Main Content

601
This index should be cited as: IPCC, 2018: Index. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening
the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte, V., P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan,
R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, and T. Waterfield (eds.)]. In Press.

Note: [*] indicates the term also appears in the
Glossary. Italicized page numbers denote tables,
figures and boxed material. Bold page numbers
indicate main discussion of topics. Supplementary
Material is listed by section number, for example,
1.SM.3, 2.SM.1.3.4.
1.5°C pathways*, 12–17, 51, 59–64, 93–174,
265–271, 278, 320, 1.SM.4, 1.SM.6
assumptions, 95, 98, 109–112
carbon dioxide removal (CDR)* in, 17, 21, 95, 96,
118–125, 180, 277, 316

CO2 emissions, 1.SM.6
definition, 51, 53, 59–61
demand-side mitigation and, 97, 460–461
emissions and, 5, 6, 12, 13, 14–15, 18, 51, 95–96,
112, 1.SM.6
emissions, benchmark indicators for
sectoral changes in, 4.SM.1
emissions evolution in, 115–118, 117, 119
feasibility*, 18–19, 52, 56, 71–72, 380–386
four categories of, 59–61, 62, 63
future emissions in, 96, 104–107
impediments to, 93, 95, 110
implications of, 265–271
investments and economics, 16, 95–96, 150–151,
152–155, 264–265
key characteristics, 112–114, 129
knowledge gaps, 388–390
mitigation and adaptation options*, 110–112,
316–317
mitigation measures, 14–15, 19–21, 51–52, 110–112
model pathways, 12, 14–15, 278
multiple strategies for, 157, 469
near-term action, implications of, 126–129, 128
one-in-two to two-in-three chance (of reaching
limit) in, 60, 63, 113
overview of, 108–129, 129
pathway archetypes, 99–100, 100, 112–113, 113
pathways remaining below 1.5°C, 100,
113–114, 160
pathways temporarily exceeding 1.5°C, 100,
113–114, 160
policies, 112, 148–150
remaining carbon budget*, 12, 96, 104–107, 108
scenarios, 98–100, 100
strengthening the global response, 18–23, 70–75,
313–443
sustainable development and, 19–23, 20–21, 98,
156–157, 156, 448–449, 463–472, 465
sustainable development pathways, 64, 448–449,
466–472, 469, 479–480
synergies and trade-offs, 18–21, 20–21, 316, 391
system/sector transitions, 14–15, 15–16,
323–349
time frame for mitigation, 95–96
transformations, 129–148, 322–323, 466
transitions, speed and scale of, 320, 320, 322–323
See also Pathways
1.5°C warmer worlds*, 4–6, 274–281
commonalities in, 277
definition, 53
energy supply and demand in (FAQ), 161, 162
equity and, 54–55, 451–453
impacts in, 7–10, 177–179, 319
importance of adaptation in (FAQ), 396–397, 397
key questions, 274–277
knowledge base for, 52, 53–56
poverty, equality, and equity implications, 451–453
projected climatic changes, 7–10, 186–188, 188, 189
projected risks and impacts, 7–10, 11, 51,
175–311
risks, vs. 2°C worlds, 5, 7–9, 11, 177–181, 277
storyline of this report, 77–78, 78
storylines of, 277
sustainable development and, 18–23, 55–56, 447
temperature in, 283
time frame for mitigation, 277, 278
variation in, 177, 277, 278
watershed management in, 356
See also Global warming of 1.5°C
2030
emissions gap, 358
emissions levels in, 18, 95, 114
2030 Agenda for Sustainable Development*,
56, 73, 469, 477
See also Sustainable Development Goals
A
Acceptability of policy or system change*,
22, 368–369
Adaptability. See Adaptive capacity
Adaptation*, 5, 10
bottom-up approaches, 317, 368
community-based, 315, 330, 384, 458
definition, 51, 70, 396
ecosystem-based, 386, 457–458
FAQ on, 396–397, 397
feasibility, 380, 381, 385
finance, 21–22, 379, 456
implementing, 51, 315, 383–386
importance of, 396–397, 397
infrastructure investments, 21
integration with mitigation and sustainable
development, 75–76, 448, 467
knowledge gaps, 388–391
levels of, 51
local participation, 456
maladaptation, 19, 386, 396
in Mekong River basin, 239–240
place-specific, 447, 458
potential for, 247–250
rate of temperature change and, 178
risk reduction and, 5, 10
sea level rise and, 10, 457
socio-economic challenges to, 110
specific sectors, 10
sustainable development and, 19, 447, 456–459
synergies, 18–19, 391, 447, 475
synergies with mitigation, 386–387, 475,
4.SM.4.5.1, 4.SM.5.2
transformational, 5, 315, 322–323, 384, 397,
456–457
Adaptation behaviour*, See Human behaviour
Adaptation limits*, 10, 70, 454–456
examples of, 455
hard limits, 70, 455
residual risks and, 454–455
for Small Island Developing States, 235
soft limits, 70, 455
Adaptation options*, 10, 19, 316–317, 319,
336–337
in agriculture, 70, 315, 457
cost-effectiveness, 316
education and learning, 337, 456
enabling conditions*, 4.SM.2
energy system transitions, 4.SM.4.3.1
feasibility, 381, 384–386, 385,
4.SM.4.3.1-4.SM.4.3.5
industrial system transitions, 4.SM.4.3.4
land and ecosystem transitions, 4.SM.4.3.2
overarching, 336–337, 338, 385, 389, 4.SM.4.3.5
supporting transitions, 336–337, 338
sustainable development and, 457–458
synergies, 18, 19
urban, 10, 70, 263, 340–341, 384–386, 385
urban and infrastructure transitions, 4.SM.4.3.3
Adaptation pathways*, 64, 70, 396, 458–459
place-specific, 458
Adaptive capacity*,
enhancing, 316, 319, 456–457
factors affecting, 69
limits to, 10
sustainable development and, 447
Adaptive governance. See Governance
Aerosols*, 12, 65, 118, 120, 267–268
aerosol cooling, 96, 267–268
knowledge gaps, 157
precursors, 98, 102–103, 118, 157
radiative forcing, 102–103
See also Black carbon
Afforestation*, 17, 21, 96, 121, 266, 270, 316, 343
co-benefits, 316
constraints, 316
FAQ, 394, 395
incentivization of, 147
land requirements, 125, 126, 265, 266, 269,
270, 316
trade-offs, 269
AFOLU. See Agriculture, forestry and other land-use
Africa
Fybnos and succulent Karoo biomes, 260, 261
Limpopo Watercourse Commission, 356
Sahel, 180, 236, 259, 261, 262–263
Southern Africa, 260, 261
tipping points*, 262–263, 264
West Africa and the Sahel, 259, 261, 264
West African monsoon, 262–263, 264
Agreement*. See Confidence; Evidence; Likelihood
Agriculture
adaptation options*, 70, 315, 457
agroforestry, 328, 384
Index
Index
603
climate-smart agriculture*, 457, 467
conservation agriculture*, 267, 327, 384, 459
crop yields/productivity, 9, 11, 145, 145, 147,
179, 236–237, 252, 259, 263, 264, 267, 316, 327,
452, 3.SM.3.3.5
emissions, 12, 14, 95, 96, 116–118, 147, 147, 157,
265, 315–316
energy crops, 16, 97
intensification of, 266–267, 327
irrigation, 201, 215, 267, 267, 315, 328, 384, 466
land for, 16, 97, 112, 146, 327–329
livelihoods, 55, 315, 447
mitigation potential, 316
peri-urban, 316
risk reduction, 456
technological innovation and, 329, 370
tipping points*, 263, 264
transformational adaptation in, 384
transitions, 315–316
water-energy-food (WEF) nexus, 386–387
Agriculture, forestry and other land-use (AFOLU),
144–148, 463
CDR and, 17, 121, 144–145
drivers of changes in, 145–146
emissions, 14–15, 114, 118, 268
mitigation options*, 462–463
policy assumptions, 145–146
projections for, 17
Agroforestry, 328, 384
Air pollution/quality*, 157, 241, 250, 267, 316, 464
Albedo*, 70, 267
Algae, as bioenergy source, 111–112
Alpine regions, 259, 261
Amazon, 340
tropical forest, 221, 263, 340
Ammonia (NH3) emissions, 96
Anomalies*
global mean surface temperature, 183, 210
soil moisture*, 198, 199, 200
Antarctic ice sheet, 7, 178, 208–209, 257, 258, 271,
282
Antarctic sea ice, 206, 225
Anthropocene*, 52, 53, 54, 75
as boundary concept for 1.5°C warmer worlds, 54
geological dimension of, 54
Anthropogenic emissions*, 5, 95
recent trends, 1.SM.7
Appliances, energy-efficient, 316, 331, 460, 461
Aquaculture, 8, 9, 237–238
hypoxia and, 224
production, 237–238
risks for, 228
AR5. See IPCC Fifth Assessment Report (AR5)
Arctic region, 258–259, 338–339, 452, 3.SM.3.3.5
adaptation in, 339
economic effects of climate change, 339
ecosystems, 9, 11, 53, 220
as hotspot, 258, 261, 262, 270, 338
indigenous peoples, 9, 339
land regions, 259, 261
risks for, 9, 53, 251, 252, 253, 452
tipping points*, 262, 264
warming in, 4
See also Arctic sea ice
Arctic sea ice, 8, 205–206, 209, 254
beyond end of century, 270

fisheries and, 224–225
as hotspot and tipping point, 258, 261, 262, 270
projected changes, 205, 212, 254
sea-ice free summers, 8, 178, 205, 206, 254
temperature overshoot and, 8, 178, 206
Asian monsoon, 262, 264
Assessment frameworks, 75–76
climate models and simulations, 76
confidence, uncertainty, and risk, 77
cost-benefit analysis*, 76
detection and attribution, 76
knowledge sources and evidence, 75–76
methodologies, 76
risk assessment*, 183–186
Atlantic Meridional Overturning Circulation
(AMOC), 205, 223, 257
Atlantic Multi-Decadal Oscillation (AMO), 201
Atmosphere-ocean general circulation model
(AOGCM). See Climate models
Attribution. See Detection and attribution
Avoided impacts, 18, 68, 183, 253–265, 447
aggregated avoided impacts, 253–258
hotspots, 258–260, 261
poverty and inequality implications, 452–453, 453
Reasons for Concern, 253–259
reduced risks, 452–453, 453, 455
regional tipping points, 262–263, 264
sustainable development
implications, 452–453, 453
B
Baseline period. See Reference period
Batteries, 325
Behavioural change. See Human behaviour
Beijing, peak car use, 376
Bhutan, national goals, 387
Bio-based feedstocks, 315, 335–336, 335
Bio-technologies, 319
Biochar*, 121, 268, 270, 345
Biodiversity*, 8, 256–257
adaptation limits*, 455
Aichi targets, 266
CDR and, 265, 266, 269
impacts and risks at 1.5°C vs. 2°C, 8, 179, 256–257
management, 10
Bioenergy*, 12, 17, 97, 111–112, 124, 131, 324–325
carbon intensity of, 324–325
crops, 147
emissions increase with, 96
IAMs/modelling, 124, 2.SM.1.2.4
land use for, 19, 146, 147, 265, 269, 343
risks of implementing, 125
sugarcane for bioethanol in Brazil, 371
trade-offs, 97
water use and, 464–466
Bioenergy with carbon dioxide capture and
storage (BECCS)*, 17, 121, 268–270, 316,
342–343, 394, 395
in IAMs, 124
land requirements, 125, 126, 180, 265–266
net zero emissions and, 135
pathways with, 14–15, 17, 96, 180
risks, 125, 268–270
uncertainties, 158
Bioethanol, 371
Biofuel*, 269, 324–325
Biomass*, 131, 132–133, 138, 269, 324
Biome shifts, 216, 217, 247, 250, 256–257
Fybnos and succulent Karoo biomes, 260, 261
Bivalve molluscs, 180, 227, 228, 237, 238, 248,
3.SM.3.2.5, 3.SM.3.2.11
Black carbon (BC)*, 12, 13, 96, 118, 120, 316,
341–342
main characteristics of, 342
reducing emissions of, 341–342
warming impact, 66
Blue carbon*, 330, 462
Bolivian Altiplano, 458
Boreal forests, 8, 263, 264
Bottom-up approaches, 317, 368
Brazil
bioethanol in, 371
National Adaptation Plan, 340
Buen Vivir, 480
Buildings, 15–16, 139, 140–142, 316
building codes, 332, 339, 377
decarbonization of energy supply, 316
decarbonization of investments, 378
electrification, 141
energy efficiency and, 332, 339, 377, 460
energy supply/use in, 139, 140–142, 141, 331
heating and cooling demand, 141–142, 331
long-lived infrastructure, 142
low-emission, 317, 460
technological innovations, 370
transitions, speed and scale of, 320
Burden sharing*, 380, 470
C
Cancun Agreement, 79, 353
Car use
peak car use, 376
pricing policies and use reductions, 366
Carbon budget*, 12, 96, 104–107
in 1.5°C pathways, 113–114
remaining carbon budget*, 12, 24, 96, 104–107, 108
remaining carbon budget*, assessment methods,
104–107, 2.SM.1.1.2
total, 24
uncertainties, 12, 96, 106, 108
Carbon cycle*, 96, 103, 157
inertia, 107
oceans and, 257–258
terrestrial, 219, 220
uncertainties, 347
Carbon dioxide (CO2)*
cumulative emissions, 6, 12, 62, 67, 96, 105, 114,
123, 126–127, 127
Index
Index
604
emissions reductions, 18, 95, 96
net emissions, 12–17, 13, 14–15, 114, 116, 119
net zero emissions, 5, 12, 24, 95, 107, 116
permafrost release of, 104
sector-specific emissions, 119
time scales of warming due to, 64
Carbon dioxide capture and storage (CCS)*, 14, 15,
97, 134–136, 136, 268, 277, 315
deployment in 1.5°C and 2°C pathways, 134–136,
136
direct air carbon dioxide capture and storage
(DACCS)*, 17, 125
fossil fuels with CCS, 97, 135
in industry sector, 335, 336
in power sector, 326–327
uncertainties, 136
See also Bioenergy with carbon dioxide capture
and storage (BECCS)
Carbon dioxide capture and utilisation (CCU)*,
15, 335, 336
Carbon dioxide capture, utilisation and storage
(CCUS). See Carbon dioxide capture and utilisation
(CCU)
Carbon dioxide removal (CDR)*, 17, 70, 118–125,
268–270, 342–346, 4.SM.4.2.5
in 1.5°C pathways*, 17, 21, 95, 96, 111, 114,
118–125, 122, 180, 265, 277, 316
AFOLU sector, 17, 121
co-benefits, 121, 266
comparison of removal options, 270
costs, 344, 4.SM.3
cross-cutting issues, 347
definition, 24, 70
deployment at scale, 17, 70, 96, 114, 121–124,
122, 180, 265–266, 269–270, 343, 4.SM.3
deployment potential, 344
design and implementation of, 21, 448
ethical aspects, 347
FAQ on, 394, 395
feasibility, 17, 121, 269, 316, 343, 383, 4.SM.4.2.5
governance and, 17, 347
key messages, 270
knowledge gaps, 158, 390
land-based, 268–270
land footprint of, 125, 126, 180, 265–266, 269,
270, 343
limitations of, 96
in model pathways, 12, 14–15
net negative emissions, 96, 114, 118
ramp-up rates for, 119, 123
reducing dependence on, 19, 149, 180, 277
risks of, 96, 114, 125, 265–266, 344
role of, 17, 21, 96, 111, 114, 122–123
side effects, 344, 4.SM.3
sustainability and, 21, 96, 114, 124–125
Sustainable Development Goals and, 448, 462
trade-offs, 21, 96, 462
types of measures employed, 17, 70, 96, 121,
125, 265, 268, 270, 316, 342–346, 394
uncertainties, 96, 158, 343, 347
Carbon intensity*, 97
of bioenergy*, 324–325
of electricity, 97, 130
of final energy sectors, 129–130, 130, 137–138, 139
of residual fuel mix, 130
Carbon leakage, 149, 375
Carbon neutrality*, 14, 96
timing of, 12, 96
Carbon price*, 95, 152–153, 153, 375–377
necessity and constraints, 375–377
policies on, 95, 317, 375–377, 460
uniform world carbon price, 375
Carbon sequestration*, 67, 95, 112, 114, 121–124,
147, 266
marine, 17, 121, 125, 178, 227, 228, 229,
3.SM.3.2.8
in peatlands, 221
permanence of, 125
soil carbon sequestration (SCS)*, 17, 121, 219,
268, 269, 270, 345
terrestrial, 112, 121, 125, 146–147, 219, 265, 316
tracking progress toward, 67
See also Blue carbon; Carbon dioxide capture
and storage
Carbon sink. See Carbon sequestration
Carbonate chemistry, 178, 222, 223
Caribbean region, 260, 339–340
small island developing states and territories,
339–340
China
peak car use in Beijing, 376
technology and renewables pathways, 471
Circular economy, 335–336
Cities, 330–334
impacts and risks, 180, 182
sea level rise, impacts, 231–232
transformation* in, 472–474
See also Urban areas; and specific cities
Civil society, 23, 317
Clean Development Mechanism (CDM)*, 474
Climate change commitment*
constant composition commitment, 64
geophysical warming commitment, 64–66, 65
warming commitment from past emissions,
64–66, 65, 1.SM.5
zero emissions commitment, 64–65, 65
Climate education, 22, 317, 456
Climate extreme (extreme weather or climate
event)*, 4, 182
in 1.5°C warmer worlds*, 7
human health and, 240–241
impacts, 7, 177–178, 182, 240
observed changes in, 4, 7, 177, 210, 223, 1.SM.1
precipitation extremes, 7, 178, 189, 190–192, 197
projected changes, 7, 177–178, 189, 190–191, 192
risks from, 11, 181
temperature extremes, 7, 177, 187, 189, 190–191,
192, 210, 255
Climate feedbacks*, 5, 103
biophysical feedbacks, 266–267
Earth system feedbacks, 65, 103–104
land processes and, 268
Climate forcers. See Radiative forcing
Climate models*, 7, 76, 177, 183–184, 274, 3.SM.1.1
Coupled Model Intercomparison Project (CMIP)*,
62, 76
downscaling*, 76, 186, 194
FAIR, 99, 101, 102, 103, 103, 158
HAPPI, 76
integrated multimodel studies, 99
knowledge gaps, 272
MAGICC, 99, 101, 102, 103, 103, 127, 127, 158
reduced-complexity, 2.SM.1.1.1
regional (RCM), 185
Climate monitoring, 317
Climate projections*
climate models and simulations, 76, 183–184
definition of, 184
Climate-resilient development pathways
(CRDPs)*, 22, 52, 73, 448–449, 450–451, 451,
468–472, 475–476
country and community strategies, 470–471
definition, 24, 64
development trajectories and equity, 469–470
FAQ on, 479–480, 480
low-carbon development pathways, 471–472
regional and national factors, 22
sustainable development and, 22, 448–449
trajectories and decision-making in, 451, 480
transformations, equity, and well-being in,
468–469, 472, 472–474
urban transformations* in, 472–473
in Vanuatu, 471
Climate-resilient pathways*, 64
Climate sensitivity*
equilibrium climate sensitivity*, 103, 104
transient climate response*, 96, 184–185
uncertainties, 12
See also Transient climate response to cumulative
CO2 emissions
Climate services*, 337, 338, 385
Climate system*, 5, 208
as a global commons, 353
assessment of changes in, 183, 186
observed changes in, 177
tipping points in, 262–263, 270
Climate target*, 98–99, 151
policy assumptions and, 149
stringent, 112, 126
Climate variability*, 279–281
Coal, 96–97, 132, 132–133, 138, 461
Coastal communities, 9, 181, 182, 222, 453,
Table 3.SM.4
adaptation, 226, 233, 457
adaptation limits*, 455
coastal protection, 225, 226, 227–228,
3.SM.3.2.9
flooding, 11, 181, 231, 235, 249, 252, 252,
3.SM.3.3.3
groundwater, 181
infrastructure risks, 181, 226, 231, 235, 249
livelihoods, 9, 222, 226, 249, 447, 452
relocation of, 457
sea level rise and, 207, 225, 231–234, 243, 249,
252, 457
tourism, 229, 253
Index
Index
605
Coastal ecosystems, 8, 181, 182, 226, 249, 330,
Table 3.SM.4
blue carbon*, 330, 462
framework organisms in, 225–226, 248
integrated coastal zone management, 226
protection services, 227–228, 228, 248
restoration of, 330
saltwater intrusion, 8
sea level rise and, 207, 225, 249
storms/storm surge, 223, 249
stress management in, 330
Co-benefits*, 2, 67, 157, 268, 316, 319, 323
of sustainable development*, 447
Common but Differentiated Responsibilities
and Respective Capabilities (CBDR-RC)*, 318
Community-based adaptation, 315, 330, 360,
384, 458
Conference of the Parties (COP)*
COP 15, 378
COP 16 (Cancun), 353
COP 21, 66, 79, 372
Confidence*, 77, 182
See also Evidence; Likelihood; Uncertainty
Conflict, 245
Conservation agriculture*, 267, 327, 384, 459
Consumption, 53, 56
resource-intensive, 95
responsible, 460
Cook stoves, 460
Cooperation, 23, 461
international, 22, 23, 95, 240
regional, 353–354
Copenhagen Accord, 353
Coral reefs, 8, 11, 179, 229–230, 3.SM.3.2.3,
3.SM.3.2.10, 3.SM.3.3.9
adaptation limits*, 455
bleaching and mortality, 70, 228, 229, 254
Great Barrier Reef (Australia), 228, 251
heat stress, 226, 229
impacts, 221
observed loss of, 8, 228–229
projected losses, 8, 179
projected risks, 53, 225–226, 228, 228–229, 248,
251, 252, 254
protection for coastal areas, 228
storm damage, 222
Cost-benefit analysis*, 76, 150–151
Cost-effectiveness*, 150–151, 152–153, 316
Costs, 76
adaptation, 21–22, 316
economic damages from climate change, 243,
264–265
energy sector transition, 374–375
marginal abatement costs, 16, 95, 150
mitigation, 16, 22, 258, 264, 316
regional economic benefits, 258
social cost of carbon (SCC)*, 150–151, 265, 375
See also Carbon price
Coupled Model Intercomparison Project (CMIP)*,
62, 76
Covenant of Mayors initiative, 354, 355
Crop yields, 9, 11, 145, 145, 147, 179, 236–237, 252,
259, 263, 267, 327, 452, 3.SM.3.3.5
Cuba, risk management in, 339
Cultural practices and resilience, 360
D
Danube River Protection Convention, 356
Decarbonization*
of electricity, 95
of energy sector, 95, 148, 277, 316, 461
of industry sector, 140
of investments, 378
macro-level indicators, 129–130
rate of, 12, 468
transport sector, 333, 461
Decision-making, 321, 360, 365, 456, 462, 469
adaptation, 459
information provision and, 367
participatory, 386, 459
problem-solving, 448–449
sustainable development goals and, 451, 480
Decoupling*, 56, 372, 376, 461
Definitions, 24
See also Glossary
Deforestation*, 263, 264
emissions from, 146
of mangroves, 226, 251
rates of, 146
reducing emissions from (REDD+), 329–330
tipping points*, 263
Deltas and estuaries, 232–233
Demand and supply-side measures*, 97, 111,
161, 317
demand-side measures*, 97, 460–461
investments, 153–154
mitigation and, 97
supply-side measures*, 111
See also Energy supply and demand
Dengue fever, 9, 180, 241
Detection and attribution*, 76, 183, 210–212
attribution methods, 3.SM.1.2
human influences on climate, 4, 51, 59, 81,82,
186–187, 210–212, 282, 1.SM.2, 1.SM.6, 3.SM.2.1
of impacts, 69, 213
regional precipitation on land, 3.SM.2.2.1
regional temperature on land, 3.SM.2.2.1
sea level rise, 252
Developing countries
adaptation finance, 21
development trajectories, 469–470
international cooperation and, 23
Development pathways. See Climate-resilient
development pathways; Pathways
Diet, human, 19, 180, 316, 462, Table 3.SM.12
Direct air carbon dioxide capture and storage
(DACCS)*, 17, 125, 316, 346, 394
Disaster risk management (DRM)*, 10, 316, 336,
338, 385
in Jamaica, 339–340
Disaster*
early warning systems*, 338, 339, 370
preparedness, 339–340
reduction, technological innovations and, 370
Sendai Framework for Disaster
Risk Reduction*, 70
See also Hazard
Discounting*, 152
Disease, 9, 452
dengue fever, 9, 180, 241
diarrhoea, 452
geographic range shifts of vectors, 9, 180, 241
malaria, 9, 180, 241
vector-borne, 9, 180
See also Human health
Displacement*. See Migration
Disruptive innovation*, 22, 111, 319, 323
Double dividend*, 376
Downscaling*, 76, 186, 194, 204
Droughts*, 182, 196–201, 211, 215, 247, 250, 255,
3.SM.3.1.1.2
hotspots, 199, 200, 260
management responses/examples, 356
in Mediterranean Basin and the Middle East,
200–201
observed changes, 196, 211
Palmer Drought Severity Index, 199, 215
precipitation minus evapotranspiration, 198–199,
198, 255
projected, for 1.5°C warming, compared with 2°C,
7, 178, 196–201, 199, 211, 215, 247, 250, 255,
3.SM.3.1.1.2
regional changes, 198–200, 198, 199, 200–201
Drylands, 459
E
Early warning systems (EWS)*, 338, 339, 370
Earth system
feedbacks, 65, 96, 103–104
inertia of, 64
Economic factors, 9, 150–151, 152–155, 264–265
access to finance, 21, 23, 155
circular economy, 335–336, 335
co-benefits (‘double dividend’), 376
depreciation of assets, 375
‘depression economics’, 319
economic damages from climate change, 243,
264–265
green economy, 470–471
incentives, 317, 366, 377
marginal abatement costs, 16, 95, 150, 375
pricing instruments, 317
redistributive policies, 21
regional economic benefits, 258
See also Finance; Investments
Economic growth, 53, 180–181, 182, 319
decoupling from emissions, 56, 372, 376, 461
impacts on, 180–181, 182
mitigation costs and, 258
regional economic benefits, 258
risks at 1.5°C, vs. 2°C, 9, 180–181, 182
in SSPs, 110, 149
Economic indicators/variables
discounting*, 152
Index
Index
606
economic diversification, 21, 71, 448
gross domestic product (GDP)*, 158, 243, 256,
258, 265, 373
gross fixed capital formation (GFCF)*, 317, 373
Economic sectors, 242–244, 256, 3.SM.3.5
energy systems, 243–244
global economic impacts, 256
impacts and risks, 180–181, 242–244, 250, 256
tourism, 242–243
transportation, 244
Ecosystem(s)*, 179, 182, 216–230, 250
adaptation options*, 384, 385, 4.SM.4.3.2
Arctic, 9, 11, 53, 220
coastal, 8, 181, 182, 226, 249, 330
drylands, 459
feasibility of mitigation options, 382
freshwater, 213–216, 221, 247
impacts and risks at 1.5°C, vs. 2°C, 5, 8–9,
11, 179, 182, 250, 453
impacts of temperature overshoot, 277
knowledge gaps, 388
large-scale shifts in, 69
mitigation and, 315, 4.SM.4.2.2
observed impacts, 253
ocean, 8–9, 179, 221–230, 248
resilience, 70
restoration of, 329–330, 459
risks of severe impacts, 53
risks, regional and ecosystem-specific, 219–221
succession in, 69
terrestrial, 8, 11, 179, 216–221, 247, 251,
3.SM.3.3.7
trade-offs, 19
transformations, 8
transitions, 315, 4.SM.4.2.2, 4.SM.4.3.2
Ecosystem-based adaptation, 386, 457–458
Ecosystem restoration, 16, 70, 329–330, 384
Ecosystem services*, 17, 19, 179, 247
carbon sinks, 69, 220, 221
impacts and risks at 1.5°C, vs. 2°C, 8, 9, 179,
247, 256–257
irreversible impacts, 8
marine, 179, 221–230, 248
mitigation and, 315
observed changes, 5
terrestrial, 221
Education (climate education), 22, 317, 385, 456
Effective climate sensitivity. See Climate sensitivity
Effective radiative forcing. See Radiative forcing
El Niño-Southern Oscillation (ENSO)*, 58, 201, 257
deforestation and, 263
La Niña events, 235
response in Guatemala, 356
Electric vehicle (EV)*, 316, 332–333, 333
costs of, 325
Electricity generation/use, 15, 97, 133–134, 135,
138, 243–244, 326
carbon intensity* of, 97
decarbonization, 95
disruptions of, 326
enabling conditions, 387
energy storage, 325–326
evolution of supply over time, 134, 135
investments, 154
from renewables, 15, 96, 134, 324
technological innovations, 370
Electrification, 15, 95, 97, 111, 134, 315, 316, 326
in industry sector, 335, 336
in transport sector, 332–333, 333, 460
Emission pathways*, 12–17, 13, 14–15, 137, 184,
274–276
in a prospective scenario, 276
definition and categories, 24, 59–61, 62
See also Pathways
Emissions
1.5°C pathways*, 6, 12–17, 13, 14–15, 95, 112,
113–118, 113, 117, 463
aggregate, 67–68, 115
anthropogenic, recent trends, 1.SM.7
in archetype pathways, 112–113, 113
benchmark values, 115, 4.SM.1
calculating, 66–68
carbon budget* and, 96
CO2 equivalent emission*, 67, 127
cumulative CO2, 6, 12, 62, 67, 96, 113, 123, 1.SM.6
cumulative CO2 and temperature, 96, 104, 105,
126–127, 127
cumulative emissions*, 6, 12, 62, 67, 123
at current rate, consequences of, 5
decoupling economic growth from, 56, 372, 376, 461
emissions gap, 126, 358
future emissions, commitment to, 66
global, in 2030, 6, 12, 13, 95
long-lived climate forcers, 66–68, 116–118, 117
measuring progress to net-zero emissions, 66–68
Nationally Determined Contributions (NDCs)*,
56, 95, 126–129, 127, 128, 149
negative emissions*, 17, 51, 70, 96, 114, 118
net-zero emissions, 12, 51, 95, 107, 116
net-zero, timing of, 95, 119
non-CO2, 12, 13, 96, 105–107, 115–116, 147, 1.SM.6
past emissions, global warming and, 51, 64–65, 65
peak, 95, 115, 129
peak, timing of, 115, 126–127, 129
reductions, 13, 15, 18, 95, 463
reductions, behaviour change and, 317, 363
reductions, near-term, 17, 96, 124, 126–129, 128
reductions, rate of, 51
reductions, remaining carbon budget and, 96
reductions, technologies and, 369–370
reductions, timing of, 5, 6, 18, 61, 95, 96, 107,
114, 116–118
sectoral pathways, 137
short-lived climate forcers, 64, 66–68, 118, 120, 316
timescales and, 5, 61, 64–66
timing of, 95, 117, 119
warming commitment from past emissions, 64–66,
65, 1.SM.5
zero emissions commitment, 64–65, 65
Enabling conditions*, 18–19, 52, 148–150, 317–318,
338, 352, 386, 474–475, 4.SM.2
adaptation options*, 4.SM.2
enabling behavioural and lifestyle changes,
362–369
enabling technological innovations, 369–372, 370
FAQ, 392–393
international cooperation, 22, 23
knowledge gaps, 390–391
Manizales, Colombia: enabling environment in, 361
for mitigation implementation, 381–383
Energy efficiency*, 15, 96, 137, 140, 315, 316,
460–461
appliances, 316, 331, 460, 461
behavioural responses and, 460–461
building codes, 332, 339, 377
efficiency standards, 377, 378
food production systems, 315–316
improving, 377–378
in industry sector, 315, 335, 335
mitigation options, 460–461
policies, 149, 153, 377–378
sustainable development goals (SDGs) and, 448
Energy sector, 15, 129–144, 243–244, 315, 324–327
adaptation options*, 384, 385
carbon dioxide capture and storage in, 326–327
carbon intensity, 129–130, 130, 137–138, 138, 139
decarbonization, 95, 148, 277, 316, 461
decarbonization, macro-level indicators, 129–130
diversification of, 21, 448
electrification, 15, 95, 97, 111, 134, 315, 316, 326
emissions, 96, 137, 138
end-use sectors, 136–144
energy security, 387
feasibility of mitigation options, 382
final energy, 137, 138
fuel switch, 460–461
hybrid systems, 326
infrastructure, 326, 384, 385
investments, 16, 22, 95–96, 153, 155, 372, 373–374
knowledge gaps, 388
low-carbon pathways, 462, 464–466
low-carbon technologies, 15, 16, 96
mitigation options, 12, 14, 460–461, 4.SM.4.2.1
renewable energy, 14, 15, 96, 111, 131, 132–133,
316, 324
solar energy, 96
synergies with Sustainable Development Goals, 19
transformation, 129–144, 316, 463
transitions in 1.5°C pathways*, 15, 96–97, 130,
315, 316, 324–327, 374–375, 4.SM.4.2.1,
4.SM.4.3.1
transitions, speed and scale of, 320, 320
water and, 326, 384, 464–466
water-energy-food (WEF) nexus, 386–387
Energy supply and demand, 15, 17, 96–97,
129–136, 316, 460–461, 466
in 1.5°C warmer worlds, 161, 162, 316
access to energy, 464
air conditioning, 243
batteries, 325
bioenergy*, 12, 17, 96, 111–112, 124, 324–325
carbon intensity of, 129–130, 130, 461
demand reductions, 95, 137
disruptions and vulnerabilities, 326
emissions pathways, 12, 14, 15, 95
energy storage, 316, 325–326
Index
Index
607
evolution of primary energy contributions, 130–132,
131, 132–134
final energy demand, 137, 138
fossil fuels, 96–97
grid flexibility resources (GFR), 325
low-demand scenarios, 110, 111, 448
mitigation options, 460–461
primary energy supply, 96–97, 130–132, 131,
132–133
smart grids, 316
in SSPs, 109–110, 110
sustainable development goals
(SDGs) and, 447–448
synergies and trade-offs, 19, 20–21, 448
transformations in, 129–136, 130–135
urban, 331
See also Electricity generation/use
Enhanced weathering*, 17, 112, 268, 269, 270,
345–346, 462–463
costs, 316, 345
side effects, 345–346
Equality*, 448–449, 451–453
in 1.5°C warmer worlds*, 451–453
inequality, 456
inequality, reducing, 18–23, 445–538
Equilibrium climate sensitivity.
See Climate sensitivity
Equity*, 18, 23, 51, 54–55, 448–449, 456, 469–470,
479
in 1.5°C warmer worlds*, 451–453
burden sharing*, 380, 470
climate-resilient development
pathways*, 22, 448–449, 469–470
conditions for achieving, 474–475
disproportionate impacts and, 51
fairness* and, 449, 469, 479
gender equity*, 23
intergenerational equity*, 55
international equity, 55
justice and, 22, 55, 456, 470
mitigation efforts and, 18, 55
national equity, 55, 470
policies and, 22, 456
procedural equity*, 55, 73
research gaps, 475–476
responsibility–capacity–need assessment, 470
in social-ecological systems*, 338–341
trade-offs, 19
Ethics*, 51, 52
European Union, Covenant of Mayors, 354, 355
Evidence*, 451
Exposure*
factors influencing, 53
numbers of people exposed, 178, 246, 453
See also Hazard; Risk; Vulnerability
Extinction, 8, 179, 218, 256–257
commitment to, 218
Extratropical cyclone*, 203–204, 211
See also Tropical cyclone
Extreme weather events*, 182, 255
floods and droughts, 214–215, 255
frequency of, 223
heavy precipitation, 255
See also Climate extreme
Extremes. See Climate extreme; and specific topics,
e.g., precipitation
F
Fairness*, 449, 469, 479
nation-level fair shares, 470
FAQs. See Frequently Asked Questions
Farmer managed natural regeneration (FMNR), 459
Feasibility*, 18–19, 52, 56, 71–72, 380–386, 381,
392–393, 393
adaptation options*, 381, 384–386, 385,
4.SM.4.3.1-4.SM.4.3.5
assessment of, 71–72, 380, 381, 382–383, 4.SM.4.1
definition, 52
dimensions of, 71–72, 380, 381, 392
enabling conditions*, 18–19, 52, 56
mitigation options*, 381, 381, 382–383,
4.SM.4.2.1-4.SM.4.2.5
Feedback. See Climate feedbacks
Fiji, freshwater resources, 368
Finance, 21–22, 23, 148–149, 317, 361–362, 372–380,
474
access to, 21, 23, 155, 317, 456
adaptation financing, 21–22, 379, 456
challenges of, 372–375, 373–374, 379
climate-friendly products, 378
de-risking, 317, 378–379
global and national systems for, 317–318, 380
Green Climate Fund, 74, 379
green instruments, 378, 474
innovative, 315, 380
knowledge gaps, 391
low-emission assets, 317
mobilization of, 19, 456
multilateral and national development banks, 317
new forms of, 374, 380, 474
policy instruments and, 317, 372–380
private sector, 21, 22
public-private partnerships, 317, 474
public sector, 21, 317
redirection of, 317, 374, 378
See also Investments
Financial institutions*, 361–362
Fires, 244, 259
forest fires, 8, 247
tundra, 262
Fisheries, 8, 9, 11, 237–238, 248, 452
adaptation measures, 238
fin fish, 180, 226–227, 237–238, 3.SM.3.2.7,
3.SM.3.3.10, 3.SM.3.2.12, 3.SM.3.2.13
foodwebs and, 226–227, 248
hypoxia and, 224
livelihoods, 452
management, 227
productivity change, 225, 249, 258
projected impacts, 8, 9, 11, 178, 222, 228, 248, 257
range shifts, 222, 248
restoration of, 330
risks, 180, 228, 237–238, 251, 252, 257
Floods*, 11, 182, 201–203, 211, 214–215,
3.SM.3.1.1.2
coastal, 181, 231, 235, 249, 252, 252, 3.SM.3.3.3
damage from, 214, 215
Danube River Protection Convention, 356
fluvial, 201–203, 214, 247, 251–252, 252,
3.SM.3.3.4
management in Rotterdam, The Netherlands, 342
numbers of people at risk, 452
observed changes, 201, 211
Philippines, flood measures, 368
projected changes, 179, 201–203, 202, 211, 214,
3.SM.3.1.1.2
risks, with 1.5°C warming, compared with 2°C, 7,
178, 179, 181, 201–203, 202, 214–215, 247,
251–252, 252
sea level rise and, 8
Fluorinated gases, 118, 120
Food, Table 3.SM.12
GHG-intensive foods, 97, 147
healthy diets and choices, 19, 97, 147, 180, 462
land use for, 97, 145
plant-based proteins, 112
prices, 447, 462, 464
quality/nutrition, 327, Table 3.SM.12
water-energy-food (WEF) nexus, 386–387
Food demand
reducing, 464, 466
in SSPs, 110, 110, 111
Food production systems, 178, 236–240, 250, 252,
327–329, 453, 464, Table 3.SM.5
climate-smart food production, 239
efficiency of, 315–316, 464
genome modification, 329
land use and, 327–329
mixed crop-livestock production, 315, 328
projected impacts, 179–180, 236–240, 250
technological innovations, 316, 329
tipping points*, 263, 264
See also Agriculture; Crop yields
Food security*, 180, 182, 237, 238–240, 250
decline in, 53
enhancing, 315–316
food insecurity, 447
mitigation pathways and, 464
projected impacts, 179–180, 239, 250, Table 3.SM.5
risks to, 238–239
strategies for improving, 239–240
Food shortages, 9
Food wastage*, 316, 328–329, 462
Forcing. See Radiative forcing
Forest fires, 8, 247
Forests*, 220, 316, 329–330
agroforestry, 328, 384
Amazon tropical forest, 221, 263, 340
Australian rainforest, 254
boreal, 8, 263, 264
as carbon sinks, 340
CDR options and, 316
ecosystem restoration, 329–330
emissions, 14
impacts, 220
Index
Index
608
land area for, 16, 97
land-use change, 146
rainforests, 254, 263, 264
REDD+, 329–330
responsible sourcing of products, 462
risks, 8, 220–221
tipping points*, 263, 264
See also Afforestation; Deforestation; Reforestation
Fossil fuels*
in 1.5°C pathways*, 14–15, 15, 96–97
combined with CCS, 97, 135
countries/economies dependent on, 448,
461, 462
energy sector use, 15, 96–97, 131, 131,
132–133, 138
greenhouse gas emissions, 53, 114
market preference, shifting, 317
reducing investments in, 378
Framing and context, 49–92
assessment and methodologies, 75–76
confidence, uncertainty and risk, 77
feasibility, 71–72
framing asymmetries, 55
global response, 70–75
impacts, 69–70
knowledge base, 53–56, 75–76
sustainable development, 73–75
transformation and transitions, 73
understanding 1.5°C, 56–64
Frequently Asked Questions (FAQs)
How Close are we to 1.5°C?, 81, 82
What are Carbon Dioxide Removal and Negative
Emissions?, 394, 395
What are the Connections between Sustainable
Development and Limiting Global Warming to
1.5°C above Pre-Industrial Levels?,
477–478, 478
What are the Impacts of 1.5°C and 2°C of
Warming?, 282–283, 283
What are the Pathways to Achieving Poverty
Reduction and Reducing Inequalities while
Reaching a 1.5°C World?, 479–480, 480
What do Energy Supply and Demand have to
do with Limiting Warming to 1.5°C?, 161, 162
What Kind of Pathways Limit Warming to 1.5°C
and are we on Track?, 159, 160
What Transitions Could Enable Limiting Global
Warming to 1.5°C?, 392–393, 393
Why are we Talking about 1.5°C?, 78, 80
Why is Adaptation Important in a 1.5°C-Warmer
World?, 396–397, 397
Freshwater systems, 182, 213–216, 221, 247
adaptation initiatives, 368
extreme events, 214–215
freshwater stress, 181
knowledge gaps, 272
water temperature, 214
See also Water resources
Fuel switch, 460–461, 481–506
Fybnos and succulent Karoo biomes, 260, 261
G
Gender equity*, 23, 452
General circulation model (GCM). See Climate models
Genome modification techniques, 329
Geophysical relationships, 101–107
climate and Earth-system feedbacks, 103–104
geophysical uncertainties, 96, 101–104
knowledge gaps, 157–158
non-CO2 climate forcers, 101–103, 103
Geophysical warming commitment, 64–66, 65
Glaciers*, 206
Global climate model (GCM). See Climate models
Global financial systems, 317–318
Globalisation, 319
Global mean surface temperature (GMST)*,
56–57, 57, 177, 186, 274
1.5°C rise, factors in, 4, 274
anomalies*, 183, 210
definition, 24
measurement of, 12
observed, 4, 6, 186
past emissions and, 51
Global mean surface air temperature (GSAT)*,
12, 56
Global response, strengthening, 18–23, 70–75,
313–443
1.5°C-consistent pathways, implications of,
320–321, 320, 448
accelerating the response, 319–320
adaptation options, 321, 336–337, 338
change, far-reaching and rapid, 352–380, 392
change, historical rates of, 322
cooperation, 22, 23
enabling change, 21–22, 315–318
feasibility assessments, 380–386, 381, 382–383,
385
finance and investments, 317, 321, 361–362,
372–380
governance and policies, 23, 71, 315, 316, 317,
321, 352–355
implementation, 23, 70, 71, 315, 317, 319,
320–323, 352–380
implementing adaptation, 383–386, 385
implementing mitigation, 381–383
integration and enabling transformation, 380–387
knowledge gaps, 318, 387, 388–391
levels of ambition, raising, 315
monitoring and evaluation (M&E)*, 386
policy instruments and finance, 372–380
response options, 19–21, 70–71, 316–317
sustainable development and, 18, 22, 316, 321
synergies and trade-offs, 316, 386–387
system transitions, and rates of change, 322–323
systemic changes, 323–349
transformation and transitions, 70, 73, 315,
380–387
transitions, speed and scale of, 317, 320, 320
Global Temperature-change Potential (GTP),
66–68
Global warming*, 4–6
commitment to continued warming, 64–66, 65,
1.SM.5
current level of, 4, 51, 53, 76, 106, 177, 1.SM.1
definition, 24, 51, 56
with emissions continuing at present rate, 4
geophysical warming commitment, 64–66, 65
human experience of present-day, 53, 1.SM.1
human-induced, 4–5, 51, 53, 53, 54, 59, 81, 82,
186–187, 282, 1.SM.2, 1.SM.6
level in 2017, 51, 59, 81
maximum temperature reached, 5
observed, 4, 51, 53, 53, 58–59, 189–190,
1.SM.1, 1.SM.2, 1.SM.3, 1.SM.6
past emissions and, 51, 64–65, 65, 72
peak in, 5, 65, 96, 101, 177, 277, 278
pre-industrial* reference period,
51, 56, 57–59, 184
projections, 4, 81, 82, 95, 187–188, 188
reference periods, 56–59, 184
regional/seasonal variations in, 4, 59, 60, 81
temperatures used for definition, 51, 106
timescales and persistence, 5
total warming, 59, 61
See also Global mean surface temperature;
Temperature
Global warming of 1.5°C, 4–6, 56–64, 187, 274
1.5°C pathways*, 12–17, 51, 93–174
already experienced in some regions
and seasons, 4, 51, 59, 68, 81, 452
closeness to (FAQ), 81, 82
context of sustainable development
and poverty eradication, 18–23
framing and context, 4–6, 49–92
future emissions and, 6, 13
impacts and risks, compared with 2°C,
5, 7–10, 11, 51, 175–311, 261
not considered ‘safe’, 447, 455
projected climatic changes, 7–10, 186–188
projected timeline for reaching,
4, 95–96, Table 3.SM.7
Reasons for concern (RFCs)*, 10, 11, 181
reference period, 56–59, 184
returning to, after overshoot, 5, 17, 61, 96
stabilization responses/scenarios, 147, 158, 182,
184–185
strengthening the global response, 18–23, 70–75,
313–443
synergies and trade-offs, 19
temperature range for, 51, 187, 188, 275
See also 1.5°C warmer worlds*
Global warming of 2°C, 100
emissions and, 116
impacts and risks, compared with 1.5°C, 5, 7–10,
11, 175–311, 261
OECD scenario for, 373
Reasons for concern (RFCs)*, 10, 11
regions with high risks, 247–250
runoff and floods, 178, 211
Global warming of 3°C, 18, 261
rainforests and, 263
Global Warming Potentials (GWPs), 66–68
Governance*, 19, 71, 316, 317, 352–355
adaptive governance*, 315
Index
Index
609
challenges in 1.5°C pathways, 95
Covenant of Mayors initiative, 354, 355
governance capacity*, 71
governance framework, 317, 359
inclusive, 475
international, 352–354, 474
knowledge gaps, 390
linkages across sectors, 71
local and regional, 316, 354, 355
multilevel governance*, 19, 23, 317, 352–355,
355, 356, 384, 386, 474–475
national, 316, 353, 361
partnerships among actors, 23
sub-national, 354
water-energy-food (WEF) nexus, 386–387
See also Policies
Green bonds, 378
Green Climate Fund, 74, 379
Green economy, 470–471
Green infrastructure*, 10, 316, 334, 334, 384, 385
investment in, 316
Greenhouse gas(es) (GHGs)*,
long-lived, 64–66, 66–68, 116–118
short-lived, 64, 66–68, 316
See also Carbon dioxide; Methane; Nitrous oxide;
Ozone
Greenhouse gas emissions, 14–15, 18
aggregate, 115
benchmark values, 115
cumulative emissions*, 6, 12, 62
drivers of, 53
global, in 2030, 12, 13
reductions in, 6, 12, 13, 14–15, 95
reporting of, 66
timing of reductions, 6, 13, 95
See also Emissions
Greenhouse gas removal*. See Carbon dioxide
removal (CDR)
Greenland ice sheet, 7, 178, 206, 208–209, 257,
271, 282
Gross domestic product (GDP)*, 158, 243, 256,
258, 265, 373
Gross fixed capital formation (GFCF)*, 317, 373
Gross world product (GWP), 256
Groundwater, 15, 3.SM.3.1.1.3
coastal, 181
Guatemala
Indigenous Table for Climate Change, 360
Maya watershed meteorological forecasts, 360
response to drought and El-Niño, 356
Gulf Cooperative Council (GCC) countries, 462
H
Happiness index (Bhutan), 387
Hazard*, 68, 186–212, 210–212
collocated and/or concomitant, 188
See also Disaster; Risk; Vulnerability
Health. See Human health
Heat-related morbidity and mortality, 9, 11,
180, 240–241, 250, 252, 252, 263, 264, 3.SM.3.3.1
Heat stress, 452
coral reefs, 226, 229
Heatwaves*, 9, 263, 264
in cities, 242
deadly, 263, 264
extreme, 177
marine, 177
numbers of people exposed, 178
observed changes, 177
projected changes, 177–178
tipping points*, 263, 264
Holocene*, 53
Holocene Thermal Maximum (HTM), 208
Hotspots, 182, 258–260, 261
drought*, 199, 200
precipitation, 193, 194
temperature, 190–191, 193
Human behaviour*, 362–369
adaptation behaviour*, 363
adaptation options*, 457
behavioural change*, 19, 21, 22, 97, 315, 317, 461
behavioural change, enabling, 362–369
behavioural change, knowledge gaps, 390–391
dietary choices, 19, 97, 147, 180, 316, 462
energy efficiency* and, 460–461
factors affecting, 364–365
habits, heuristics, and biases, 365, 461
knowledge and, 364
mitigation behaviour*, 362, 363
motivation and, 364–365
rebound effect, 460
See also Values
Human health, 9, 178, 182, 240–241, 250, 385
adaptation limits*, 455
air quality and, 241, 250, 464, Table 3.SM.9
benefits of emissions reductions, 12
co-benefits, 157
cold-related mortality, 241
heat-related morbidity and mortality, 9, 11, 180,
240–241, 250, 252, 252, 263, 264, 3.SM.3.3.1
impacts and risks at 1.5°C, vs. 2°C, 9, 180, 182,
240–241, 250, 252, 453
occupational health, 241, 250
population health, 337, 338, 385, 457
risks, 180, 240–241, 252
temperature-related risks, Table 3.SM.8
tipping points*, 263, 264
trade-offs, 19
urban areas, 180
vector-borne diseases, 9, 180, 241, Table 3.SM.10
Human-induced warming, 4, 51, 59, 81, 82,
186–187, 188, 282, 1.SM.2, 1.SM.6
equal to observed warming, 51, 59
rate of, 66
Human population, 51, 319
current, 319
displacement/migrations of, 180, 181, 244–245,
337, 338, 385
growth of, 95, 319
in regions where 1.5°C already exceeded, 51
in SSPs, 109, 110
Human rights*, 55, 450, 460, 469–470, 475
Human security*, 9
Hydrofluorocarbons (HFCs), 12, 96, 118, 341–342,
342
radiative forcing from, 342
Hydrogen, 15, 315, 335, 336
Hydrological cycle*, 191–196
Hydropower, 201, 214, 243, 466
I
Ice sheets*
albedo and, 257
Antarctic ice sheet, 7, 178, 208–209, 257, 258,
271, 282
Greenland ice sheet, 7, 178, 206, 208–209, 257,
271, 282
marine ice sheet instability (MISI), 257, 258
sea level rise and, 7, 178, 206, 208, 257, 271
thresholds, 257
time frame for loss of, 257
tipping points, 282
(Climate change) Impact assessment*, 76, 185–186
Impacts*, 7–10, 68–70, 175–311
in 1.5°C and 2°C warmer worlds*, 7–10,
177–179, 182, 319
in 1.5°C pathways, vs. overshoot pathways, 51,
61, 62
attribution for, 69, 213
avoided, 18, 68, 183, 253–265, 447, 452–453,
453, 475
climate extremes and, 7, 177–178, 182
coastal and low-lying areas, 231–234, Table 3.SM.4
definitions, 24, 68
direct vs. indirect, 69
disproportionate, 11, 51, 447, 452
distribution of, 10, 11, 18, 181, 255–256
drivers of, 69
economic sectors and services, 180–181, 182,
242–244, 250, 256
ecosystems, 178, 179, 182
emission pathways* and, 51, 282
FAQ on, 282–283, 283
food systems, 179–180, 182, 236–240, 250,
Table 3.SM.5
global aggregate, 10, 11, 181, 182, 256–257
global and regional climate changes, 186–212,
210–212
human health, 9, 180, 182, 240–241, 250,
252, 453
impact assessment*, 76, 185–186
impact cascades, 69, 245, 452
irreversible, 5, 61, 177, 251, 252, 254
knowledge gaps, 272–273
land use, 179–180
livelihoods, poverty, and migration, 244–245, 447
marine ecosystems, 8–9, 179, 221–230
non-linearity, 69–70
observed, 5, 53, 212–253
ocean, 5, 8–9, 178, 179, 180, 182, 221–230, 228,
248–249, 3.SM.3.2.1-3.SM.3.2.13
projected risks, 7–10, 212–253
regional, 9, 68, 180–181, 182, 189–196
sea level rise, 7–8, 181, 182, 206–207, 212
Index
Index
610
small islands and coastal areas, 181, 182
summary of, 182–183, 182, 247–250, 251–253
terrestrial ecosystems, 8, 11, 179, 216–221, 252,
Table 3.SM.2
time-integrated, 61, 62
timescales of, 61, 62
uncertainties*, 69
uncertainty propagation, 3.SM.1.3
urban areas, 241–242
water resources, 179, 3.SM.3.1.1.2-3.SM.3.1.1.4
Implementation. See Global response, strengthening
Inclusion/inclusive processes, 331, 333, 353, 381,
449, 475
cultural considerations, 384
decision-making, 456
Incremental adaptation. See Adaptation
India, technology and renewables pathways, 471
Indigenous knowledge*, 22, 315, 337, 338, 339,
385, 456, 480
community adaptation and, 360
in Guatemala, 360
Indigenous Table for Climate Change (Guatemala),
360
in Pacific Islands and small island developing
states, 360
in Tanzania, 360
Indigenous peoples, 23, 447
in Arctic, 9, 339
cultural beliefs, 364
land tenure, 462
Maya (in Guatemala), 360
risks and impacts, 9
Industry sector, 334–336, 4.SM.4.3.4
adaptation options*, 385, 386
bio-based feedstocks, 335–336, 335
carbon capture and storage (CCS), 335, 336
changes in structure of, 375
decarbonization, 140
electrification and hydrogen, 335, 336, 460
emissions, 15, 114, 140, 334
energy efficiency, 315, 335, 335, 460
energy-intensive industry, 334
feasibility of mitigation options, 383
final energy demand and use, 138–140, 139
knowledge gaps, 389
mitigation options*, 335, 4.SM.4.2.4
substitution and circularity, 335, 335, 460
technological innovations, 370, 460
transitions in, 15, 334–336, 460, 4.SM.4.3.4
transitions, speed and scale of, 320, 320
Inequality
in 1.5°C warmer world*, 447
adaptation pathways* and, 458–459
increased, 53, 319
persistent, 471
reducing, 18–23, 72, 445–538, 456, 475
research gaps, 475–476
See also Equality
Information and communication technology
(ICT)*, 316, 319
Information flow and sharing, 377–378, 456, 457
Infrastructure
adaptation options*, 384–386, 385, 4.SM.4.3.3
climate-resilient, 386
coastal, 181, 226, 231, 235, 249
decommissioning of existing, 374
feasibility of mitigation options, 382
floods and, 181
green infrastructure*, 10, 316, 334, 334, 384, 385
investments in, 21, 333, 373–374, 374
knowledge gaps, 388–389
lock-in of carbon-emitting, 18, 126
low-emission, 317, 374
mitigation options*, 4.SM.4.2.3
sea level rise and, 8, 231, 249
transitions in, 15–16, 4.SM.4.3.3
urban, 331, 333
Insects, 254–255
phenology, 216, 218
pollination by, 216, 218, 255
range loss, 254–255, 256–257
species loss, 179, 218
Institutional capacity*, 19, 71, 359–362
cooperative institutions and social safety nets, 362
enhancing, 359–362, 384
monitoring, reporting, and review, 361
policy design and implementation, 359–360
Institutions*, 359–362, 474–475
financial, 361–362
institutional capacities, 359–362
knowledge gaps, 390
monitoring, reporting, and review, 361
reform: Manizales, Colombia, 361
Integrated assessment*, 95
Integrated assessment models (IAMs)*, 99,
100–101, 108–109, 136–137
assumptions, 2.SM.1.2.2, 2.SM.1.2.3
bioenergy and BECCS deployment in, 124, 268
CDR and, 268–269
global economic impacts, 256
knowledge gaps, 158
land use and bioenergy modelling, 2.SM.1.2.4
multiple IAMs, 463–464
scope, use and limitations, 2.SM.1.2.1
Integrated assessment model (IAM) scenario
database
configuration, 2.SM.1.3.1
data collected, 2.SM.1.3.4
modelling Framework Reference Cards, 2.SM.2
Part 2
overview of mitigation measures, 2.SM.1.2.6
overview of scenarios, 2.SM.1.3.2
overview of studies, 2.SM.1.3.3
scenario classification, 2.SM.1.4
summary of models, Table 2.SM.7
Interconnectivity, 52, 54, 319
International agreements, 70, 317
International cooperation, 22, 23, 95
Mekong River Commission, 240
International governance, 352–354, 474
Internet of Things (IoT)*, 331
Invasive species, 8, 9, 223
Investments, 21, 95–96, 149, 153–155, 316,
372–380
decarbonization*, 378
energy-related, 16, 95–96, 153, 155
green investment, 474
incentives, 317
investment needs, 373–374
knowledge gaps, 158
low-emission, 154, 317, 378
mitigation, 21, 95–96, 466
policy instruments and, 317
speed and scale of change, 321
upscaling of, 15, 317
world investment, 317, 373
See also Finance
IPCC Fifth Assessment Report (AR5), 51, 81
IPCC Special Report on 1.5°C (SR1.5), 4, 74, 79
storyline, 77–78, 78
timeline of, 80
Iron fertilization. See Ocean fertilization
Irreversibility*, 5, 61, 177, 251, 252, 254, 262, 277
temperature overshoot and, 8, 61, 179
See also Tipping points
Italy, Province of Foggia, multilevel governance
in, 355
J
Jamaica, 339–340
Justice*, 448–449, 456, 469
distributive justice*, 55
justice-centered pathways, 470
procedural justice*, 55
social justice*, 22, 448–449
See also Equity; Ethics; Fairness; Human rights
K
Kampala, Uganda, Climate Change Action
Strategy, 340
Kigali Amendment, 118
Kiribati, adaptation in, 368, 471
Knowledge gaps, 157–158, 388–391
impacts and risks, 272–273
See also specific topics
Knowledge sources, 52, 53–56, 75–76
grey literature, 76, 451
indigenous knowledge*, 22, 315, 337, 338, 339,
385, 456, 480
local knowledge*, 22, 339, 457
scientific literature, 75, 451
Krill, 227, 228, 3.SM.3.2.6
Kyoto Protocol*, 80, 353
Kyoto GHG-emissions, 14, 115–116, 117, 119, 126
L
Land management, 17, 19, 180
carbon dioxide removal and, 121, 180
Land surface air temperature*, 56
Land use*, 144–148, 180, 327–329
adaptation options*, 384, 385, 4.SM.4.3.2
Index
Index
611
for agriculture and food, 16, 97, 112, 146, 327–329
carbon dioxide removal (CDR)* and, 125, 126,
265–266, 268–270, 343
climate-resilient, 333
feasibility of mitigation options, 382
governance and, 17
intensification of, 16
knowledge gaps, 388
mitigation options, 148, 265–266, 382, 462–463,
4.SM.4.2.2
mitigation potential, 315
modelling, 2.SM.1.2.4
planning: Manizales, Columbia example, 361
risks of carbon release, 221
sustainability of, 16, 97
synergies and trade-offs, 19, 20–21
transitions in, 16, 17, 96, 97, 144–148, 315,
327–329, 4.SM.4.3.2
urban, 316, 333
Land-use change (LUC)*, 112, 126, 144–148,
179, 180
in agricultural sector, 98, 144–148
bioenergy production and, 69
biophysical feedbacks, 266–267
CDR and, 268–269
overview of, 145
pace of, 145, 146
risks in mitigation pathways, 69, 97, 265–266
in SSPs, 145
Large scale singular events, 10, 11, 181, 254,
257–258
Last Glacial Maximum (LGM), 208
Lifestyles, 315
choices, 97, 180
consumption and, 53, 56, 95, 97
emissions reduction through, 317
lifestyle change, enabling, 362–369
lifestyle change, knowledge gaps, 390–391
low energy demand, 97
low resource use, 97
mitigation and adaptation behaviour, 362–363
in SSPs, 110
sustainable, 276
See also Food; Human behaviour
Likelihood*, 77, 182
Limpopo Watercourse Commission, 356
Livelihoods*, 73, 182, 244
agricultural, 55, 315, 447
coastal, 9, 222, 226, 249, 447, 452, 455
impacts and risks of 1.5°C warmer worlds*, 452
poverty and, 244
security, promoting, 456–457
Livestock, 9, 180, 264, 327–328
animal feed, 112
emissions, 147, 327
land use, 97
mixed crop-livestock production, 315, 328
production, 237
in the tropics and subtropics, 263, 264
Local communities, 23
Local knowledge*, 22, 339, 457
Local participation, 456
Lock-in*, 18, 126, 129
London, U.K.
adaptation and disaster risk management, 458
car use/policies, 366
Long-lived climate forcers (LLCF)*, 66–68,
116–118, 117
time scales, 64–66
Loss and Damage*, 454–456
Low-carbon pathways, 471–472
M
Maharashtra, India, water resources, 368
Maladaptive actions (Maladaptation)*, 19,
386, 396
Malaria, 9, 180, 241, 452
Mangroves, 225, 226, 228, 228, 248, 252, 462,
3.SM.3.2.1, 3.SM.3.3.8
replanting, 330, 457
Manizales, Colombia, 361
Marginal abatement costs, 16, 95, 150, 375
Marine ecosystems. See Ocean ecosystems
Mayan K’iché population in Guatemala, 360
Mediterranean region, 259, 261
droughts, 200–201
threatened systems, 254
Mekong River basin, 239–240
Methane (CH4)*, 268, 316, 341, 342
AFOLU sector, 118, 147, 147
agricultural, 96
emissions, 13, 118, 120
emissions, evolution of, 96
emissions reduction, 12, 95, 102, 157, 268, 316
mitigation potential, 118
release from permafrost*, 12, 104
release from wetlands, 12
zero emissions commitment (ZEC), 65
Migration*, 180, 181, 232, 244–245, 337, 338, 385
as adaptation, 457
(internal) displacement*, 245
sea level change* and, 232
Millennium Development Goals (MDGs)*, 74,
450, 477
Mitigation*, 19–21, 70, 93–174
in 1.5°C pathways*, 12–17, 51–52, 93–174, 465
adaptation and, 19, 386–387, 4.SM.4.5.1
classification of, 99–100, 100
costs, 16, 22, 258, 264, 316
decisions after 2030, 56
definition, 70
demand-side measures*, 97
equity considerations, 55
feasibility, 15, 380, 381
global response, strengthening, 19–21, 70–75,
313–443
implementing, 381–383
integrated mitigation studies, 95
investments, 21, 95–96, 466
knowledge gaps, 388–391
non-CO2 mitigation, 95, 96, 105–106, 108,
115–116, 120, 265, 268
risks and risk reduction, 5, 179, 448
socio-economic challenges to, 110
sustainable development and, 12, 19–21, 97,
156–157, 447–448, 459–466, 465, 481–509
synergies and trade-offs, 18–21, 20–21, 72, 97,
157, 316, 386–387, 391, 459–463, 465,
4.SM.4.5.1
synergies with adaptation, 386–387, 475,
4.SM.4.5.1, 4.SM.5.2
time frames for, 277, 278, 279–281
See also 1.5°C pathways; Pathways
Mitigation behaviour. See Human behaviour
Mitigation options*, 19–21, 316–317, 319, 323,
324–347, 463, 481–509
1.5°C pathways*, 100, 110–112, 316–317, 465
CDR, 4.SM.4.2.5
emissions reduction with, 12, 13, 14–15
enabling conditions, 381–383
energy supply and demand, 460–462, 4.SM.4.2.1
feasibility assessment, 381, 381, 382–383,
4.SM.4.2.1-4.SM.4.2.5
industrial system, 4.SM.4.2.4
land-based, 16, 462–463, 4.SM.4.2.2
mitigation–SDG table, 481–509
overview, 2.SM.1.2.6
SDGs and, 19–21, 20–21, 448
synergies and trade-offs, 459–463, 463, 465,
4.SM.4.5.1
urban and infrastructure, 4.SM.4.2.3
Mitigation pathways*, 93–174, 265–271
1.5°C pathways*, 12–17, 13, 14–15, 60–61, 98,
101, 102, 108–129, 110, 2.SM.1.5
2°C pathways, 96, 100, 101, 102
adaptive mitigation pathway, 60–61
carbon dioxide removal (CDR) in, 118–125, 180
challenges, opportunities, and
co-impacts, 147–157
emissions and, 12, 14–15
four model pathways, 12, 14–15, 61, 62
geophysical characteristics, 101–104
groups/classification, 61, 62, 113–114, 113
land-use change, 265–266
overview, 108–129, 129
prospective, 60, 63
scenarios in, 98–100, 100, 277, 279–281
sustainable development and, 463–472, 465,
2.SM.1.5
synergies and trade-offs, 465
transformations, 129–157, 466
See also 1.5°C pathways; Pathways
Mitigation potential, 118, 315, 363
Mitigation scenarios*. See Mitigation pathways
Models. See Climate models; Integrated assessment
models (IAMs)
Monitoring and evaluation (M&E)*, 386
Monitoring, reporting, and review institutions,
361
Monsoon, 194, 262–263, 264
Montreal Protocol, 118, 353
Mosquitoes, 241
Motivation*, 364–365
Mountain ecosystems, 254
Index
Index
612
N
Narratives*, 52, 109
Nationally Determined Contributions (NDCs)*,
56, 95, 126–129, 127, 128, 149, 159, 357–359
adaptation and, 359
consistency of, 357–359
remaining carbon budget and, 113–114
uncertainties and, 358
Natural gas, 97
NDCs. See Nationally Determined Contributions
(NDCs)
Negative emissions*, 17, 51, 70, 118–121, 394, 395
474
CDR, role in, 70, 114, 118
FAQ on, 394, 395
See also Net-zero emissions;
Net-zero CO2 emissions
Net negative emissions*, 51, 96, 114, 116, 474
Net-zero emissions*, 5, 24
Net-zero CO2 emissions*, 12, 51, 95, 116
definition, 24
measuring progress to, 66–68
necessary to stabilize GMST, 116, 161
timing of, 5, 12, 13, 61, 95, 107, 116, 119
New York, United States, adaptation initiatives, 340
Nitrogen fertilizer, 116
Nitrous oxide (N2O)*, 13, 66
agricultural, 96, 116–118, 147
bioenergy and, 12
emission increases, 96
emission reductions, 116–1118
Non-CO2 climate forcers, 96, 120, 341–342
geographical variation in, 103
reductions in, 95
uncertainties, 101–103, 103, 106, 108
Non-CO2 emissions*, 12, 13, 96, 106, 115–116,
265, 1.SM.6
agricultural, 147, 147
reducing, 341
remaining carbon budget* and, 105–107, 108
Non-governmental organizations, 22
Non-overshoot pathways. See Overshoot; Pathways
Nuclear energy, 14, 15, 325, 461
costs of, 325
role in primary energy supply, 130–131, 132,
132–133
safety of, 325
water use and, 466
O
Ocean(s), 8–9, 178, 182, 221–230, 248–249,
3.SM.3.2, Table 3.SM.3
adaptation options, 225
biodiversity, 8
carbon sequestration, 17, 121, 178, 222, 227, 228,
248, 257–258
carbon uptake, 17, 121, 178, 227, 228, 229,
3.SM.3.2.8
circulation, 204–205, 212, 223, 248
foodwebs, 226–227, 228, 248
heatwaves*, 177
hypoxia and dead zones, 179, 210, 224, 248
impacts and risks at 1.5°C, vs. 2°C, 5, 8–9, 178,
179, 180, 182, 221–230, 228, 248–249,
3.SM.3.2.1-3.SM.3.2.13
irreversible impacts, 8
knowledge gaps, 272–273
productivity/fisheries, 8, 179, 249
projected changes, 8–9
pteropods, 224, 226–227, 3.SM.3.2.4
Reasons for Concern, 3.SM.3., Table 3.SM.6
salinity, 209
Southern Ocean, 257–258
storms, 222–223, 249
stratification, 222, 224, 248
temperature, 8, 177, 204–205, 212, 222, 223–224,
248
thermal inertia/expansion of, 64–65, 107, 282
warming over, 4, 51
See also Coastal communities; Coral reefs;
Fisheries; Sea level change
Ocean acidification (OA)*, 8, 209–210, 212,
223–224, 248, 282
pH*, 212, 222, 223
reversal of, 5, 67
risks from, 180, 223–224, 227
Ocean alkalinization, 17, 121, 345–346
Ocean chemistry, 209–210, 223–224
carbonate chemistry, 178, 222, 223
Ocean ecosystems, 8–9, 179, 221–230, 248
blue carbon*, 330, 462
critical thresholds, 179
ecosystem services, 227–229, 228
foodwebs, 226–227, 228, 248
framework organisms, 225–226, 248
impacts, 8, 9, 178, 179, 221–230, 228, 248
ocean circulation and, 223, 248
species range shifts, 222, 248
Ocean fertilization*, 346, 462–463
Organization for Economic Co-operation and
Development (OECD), 373
Overshoot*, 12, 14–15, 18, 51, 100, 179, 265
CDR and, 17, 95
definition, 24
emission reductions and, 13, 14–15, 18, 95, 116
impacts of, 60
irreversible impacts, 61, 179
low-OS vs. high-OS, 100
magnitude and duration of, 179, 265
no or limited overshoot, 12–17, 13, 14–15,
60–61, 62
returning to 1.5°C after overshoot, 5, 17, 61, 96
risks of, 5, 177, 179, 277
Ozone (O3)*, 268
ozone-related mortality, 9, 180, 250
precursors, 98, 118, 241
tropospheric, 236
P
Pacific decadal variability (PDV), 201
Paris Agreement*, 4, 18, 77, 79, 353
aim and context, 54–55, 66, 74, 77, 79, 359
equity principle, 51, 54, 479
goal of adaptation, 359
goal of limiting warming, 51
time horizon for, 74
transparency framework, 361
Pathway archetypes, 99–100, 100, 112–113, 113, 147
cumulative CO2 emissions, 123
electricity generation, 135
land-use change (LUC)*, 126, 145
land use/footprint, 147
primary energy contributions, 130–131, 131
Pathways, 12–17, 49–64, 62–64, 93–174
1.5°C pathways*, 12–17, 14–15, 52, 59–64,
93–174, 100, 160, 265–271, 274–276, 320,
1.SM.4, 1.SM.6
2°C pathways, 96, 100, 101, 102
adaptation pathways*, 64, 70, 396, 458–459
assumptions, 95, 109–112
bioenergy with carbon dioxide capture
and storage (BECCS)*, 17, 96
carbon dioxide removal (CDR)* in, 17, 21, 95, 96,
111, 118–125, 180, 265–266
classification of, 61, 62, 99–100, 100, 113–114, 113
climate-resilient development pathways, 22, 52,
64, 73, 448–449, 450–451, 451, 468–472,
475–476, 479–480, 480
definitions of, 59–61, 63–64
emissions in, 12–17, 13, 14–15, 24, 95, 96
four categories/model pathways, 12, 14–15,
59–61, 62, 63, 265–271
geophysical characteristics, 101–104
implications beyond end of century, 270–271, 278
net-zero CO2 emissions*, 12, 61, 66–68, 116
nexus approaches, 467
no or limited overshoot, 12–17, 13, 14–15, 60–61,
62, 100
non-CO2 mitigation, 265, 268
overshoot pathways, 12, 14–15, 18, 24, 51, 60–61,
62, 100, 277
overview, 108–129
portfolio of measures, 12, 15
prospective mitigation pathways, 60, 63
Representative Concentration Pathways (RCPs)*, 62
scenarios used, 98–100, 100
sector and system transitions, 14–15, 15–16
Shared Socio-economic Pathways (SSPs)*, 62–63,
109–110, 110, 111, 448, 467–468
sustainable development and, 18–23, 98–101
156–157, 156, 463–466, 465
Sustainable Development Pathways, 64, 448–449,
466–472, 469, 479–480
temperature pathways, 59–61, 62, 63
time frame for, 95–96
transformation pathways*, 70, 148–157
transformations, whole-system, 129–148
transitions, speed and scale of, 15, 320, 320, 392
uncertainty, 60, 98
used in this report, 59–61, 62, 63
See also 1.5°C pathways; Climate-resilient
development pathways; Pathway archetypes;
Scenarios
Index
Index
613
Peatlands, 221
Permafrost*, 182, 262, 271
beyond end of century, 271
feedbacks, 103–104, 262
irreversible loss of carbon from, 262, 264
remaining carbon budget and, 12
thawing, 8, 12, 104, 220, 259, 262
tipping points*, 262, 264
pH*. See Ocean acidification
Phenology, 216–218
Philippines, flood measures, 368
Phytoplankton, 224, 226
Policies*, 19, 21–22, 71, 148–150, 317, 372–380
acceptability* of, 22, 368–369
assumptions in 1.5° pathways, 112, 149
car/transport pricing policies, 366
carbon pricing, 95, 317, 375–377, 460
coordination and monitoring of, 449
design and implementation,
71, 321, 359–360, 460
enabling climate finance, 372–380
equity in, 22
innovation, 22
integrated policy packages, 379–380, 383
international agreements, 70, 317
internationally cooperative, 22, 23, 95
investment, 22
knowledge gaps, 391
for low-emission transition, 372–375
mobilization and integration of, 150, 317
national, 316
promoting climate action, 366–368
redistributive, 21, 448
regulatory measures, 377–378
for residual risk and loss and damage, 456
Sustainable Development Goals and, 448
technology, 95, 148, 370–371
See also Governance
Population. See Human population
Poverty*, 9, 53, 180, 182, 244
in 1.5°C warmer worlds*, 447, 451–453
adaptation limits*, 455
avoided impacts of 1.5°C vs. 2°C, 452–453
climate change influence on, 55, 282, 447, 450, 452
disproportionate impacts, 9, 51
energy poverty, 464
increase in, 180
livelihoods* and, 244
multidimensional, 55, 450, 457
Multidimensional Poverty Index, 55
numbers of people at risk, 447, 452
‘poverty scenario’ (SSP4), 452
projections for, 9, 10, 180
Poverty eradication*, 18–23, 55, 72, 445–538
conditions for achieving, 474–475
mitigation pathways and, 22
research gaps, 475–476
sustainable development and, 450
Power asymmetries, 449, 459, 462, 471, 475
Prairie pothole ecosystems, 221, 254
Precipitation, 182, 191–196
extremes, observed, 191–192, 197
extremes, projected, 189, 197, 214–215
extremes, Sub-Saharan Africa, 197
heavy precipitation, 7, 177, 178, 194–196, 195,
211, 255
hotspots, 193, 194
monsoon, 194, 262–263, 264
observed changes, 177, 191–194, 211
projected changes, 7, 178, 187–188, 188, 211
regional, 191–196, 196, 3.SM.2.3.1, 3.SM.2.3.2
runoff*, 201–203, 211
See also Droughts; Floods
Precursors*, 64, 65, 98, 102–103, 118
Pre-industrial*, 24
reference period, 51, 56, 57–59, 81, 184
Procedural equity. See Equity
Pteropods, 224, 226–227, 3.SM.3.2.4
Public acceptability, 22, 317, 368–369
R
Radiative forcing*, 59, 66–67, 188
aerosols*, 102–103
long-lived climate forcers (LLCF)*, 64–66, 66–68,
116–118
natural forcings, 59, 66–67
non-CO2 forcers, 5, 6, 95, 96, 101–103, 103
recent trends, 1.SM.7
short-lived climate forcers (SLCF)*, 64, 66–68, 118,
120, 316
uncertainties in, 96, 101–104, 103
Rainfall. See Precipitation
Reasons for concern (RFCs)*, 10, 11, 181, 182,
251–258, 3.SM.3.3.1-3.SM.3.3.7
RFC1 (Unique and threatened systems), 10, 11,
181, 251, 253–255, 254
RFC2 (Extreme weather events), 10, 11, 181,
251–252, 254, 255
RFC3 (Distribution of impacts), 10, 11, 181,
251–253, 254, 255–256
RFC4 (Global aggregate impacts), 10, 11, 181,
251–254, 254, 256–257
RFC5 (Large scale singular events), 10, 11, 181,
254, 257–258
Recycling, 335, 335, 460
Reducing Emissions from Deforestation and
Forest Degradation (REDD+)*, 329–330
Reference period*, 56–59, 81, 184
periods shorter than 30 years, 51
pre-industrial* temperatures, 51, 56, 57–59
30-year period used, 51, 56
Reforestation*, 17, 70, 121, 265, 266, 270, 316,
343, 394, 395
constraints, 316
incentivization of, 147
trade-offs, 269
Region(s)*, 187
climate differences in, 177–178
cooperation and governance, 353–354
with high risks at 2°C, 247–250
hotspots, 258–260, 261
regions used in this report, 187
tipping points, 262–263, 264
warming of >1.5°C already experienced, 4, 51,
68, 81, 452
See also specific regions and countries
Regional climate change, 68, 177, 188–191
drought*, 198–200, 198, 199, 200–201, 260
runoff*, 201–202, 202, 211
temperatures on land, 188–191, 189, 192, 193,
196, 197
See also Regional impacts; Regional precipitation;
Regional temperatures
Regional impacts, 9, 68, 177–178, 182
crop production, 9, 259, 263
economic growth, 9, 180–181
variation in, 450
Regional precipitation, 191–196, 196
observed changes, 191–194, 3.SM.2.3.1
projected changes, 193, 194–196, 195, 196
3.SM.2.3.2
Sub-Saharan Africa, 197
Regional temperatures, 59, 60, 189–191, 196, 283
observed changes, 189–190, 197, 1.SM.1, 1.SM.3,
3.SM.2.2.1
projected changes, 189, 190–191, 192, 193, 196,
197, 283, 3.SM.2.2
Regulatory measures, 377–378
Remaining carbon budget*, 12, 96, 104–107,
2.SM.1.1.2
1.5°C pathways*, 113–114
agricultural emissions and, 147
assessment of, 104–107, 108
CO2 and non-CO2 contributions, 105–107, 108
definition, 24, 96
overshoot minimization and, 177
permafrost thawing and, 105, 107
uncertainties, 12, 96, 108
Remedial measures, 70–71
Renewable energy, 14, 15, 96, 111, 131, 132–133,
316, 324
acceptability of, 368–369
deployment and scaling up, 461, 464–466
feasibility of, 324
hybrid systems, 326
water demands for, 464
Representative Concentration Pathways (RCPs)*,
62
Resilience*, 316, 456
climate-resilient land use, 333
cultural practices and, 360
See also Climate-resilient development pathways
(CRDPs); Vulnerability
Risk(s)*, 5, 7–10, 177–181, 186–253, 210–212,
247–250
confidence and likelihood qualifiers, 77, 182
de-risking policies and investments, 317, 378–379
definition, 24, 68
ecosystems*, 8–9, 11
factors influencing, 5, 277
with global warming of 1.5°C, compared with
2°C, 5, 7–10, 11, 177–181, 186–253, 210–212,
247–250, 453
human health, 180, 182, 250
interacting and cascading, 245, 452
Index
Index
614
key elements of, 251–253, 252
multi-sector, 246
multiple and compound, 10, 178, 181
to natural and human systems, 178, 179–181,
212–253, 247–250
Reasons for concern (RFCs)*, 10, 11, 181
residual, 454–456
social-ecological systems, 338–341
summary of, 247–250, 251–253
of temperature overshoot, 5, 177, 179
of unavoidable impacts, 455
uncertainty, 77
urban areas, 183
to vulnerable populations, 53
Risk assessment*, 55, 183–186
Risk management*, 336
adaptation* and, 5, 10
Sendai Framework*, 70
See also Disaster risk management
Risk sharing, 316, 336–337, 338, 385
Rotterdam, The Netherlands, adaptation strategy,
341
Runoff*, 178, 201–203, 211
observed changes, 201, 211
projected changes, 201–203, 202, 211
S
Sahel, Africa, projected risks and impacts in, 180,
236, 259, 261, 262–263
Scenarios*, 52, 62–64, 98–100, 276, 277, 279–281
1.5°C- and 2°C scenarios, 98–100, 100, 184
comparison of, 279–281
database of, 99
definition of, 63
emission scenarios*, 184, 276
faster transition scenario, 131, 135
inclusion of CDR in, 277
OECD scenario for 2°C, 373
primary energy supply in, 132–133
socio-economic scenario*, 62–63
SRES, 62
used in this report, 63
See also Narratives; Pathways
Scientific evidence, 52
Scientific institutions, 23, 317, 451
Sea ice*, 182, 205–206, 212, 224–225, 249, 270
Antarctic, 206, 225
Arctic, 8, 178, 205–206, 209, 212, 224, 254, 258,
261, 262
beyond end of century, 270
irreversible changes, 257, 262
temperature overshoot and, 8
as tipping point, 261, 262, 270
Sea level change*, 7–8, 182, 206–207, 212, 225,
231–234, 248, 249
adaptation and, 10
beyond end of century, 271
coastal areas and, 207, 231–234, 243, 248, 249, 252
commitment to continued rise, 7, 51, 67, 207, 257,
271, 282
deltas and estuaries, 232–233
detection and attribution, 252
emissions and, 5, 7, 51
glaciers and, 206
global mean sea level rise, 178, 206–207, 212
ice sheets* and, 7, 178, 206, 208, 257, 271
impacts, 178, 181, 182
migration due to, 232
multi-metre rise, 7, 178, 271
numbers of people at risk, 178, 231, 232, 234, 256
past climate episodes and, 208
projected, for 1.5°C, vs. 2°C, 7–8, 178, 206–207,
207, 212, 231–234, 234
regional, 178, 207, 234
sea level rise, 7–8, 67, 178, 206–207, 225,
231–234, 248, 249, 252
small islands and, 7, 8, 232
time-integrated impacts, 61, 62
UNESCO World Heritage sites at risk, 243
Sea surface temperature (SST)*, 204, 223–224,
248
in definition of 1.5°C, 51
Seagrasses, 225–226, 228, 248, 3.SM.3.2.1
Seasonal warming, 4, 51, 59, 60, 68
Sendai Framework for Disaster Risk Reduction*, 70
Sequestration. See Carbon sequestration
Shared Socio-economic Pathways (SSPs)*, 62–63,
109–110, 110, 111, 448, 467–468
land-use change and, 145
policy assumptions, 149
SDGs and, 321, 448, 467–468
Shipping, 333
Short-lived climate forcers (SLCF)*, 64, 66–68,
118, 120, 316, 341–342
co-benefits of reducing, 342, 342
emission reductions, 67, 316, 341–342
knowledge gaps, 389
main characteristics of, 342
mitigation options*, 341
projected emissions, 96, 157
SDGs and, 157
Singapore, road pricing and car use, 366
Sink*. See Carbon sequestration
Small Island Developing States (SIDS)*, 9,
234–235, 255, 260, 261
adaptation approaches, 339–340
adaptation limits, 235, 455
in Caribbean, 339–340
climate hazards for, 234–235, 471
climate-resilient development pathways* in,
471, 471
disproportionate impacts/risks, 9, 53, 447
flooding, 235
freshwater resources, 9, 213, 234, 235
Kiribati, adaptation in, 368, 471
livelihoods, 232, 235
migration and, 181
multiple, compounded risks, 10, 178, 181,
260, 261
Pacific Islands, indigenous knowledge in, 360
risks, 9, 181, 232, 255
sea level rise and, 7, 8, 232, 234–235
storm damage, 235
tourism, 229
Vanuatu, planning for climate-resilient
development, 449, 471
Snow, 182
Social cost of carbon (SCC)*, 150–151, 265, 375
Social costs*, 67, 265, 317, 365, 375
Social-ecological systems*, 338–341
Social learning*, 449, 475
Social safety nets, 362, 385
Societal choices, 98, 99
Societal (social) transformation.
See Transformation
Socio-economic drivers, 109–110, 110
Socio-economic scenario*, 62–63
Soil carbon sequestration (SCS)*. See Carbon
sequestration
Soil erosion, 216
Soil moisture*, 190, 191, 196
anomalies, 198, 199, 200
Solar energy, 96, 131, 131, 132–133
water use and, 464–466
Solar radiation modification (SRM)*, 12–13, 70–71,
347–349, 349–352
carbon budget and, 351
in context of 1.5°C pathways*, 349–352
feasibility, 347–349, 351–352
governance, 347–348
impacts and ethical issues, 71, 317, 349, 351
knowledge gaps, 390
overview/main characteristics, 348
risks of, 13, 347
social acceptability of, 349
sustainable development and, 351
timing and magnitude, 349–351
uncertainties and limitations, 12–13, 316–317
Southeast Asia, vulnerability and risks in, 259, 261
Southern Ocean, role in global carbon cycle,
257–258
Special Report on 1.5°C. See IPCC Special Report
on 1.5°C (SR1.5)
Species
interactions, phenology and, 216–218
invasive, 8, 9, 223
loss and extinction, 8, 179, 218
range loss/shifts, 8, 179, 218, 222, 247, 248,
256–257
SSPs. See Shared Socio-economic Pathways (SSPs)
Stabilisation (of GHG or CO2-equivalent
concentration)*, 116, 122, 147, 158, 184–185
Stockholm, congestion charge and car use, 366
Storms, 181, 222–223, 249
extratropical, 203–204
storm surge, 223
tropical cyclones, 203–204, 211
Stranded assets*, 18
Structured Expert Dialogue (SED), 79
Sub-national actors*, 23
Sub-Saharan Africa, changes in climate extremes,
197
Sulphur dioxide (SO2), 96, 118, 120
Supply-side measures. See Demand and supply-side
measures
Index
Index
615
Surface air temperature (SAT)
in definition of 1.5°C, 51, 56
global average temperature and, 56–57
Sustainable development (SD)*, 18–23, 72, 73–75,
445–538
and 1.5°C pathways*, 93, 97, 98, 156–157, 253,
450–451, 463–466, 465
and 1.5°C warmer worlds*, 55–56, 447, 451–453
adaptation and, 19, 447, 456–459
avoided impacts and, 452–453, 453, 475
climate-resilient development pathways (CRDPs)*
and, 22, 52, 64, 448–449, 450–451, 451, 468–472,
475–476, 479–480
co-benefits, 447
conditions for achieving, 474–475
definition, 73
equity and, 55–56, 448–449
integration with adaptation and mitigation, 75–76,
448, 467
mitigation and, 12, 18, 19–21, 97, 156–157, 156,
447–448, 459–466, 481–509
mitigation pathways and, 463–466, 465
overview, 450, 475–476
pathways to 1.5°C, 466–472, 469, 479–480
research gaps, 475–476
risks to, 253
in social-ecological systems*, 338–341
synergies and trade-offs, 457–458, 459–463, 463,
475
trajectories, 451, 469–470, 480
transformation* and, 22, 56, 73, 448, 456, 466
Sustainable Development Goals (SDGs)*, 18,
19–21, 73–75, 156–157, 156
adaptation options* and, 457–458
avoided impacts and, 18, 68, 183, 253–265, 447,
453, 475
CDR and, 448, 462
climate change and, 73, 74, 75, 157, 158, 252
energy efficiency and, 448
equity and, 51
food security and nutrition, 238
mitigation options and, 19–21, 20–21, 448,
459–463
mitigation pathways, interactions with, 2.SM.1.5
mitigation-SDG table, 481–509
overview, 450
policy instruments and, 448
prioritizing, 447
risks from 1.5°C, vs. 2°C, 453
SDG Global Index Scores, 53
SDG-interaction scores*, 481–509
Shared Socio-economic Pathways* and, 321, 448,
467–468
synergies and trade-offs, 19–21, 21–22, 319, 447,
463, 475
system transitions and, 317
Sustainable Development Pathways, 64, 448–449,
466–472, 469, 479–480
Synergies, 18–19, 20–21, 72, 269, 316, 477,
4.SM.4.5.1, 4.SM.5.2
adaptation and SDGs, 447
knowledge gaps, 391
mitigation and SDGs, 19–21, 20–21, 157, 459–463,
463, 465
mitigation and sustainable development, 459–463,
463, 475
uneven distribution of, 466
Synfuels, 333
Systemic changes/transitions, 14–15, 15–16, 21–22,
315, 323–349, 449, 476
enabling, 315–318
rates of change, 322–323
See also Transitions
T
Tanzania, indigenous knowledge used in, 360
Technology, 22
access to, 23
biotechnology/genome modification, 319, 329
deployment of, 72
disruptive, 22, 111, 319, 323
general purpose technologies (GPT)*, 369–370, 383
information and communication
technology (ICT)*, 316, 319
innovation in, 19, 21, 22, 316, 369–370
innovation, enabling, 369–372
innovation, examples of, 370
innovation, knowledge gaps, 391
low-carbon, 15, 16, 96, 153, 331
new, 15, 22, 319
policies, 95, 148, 370–371
Power-2-X, 111
smart technology/IoT, 331
standards, 332, 378
Technology transfer*, 19, 23, 371–372, 371, 449, 474
Temperature, 182
carbon budget, emissions, and, 96
datasets, 53, 56, 57, 58, 59, 1.SM.1
fluctuations in, natural, 56, 59
global average, defined, 56–57, 81
global mean surface temperature (GMST)*, 56–57,
57, 177, 186
heat-related morbidity and mortality, 9, 11, 180,
240–241, 250, 252, 252, 263, 264, 3.SM.3.3.1
heatwaves*, 9, 177–178, 263, 264
land-sea contrast in warming, 8, 51, 59, 187, 190, 205
land surface air temperature*, 56
number of hot days, 190, 193, 210
observed warming, 6, 51, 53, 53, 58, 106, 189–191,
1.SM.1, 1.SM.2, 1.SM.3, 1.SM.6
peak in, 5, 96, 101, 104, 177, 277
peak, reducing after, 17, 18, 278
projections, 4, 7, 177, 187–188, 188, 190–191,
192, 193
rate of change, 54, 177, 178
regional variation in, 177, 283
sea surface temperature (SST)*, 51, 204, 223–224,
248
temperatures used in definition of 1.5°C, 51, 187,
188
See also Global warming
Temperature extremes, 255, 263
hotspots (key risks), 190–191, 193
and human health, 263, 264
observed, 210
probability ratio of, 192
projected, 7, 177, 189, 190–191, 192, 210, 255
Sub-Saharan Africa, 197
Temperature overshoot*. See Overshoot
Temperature threshold, 65, 66
Terrestrial ecosystems, 8, 179, 216–221, 247, 252,
3.SM.3.3.7
biomass and carbon stocks, 219, 220
biome shifts, 216, 217, 247, 250
ecosystem function, 219
impacts and risks at 1.5°C, vs. 2°C, 8, 11, 179,
216–221, 247, 251, 252, 3.SM.3.3.7, Table 3.SM.2
knowledge gaps, 272
phenology, 216–218
productivity, 220
regional and ecosystem-specific risks, 219–221
respiration, 219
severe ecosystem changes, 217
Thermohaline circulation. See Atlantic Meridional
Overturning Circulation (AMOC)
Tipping points*, 182, 262–263, 264, 270, 282
identifying, 458
See also Irreversibility
Tourism, 11, 178, 181, 242–243, 253, 3.SM.3.3.2
coastal areas, 229, 253
observed impacts, 181
projected impacts, 181, 242–243, 253
risks, 181, 253
seasonal, 181, 243
Trade-offs, 18–19, 72, 73, 269, 4.SM.4.5.1, 4.SM.5.2
example of, 477
knowledge gaps, 391
mitigation options and sustainable development,
459–463, 465
reconciling, 467
with SDGs, 19, 73
specific mitigation options, 97
uneven distribution of, 466
Transformation*, 22, 52, 70, 73, 112, 129–157, 315,
468–469
1.5°C pathways*, 95, 112–113, 129–148, 448, 472
1.5°C warmer worlds*, 73
challenges, opportunities, and
co-impacts, 148–157
cities/urban areas, 472–474
in climate-resilient development pathways, 468–469
context-specific, 469
energy system, 129–144, 463
FAQ on, 392–393, 393
feasibility of, 52, 72
fundamental elements of, 73
implementing, 276
societal (social) transformation*,
22, 52, 73, 448–449, 466
sustainable development and, 22, 448, 456
trade-offs, 73
upscaling and accelerating, 314
whole systems approach, 392
See also Transitions
Transformation pathways*. See Pathways
Index
Index
616
Transformational adaptation. See Adaptation
Transient climate response*, 184–185
See also Climate sensitivity
Transient climate response to cumulative CO2
emissions (TCRE)*, 96, 104, 106
Transition Movement, 480
Transition Towns (TTs), 473–474
Transitions*, 14–15, 15–16, 21–22, 73, 315–318,
323–349, 4.SM.4.2.1-4.SM.4.2.5,
4.SM.4.3.1-4.SM.4.3.5
adaptation options* supporting, 321, 336–337, 338
enabling, 19, 21–22, 315–318
in energy sector, 15, 96–97, 315, 324–327,
374–375, 4.SM.4.2.1, 4.SM.4.3.1
equity* in, 22
FAQ on, 392–393, 393
in land use, 16, 17, 96, 97, 315, 327–329,
4.SM.4.3.2
policies supporting, 22
risks and ethics, 319
speed and scale of, 15, 314, 317, 320, 320,
322–323, 392, 394
sustainable development and, 22
synergies, 316, 4.SM.5.2
system/sector transitions, 14–15, 15–16, 21–22,
96–97, 315–318, 323–349
See also specific sectors
Transnational emission reduction initiatives
(TERIs), 149
Transport sector, 244, 316, 332–333
biofuels, 325
car/transport pricing policies, 366
decarbonization* of, 316, 461
demotorization, 316, 366, 376
electric vehicle (EV)*, 316, 332–333, 333
electrification of, 332–333, 333, 460
emissions, 96, 114, 142–144, 143
emissions reduction, 366
final energy demand and use, 139, 142–144, 143,
332
impacts of weather and climate on, 244
international transport, 333
investments in, 373–374
road safety for pedestrians, 461
road transport, 142–143, 461
strategies to reduce energy consumption, 142
sustainable transport, 332
technological innovations, 370
transitions, 15–16, 316
transitions, speed and scale of, 320, 320
urban environments, 316, 332
Tropical cyclone*, 203–204, 211
Cyclone Pam, 471
Tundra, 8, 179, 216, 220
tipping points*, 262, 264
U
Uncertainty*, 69, 77
of climate response to mitigation, 60, 63
geophysical, 96, 101–104
in mitigation pathways, 60, 63
propagation of, 3.SM.1.3
Unique and threatened systems, 10, 11, 181, 251,
253–255, 254
United Kingdom Overseas Territories (UKOT), 339
United Nations Framework Convention on
Climate Change (UNFCCC)*, 79, 80, 353
adaptation financing, 21
Conference of the Parties (COP)*, 79
Green Climate Fund, 74, 379
Uptake*. See Carbon sequestration
Urban areas, 180, 241–242, 330–334
adaptation examples, 340–341
adaptation options*, 10, 70, 263, 384–386, 385,
4.SM.4.3.3
agriculture in, 316
demotorization, 316, 366, 376
energy systems, 331
feasibility of adaptation options, 384–386, 385
feasibility of mitigation options, 382
global urbanization, 472
governance, 473
green infrastructure*, 10, 334, 334, 385
heat island effect, 9, 180, 242
heat-related extreme events, 241–242
impacts and risks, 180, 182, 183, 241–242
informal urban settlements, 473
infrastructure, 331, 333
knowledge gaps, 388–389
land use, 316, 333
low-carbon cities, 331
mitigation options*, 4.SM.4.2.3
numbers of people in, 330, 340
peri-urban agriculture, 316
poverty and, 242
risks and risk reduction, 331, 456
sea level rise and, 231–232, 241
transformation* in, 472–474
transformational adaptation, 386
Transition Towns (TTs), 473–474
transitions, 15–16, 316, 330–334, 4.SM.4.2.3,
4.SM.4.3.3
transport, 316, 331, 332–333
urban planning, 148
water services, 316, 334
See also specific cities
Urban heat islands, 9, 180, 242
V
Values, 22, 71, 317, 364–365
re-examination of, 449, 469, 475
societal, 448, 476
value judgements, 55
Vanuatu, planning for climate-resilience, 449, 471
Vector-borne disease, 9, 180, 241
Aedes mosquitoes, 241
Vulnerability*, 69, 447
disproportionate impacts and, 9, 51, 447
factors influencing, 53
international cooperation and, 23
multiple, interrelated climate risks, 10
new vulnerabilities, 10
redistributive policies and, 21
reducing, 19, 447, 457
risks and, 53, 452
sustainable development and, 447
systemic, 22, 447, 457
W
Warm Spell Duration Index (WSDI), 190
Water availability, 178, 213–214
Water cycle. See Hydrological cycle
Water management, 10
Water resources, 179, 182, 213–216, 464–466
bottom-up initiatives, 368
demand for, 464–466
groundwater, 181, 215, 3.SM.3.1.1.3
impacts and risks, 213–216, 247
irrigation, 201, 215, 267, 267, 315, 328, 384, 466
projections, 179
regional, 179, 247
in urban areas, 316, 334
water-energy-food (WEF) nexus, 386–387
water quality, 215–216, 3.SM.3.1.1.4
water temperature, 214
watershed management, 356
See also Precipitation
Water scarcity, 179, 213, 452, 453, 466
Water security, 464–466
Water stress, 9, 181, 247, 452, 466
Well-being*, 18, 180
Bhutan’s happiness index, 387
place-specific adaptation and, 447
well-being for all, 469
Wetlands, 179, 225, 254, 330, Table 3.SM.2
management, 330
methane release from, 12
salinization of, 233
sea level rise and, 233
Wind energy, 96, 131, 131, 132–133
Z
Zero emissions commitment (ZEC), 64–65, 65