4 of which are in
line with the radiative forcings of 2.6, 4.5, 6.0 and
8.5 W m
−2 of RCPs of CMIP5 projections as SSP1-2.6,
SSP2-4.5, SSP4-6.0 and SSP5-8.5. The 5 additional intermediate scenarios cover vivid possibilities of forcing targets
during emergence of these scenarios in future as SSP1-1.9,
SSP3-7.0, SSP3-low near-term climate forcing (LowNTCF),
SSP4-3.4 and SSP5-3.4 Overshoot (OS). Out of these,
SSP3-7.0 and SSP5-8.5 are baseline scenarios, considering
no additional policies are brought into the action to mitigate
GHGs emission other than the existing policies. Considering
the base year as 2015, all these scenarios were then harmonized for smooth transition between the historical data
and these projections and downscaled at country level
(Gidden et al. 2018).
Future projections for India’s GHG emissions, primarily
CO 2 and CH 4 , under different SSPs up to the year 2100 are
shown in Fig. 4.6 where CO 2 emissions span over a large
range of 2–16 Gt-CO 2 yr
−1 under different scenarios and
CH 4 emissions span over 10–90 Mt yr
−1 . The data were
sourced from Riahi et al. (2017). In India, emission projections under four SSPs and a total of 8 scenarios are available,
SSP1-1.9, SSP1-2.6, SSP3-7.0, SSP3-LowNTCF, SSP4-3.4,
SSP4-6.0, SSP5-3.4 OS and SSP5-8.5. SSP1-1.9 is
considered a greener world where energy consumption is
based on more green and renewable energy sources,
restricting the radiative forcing to 1.9 W m
−2 which is in
accordance with the recent Paris Agreement. Trajectories
represent the immediately decreasing CO 2 emissions. In
SSP1-2.6 which also implies a greener world, but the
radiative forcing reaches a level of 2.6 W m
−2 , CO 2 emission tends to decrease, but slightly less than that of SSP1-1.9
in the future due to investment in green energy. India’s CO 2
emissions are projected to peak by the year 2030 and
gradually decrease thereafter. CH 4 emissions are projected to
decrease gradually by the year 2100 to its lowest value
hovering around one-third of present emission. India’s (intended) nationally determined contribution under the Paris
Agreement commits to reduce the emission intensity of its
GDP by 33–35% by 2030 from 2005 level and to achieve
about 40% cumulative electric power installed capacity from
non-fossil fuel-based energy sources by 2030. These SSP
projections are in line with the green and sustainable world
with least GHGs emissions from India as well in such
scenario.
In SSP3-70 and SSP3-LowNTCF, there is a consistent
increase in CO 2 emissions till the end of the century at
almost the same rate. For CH 4 , there is an increase in
SSP3-70 scenario, but in the SSP3-LowNTCF scenario,
where the policies are to reduce the forcing due to
short-lived species, a sharp decrease after 2020 and then a
slight increase are projected till the end of the century. CO 2
increase is attributed to the increased power consumption to
meet the growing energy demand mostly by relying on fossil
fuels and carbon-based energy sources along with the
change in land use, whereas CH 4 emissions are dominated
by agriculture (cultivation and livestock) as of now, also
contributed by energy sector and waste management. Under
the SSP3-70 scenario while CO 2 emission tends to increase
about four times the present emission, increase in CH 4
emission is projected to rapidly increase after 2020 and shall
be tripled by the end of the century; in fact, CH 4 emissions
are seen to reach higher values in this scenario among all the
cases.
SSP4 projection is in the world of unequal development.
In SSP4-6.0, where radiative forcing is restricted to
6 W m
−2 , India’s emission of both CO 2 and CH 4 is projected to peak around the middle of the century, after which
it stabilizes and shows a decreasing tendency around the
year 2060 probably due to the inclusion of investments in
better technologies and sustainable energy sources in the
future. While CO 2 emissions tend to stabilize toward the end
of this century around today’s emission rate, CH 4 emissions
are on the higher side, even after an anticipated decline in
emission in the latter half of the century. In SSP4-3.4, CO 2
86
S. Chakraborty et al.