ellisbrown/BDML25SP_hw1_processed_data

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acceleration of sea level rise, are now observed ( high conﬁdence ).
Evidence for expected slow-down of AMOC is emerging in sustained observations and from long-term palaeoclimate reconstructions (medium conﬁdence ), and may be related with anthropogenic forcing
according to model simulations, although this remains to be properly
attributed. Signiﬁcant sea level rise contributions from Antarctic ice
sheet mass loss ( very high conﬁdence ), which earlier reports did not
expect to manifest this century, are already being observed. {1.1, 1.4}
Ocean and cryosphere changes and risks by the end-of-century
(2081–2100) will be larger under high greenhouse gas emission scenarios, compared with low emission scenarios ( very high
conﬁdence ). Projections and assessments of future climate, ocean
and cryosphere changes in the Special Report on the Ocean and
Cryosphere in a Changing Climate (SROCC) are commonly based
on coordinated climate model experiments from the Coupled Model
Intercomparison Project Phase 5 (CMIP5) forced with Representative
Concentration Pathways (RCPs) of future radiative forcing. Current
emissions continue to grow at a rate consistent with a high emission
future without effective climate change mitigation policies (referred
to as RCP8.5). The SROCC assessment contrasts this high greenhouse
gas emission future with a low greenhouse gas emission, high
mitigation future (referred to as RCP2.6) that gives a two in three
chance of limiting warming by the end of the century to less than 2
oC
above pre-industrial. {Cross-Chapter Box 1 in Chapter 1, Table TS.2} Characteristics of ocean and cryosphere change include
thresholds of abrupt change, long-term changes that cannot be avoided, and irreversibility ( high conﬁdence ). Ocean warming,
acidiﬁcation and deoxygenation, ice sheet and glacier mass loss, and
permafrost degradation are expected to be irreversible on time scales
relevant to human societies and ecosystems. Long response times
of decades to millennia mean that the ocean and cryosphere are
committed to long-term change even after atmospheric greenhouse
gas concentrations and radiative forcing stabilise ( high conﬁdence ).
Ice-melt or the thawing of permafrost involve thresholds (state
changes) that allow for abrupt, nonlinear responses to ongoing
climate warming ( high conﬁdence ). These characteristics of ocean
and cryosphere change pose risks and challenges to adaptation.
{1.1, Box 1.1, 1.3}
Societies will be exposed, and challenged to adapt, to changes
in the ocean and cryosphere even if current and future efforts to reduce greenhouse gas emissions keep global warming well below 2ºC ( very high conﬁdence ). Ocean and cryosphere-related
mitigation and adaptation measures include options that address the
causes of climate change, support biological and ecological adaptation, or enhance societal adaptation. Most ocean-based local mitigation and adaptation measures have limited effectiveness to mitigate climate change and reduce its consequences at the global scale, but are useful to implement because they address local risks, often have
co-beneﬁts such as biodiversity conservation, and have few adverse
side effects. Effective mitigation at a global scale will reduce the need
and cost of adaptation, and reduce the risks of surpassing limits to
adaptation. Ocean-based carbon dioxide removal at the global scale
has potentially large negative ecosystem consequences. {1.6.1, 1.6.2,
Cross-Chapter Box 2 in Chapter 1, Figure TS.4}
The scale and cross-boundary dimensions of changes in the
ocean and cryosphere challenge the ability of communities,
cultures and nations to respond effectively within existing
governance frameworks ( high conﬁdence ). Profound economic
and institutional transformations are needed if climate-resilient
development is to be achieved ( high conﬁdence ). Changes in
the ocean and cryosphere, the ecosystem services that they provide,

46Technical Summary
TSTable TS.2 \| Projected change in global mean surface air temperature and key ocean variables for the near-term (2031–2050) and end-of-century (2081–2100) relative to
the recent past (1986–2005) reference period from CMIP5. Small differences in the projections given here compared with AR5 reﬂect differences in the number of models
available now compared to at the time of the AR5 assessment (for more details see Cross-Chapter Box 1 in Chapter 1).
Near-term: 2031–2050 End-of-century: 2081–2100
Scenario Mean 5–95% range Mean 5–95% range
Global Mean Surface
Air Temperature (ºC)aRCP2.6 0.9 0.5–1.4 1.0 0.3–1.7
RCP4.5 1.1 0.7–1.5 1.8 1.0–2.6
RCP6.0 1.0 0.5–1.4 2.3 1.4–3.2
RCP8.5 1.4 0.9–1.8 3.7 2.6–4.8
Global Mean Sea Surface
Temperature (ºC)b
(Section 5.2.5)RCP2.6 0.64 0.33–0.96 0.73 0.20–1.27
RCP8.5 0.95 0.60–1.29 2.58 1.64–3.51
Surface pH (units)b
(Section 5.2.2.3)RCP2.6 –0.072 –0.072 to –0.072 –0.065 –0.065 to –0.066
RCP8.5 –0.108 –0.106 to –0.110 –0.315 –0.313 to –0.317
Dissolved Oxygen
(100–600 m) (% change)(Section 5.2.2.4)
bRCP2.6 –0.9 –0.3 to –1.5 –0.6 0.0 to –1.2
RCP8.5 –1.4 –1.0 to –1.8 –3.9 –2.9 to –5.0
Notes:
a Calculated following the same procedure as the IPCC 5th Assessment Report (AR5). The 5–95% model range of global mean surface air temperature across CMIP5 projections
was assessed in AR5 as the likely range, after accounting for additional uncertainties or different levels of conﬁdence in models.
b The 5–95% model range for global mean sea surface temperature, surface pH and dissolved oxygen (100–600 m) as referred to in t he SROCC assessment as the very likely
range (see also Chapter 1, Section 1.9.2, Figure 1.4).
Actions to reduce
Hazards
RiskVulnerability
ExposureHazardActions to reduce
Vulnerability
Actions to reduce
Exposure
Limits to Adaptation
• E.g. physical, ecological, technological,
economic, political, institutional, psychological, and/or socio-culturalExamples include:
•Coastal retreat and resettlement
•Risk sensitive land use planning
•Early warning systems and
evacuationsExamples include:
•Social protection
• Livelihood diversification
•Insurance solutions
•Hazard-proof housing
and infrastructureExamples include:
• Ecosystem-based measures
to reduce coastal flooding

acceleration of sea level rise, are now observed ( high conﬁdence ).

Evidence for expected slow-down of AMOC is emerging in sustained observations and from long-term palaeoclimate reconstructions (medium conﬁdence ), and may be related with anthropogenic forcing

according to model simulations, although this remains to be properly

attributed. Signiﬁcant sea level rise contributions from Antarctic ice

sheet mass loss ( very high conﬁdence ), which earlier reports did not

expect to manifest this century, are already being observed. {1.1, 1.4}

Ocean and cryosphere changes and risks by the end-of-century

(2081–2100) will be larger under high greenhouse gas emission scenarios, compared with low emission scenarios ( very high

conﬁdence ). Projections and assessments of future climate, ocean

and cryosphere changes in the Special Report on the Ocean and

Cryosphere in a Changing Climate (SROCC) are commonly based

on coordinated climate model experiments from the Coupled Model

Intercomparison Project Phase 5 (CMIP5) forced with Representative

Concentration Pathways (RCPs) of future radiative forcing. Current

emissions continue to grow at a rate consistent with a high emission

future without effective climate change mitigation policies (referred

to as RCP8.5). The SROCC assessment contrasts this high greenhouse

gas emission future with a low greenhouse gas emission, high

mitigation future (referred to as RCP2.6) that gives a two in three

chance of limiting warming by the end of the century to less than 2

oC

above pre-industrial. {Cross-Chapter Box 1 in Chapter 1, Table TS.2} Characteristics of ocean and cryosphere change include

thresholds of abrupt change, long-term changes that cannot be avoided, and irreversibility ( high conﬁdence ). Ocean warming,

acidiﬁcation and deoxygenation, ice sheet and glacier mass loss, and

permafrost degradation are expected to be irreversible on time scales

relevant to human societies and ecosystems. Long response times

of decades to millennia mean that the ocean and cryosphere are

committed to long-term change even after atmospheric greenhouse

gas concentrations and radiative forcing stabilise ( high conﬁdence ).

Ice-melt or the thawing of permafrost involve thresholds (state

changes) that allow for abrupt, nonlinear responses to ongoing

climate warming ( high conﬁdence ). These characteristics of ocean

and cryosphere change pose risks and challenges to adaptation.

{1.1, Box 1.1, 1.3}

Societies will be exposed, and challenged to adapt, to changes

in the ocean and cryosphere even if current and future efforts to reduce greenhouse gas emissions keep global warming well below 2ºC ( very high conﬁdence ). Ocean and cryosphere-related

mitigation and adaptation measures include options that address the

causes of climate change, support biological and ecological adaptation, or enhance societal adaptation. Most ocean-based local mitigation and adaptation measures have limited effectiveness to mitigate climate change and reduce its consequences at the global scale, but are useful to implement because they address local risks, often have

co-beneﬁts such as biodiversity conservation, and have few adverse

side effects. Effective mitigation at a global scale will reduce the need

and cost of adaptation, and reduce the risks of surpassing limits to

adaptation. Ocean-based carbon dioxide removal at the global scale

has potentially large negative ecosystem consequences. {1.6.1, 1.6.2,

Cross-Chapter Box 2 in Chapter 1, Figure TS.4}

The scale and cross-boundary dimensions of changes in the

ocean and cryosphere challenge the ability of communities,

cultures and nations to respond effectively within existing

governance frameworks ( high conﬁdence ). Profound economic

and institutional transformations are needed if climate-resilient

development is to be achieved ( high conﬁdence ). Changes in

the ocean and cryosphere, the ecosystem services that they provide,

46Technical Summary

TSTable TS.2 | Projected change in global mean surface air temperature and key ocean variables for the near-term (2031–2050) and end-of-century (2081–2100) relative to

the recent past (1986–2005) reference period from CMIP5. Small differences in the projections given here compared with AR5 reﬂect differences in the number of models

available now compared to at the time of the AR5 assessment (for more details see Cross-Chapter Box 1 in Chapter 1).

Near-term: 2031–2050 End-of-century: 2081–2100

Scenario Mean 5–95% range Mean 5–95% range

Global Mean Surface

Air Temperature (ºC)aRCP2.6 0.9 0.5–1.4 1.0 0.3–1.7

RCP4.5 1.1 0.7–1.5 1.8 1.0–2.6

RCP6.0 1.0 0.5–1.4 2.3 1.4–3.2

RCP8.5 1.4 0.9–1.8 3.7 2.6–4.8

Global Mean Sea Surface

Temperature (ºC)b

(Section 5.2.5)RCP2.6 0.64 0.33–0.96 0.73 0.20–1.27

RCP8.5 0.95 0.60–1.29 2.58 1.64–3.51

Surface pH (units)b

(Section 5.2.2.3)RCP2.6 –0.072 –0.072 to –0.072 –0.065 –0.065 to –0.066

RCP8.5 –0.108 –0.106 to –0.110 –0.315 –0.313 to –0.317

Dissolved Oxygen

(100–600 m) (% change)(Section 5.2.2.4)

bRCP2.6 –0.9 –0.3 to –1.5 –0.6 0.0 to –1.2

RCP8.5 –1.4 –1.0 to –1.8 –3.9 –2.9 to –5.0

Notes:

a Calculated following the same procedure as the IPCC 5th Assessment Report (AR5). The 5–95% model range of global mean surface air temperature across CMIP5 projections

was assessed in AR5 as the likely range, after accounting for additional uncertainties or different levels of conﬁdence in models.

b The 5–95% model range for global mean sea surface temperature, surface pH and dissolved oxygen (100–600 m) as referred to in t he SROCC assessment as the very likely

range (see also Chapter 1, Section 1.9.2, Figure 1.4).

Actions to reduce

Hazards

RiskVulnerability

ExposureHazardActions to reduce

Vulnerability

Actions to reduce

Exposure

Limits to Adaptation

• E.g. physical, ecological, technological,

economic, political, institutional, psychological, and/or socio-culturalExamples include:

•Coastal retreat and resettlement

•Risk sensitive land use planning

•Early warning systems and

evacuationsExamples include:

•Social protection

• Livelihood diversification

•Insurance solutions

•Hazard-proof housing

and infrastructureExamples include:

• Ecosystem-based measures

to reduce coastal flooding