2. ➔ INTRODUCTION
➔ SPECIAL REPORT ON EMISSION SCENARIOS
➔ SHARED SOCIO-ECONOMIC PATHWAYS
➔ CONCLUSION
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3. INTRODUCTION
● Greenhouse gases absorb and emits radiant energy at thermal infrared wavelengths, causing
greenhouse effect.
● The main greenhouse gases are carbon dioxide, water vapour, methane, nitrous oxide and ozone.
● Emission scenarios of greenhouse gases are hypothetical pathways that describe different
possible futures of greenhouse gas emissions based on different assumptions about socio-
economic and technological factors.
● Scenarios are used to explore the potential impacts of greenhouse gas emissions.
● Emission scenarios are used to develop strategies to mitigate and adapt to the impacts of climate
change.
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4. ● Scenarios are developed using computer models that simulate the relationships between various
socio-economic and technological factors and greenhouse gas emissions.
● The factors include population growth, economic development, energy use, land use, and
technological innovation.
● Emission scenarios are often expressed in terms of different scenarios that describe the key
assumptions and drivers of greenhouse gas emissions.
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5. SPECIAL REPORT ON EMISSION SCENARIOS (SRES)
● The Special Report on Emissions Scenarios is a report by Intergovernmental Panel on Climate
Change (IPCC) that was published in 2000.
● The greenhouse gas emissions scenarios have been used to make projections of possible future
climate change.
● The SRES scenarios are "baseline" scenarios.
● Do not take into account any current or future measures to limit greenhouse gas (GHG) emissions.
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6. ❖ Purpose
● Future greenhouse gas emissions are the product of very complex dynamic systems
● Determined by demographic development, socio-economic development, and technological
change.
● Scenarios are alternative images of how the future might unfold.
● Assist in climate change analysis, including climate modeling and the assessment of impacts,
adaptation, and mitigation.
● The possibility that any single emissions path will occur is highly uncertain.
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7. ● Climate models are run against scenarios because projections of climate change depend heavily
upon future human activity.
● There are 40 different scenarios.
● Assumptions about future technological and economic development are made for each scenario.
● Include an increase in the consumption of fossil fuels.
● Shared Socioeconomic Pathways (SSPs) is one of the most widely recognized emission
scenario families.
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8. ● Emissions scenarios are organized into families, which contain scenarios that are similar to each
other in some respects.
● IPCC assessment report projections for the future are often made in the context of a specific
scenario family.
● According to the IPCC, all SRES scenarios are considered "neutral".
● None of the SRES scenarios project future disasters or catastrophes.
● The scenarios are not described by the IPCC as representing good or bad pathways of future
social and economic development.
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9. ● Scenario families contain individual scenarios with common themes.
● The six families of scenarios discussed in the IPCC's Third Assessment Report (TAR) and
Fourth Assessment Report (AR4) are A1FI, A1B, A1T, A2, B1, and B2.
● Scenario descriptions are based on those in AR4, which are identical to those in TAR.
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10. Fig 1: Family of SRES scenarios and their storylines
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11. A1
● The A1 scenarios are of a more integrated world.
● The A1 family of scenarios is characterized by:
○ Rapid economic growth.
○ The quick spread of new and efficient technologies.
● There are subsets to the A1 family based on their technological emphasis:
○ A1FI - An emphasis on fossil-fuels (Fossil Intensive).
○ A1B - A balanced emphasis on all energy sources.
○ A1T - Emphasis on non-fossil energy sources.
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12. A2
● The A2 scenarios are of a more divided world.
● The A2 family of scenarios is characterized by:
○ A world of independently operating, self-reliant nations.
○ Continuously increasing population.
○ Regionally oriented economic development.
○ High emissions.
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13. B1
● The B1 scenarios are of a world more integrated, and more ecologically friendly.
● The B1 scenarios are characterized by:
○ Rapid economic growth towards a service and information economy.
○ Reductions in material intensity.
○ An emphasis on global solutions to economic, social and environmental stability.
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14. B2
● The B2 scenarios are of a world more divided, but more ecologically friendly.
● The B2 scenarios are characterized by:
○ Continuously increasing population, but at a slower rate than in A2.
○ Emphasis on local rather than global solutions.
○ Intermediate levels of economic development.
○ Less rapid and more fragmented technological change than in A1 and B1.
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15. SHARED SOCIO-ECONOMIC PATHWAYS
● Shared Socioeconomic Pathways (SSPs) are scenarios of projected socioeconomic global
changes up to 2100.
● Used to derive greenhouse gas emissions scenarios with different climate policies.
● The scenario family include:
○ SSP1: Sustainability (Taking the Green Road)
○ SSP2: Middle of the Road
○ SSP3: Regional Rivalry (A Rocky Road)
○ SSP4: Inequality (A Road divided)
○ SSP5: Fossil-fueled Development (Taking the Highway)
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16. ● The SSPs provide narratives describing alternative socio-economic developments.
● Provide data accompanying the scenarios on national population, urbanization and GDP (per
capita) in terms of quantitative elements.
● Quantified with various Integrated Assessment Models (IAMs), to explore possible future
pathways both with regards to socioeconomic and climate pathways.
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17. ❖ SSP Family
● SSP1: Sustainability :
○ Assumes a strong focus on sustainable development, with a shift towards renewable
energy sources, increased energy efficiency, and low-carbon lifestyles.
○ Result in the lowest levels of greenhouse gas emissions and the most ambitious mitigation
targets.
● SSP2: Middle of the Road :
○ Assumes a continuation of current trends in population growth, economic development,
and energy use.
○ Result in moderate levels of greenhouse gas emissions and a more gradual transition
towards low-carbon energy systems.
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18. ● SSP3: Regional Rivalry:
○ Assumes a world characterized by fragmented regional interests, limited international
cooperation, and high levels of inequality.
○ Result in the highest levels of greenhouse gas emissions and the least ambitious
mitigation targets.
● SSP4: Inequality:
○ Assumes a world characterized by high levels of inequality, slow economic growth, and
limited technological progress.
○ Result in moderate levels of greenhouse gas emissions.
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19. ● SSP5: Fossil-Fueled Development:
○ This family assumes a continuation of the current fossil-fuel-based energy system.
○ Result in the highest levels of greenhouse gas emissions and the least ambitious
mitigation targets.
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Fig 3: SSPs mapped in the challenges to mitigation/adaptation space
21. ❖ Implications
● Climate change scenarios
● Policy-making
● Societal transformation
● Equity and justice
● Business planning
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22. CONCLUSION
● Greenhouse gas emissions are a significant contributor to climate change.
● The emission scenarios are based on different assumptions about future emissions, which are
influenced by factors such as population growth, economic development, and technological
advancements.
● Socio-economic pathways (SEPs) are scenarios that describe possible futures based on different
economic and social development trajectories.
● SEPs take into account the complexity of the interactions between economic, social, and
environmental systems.
● SEPs allow for a comprehensive analysis of the potential consequences of different policy
choices.
● It is crucial to take proactive steps to reduce emissions and transition to a more sustainable and
resilient society.
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