ellisbrown/BDML25SP_hw1_processed_data · Datasets at Hugging Face

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Ice shelf
Ocean heat contentSnow cover
Sea ice
(Arctic)
Abyssal plainO2
Ocean oxygenIce sheet mass
(Greenland & Antarctica)
Cryosphere Changes
Ocean Changes
Deep oceanCarbon dioxideWater
Heat
Ocean circulationCoast
pH
Increase
Decrease
Figure TS.2 \| Schematic illustration of key components and changes of the ocean and cryosphere, and their linkages in the Earth system throug h the global exchange of
heat, water, and carbon (Section 1.2). Climate change-related effects (increase/decrease indicated by arrows in pictograms) in the ocean include sea level rise, increasing
ocean heat content and marine heat waves, increasing ocean oxygen loss and ocean acidiﬁcation (Section 1.4.1). Changes in the c ryosphere include the decline of Arctic sea
ice extent, Antarctic and Greenland ice sheet mass loss, glacier mass loss, permafrost thaw, and decreasing snow cover extent ( Section 1.4.2). For illustration purposes, a few
examples of where humans directly interact with ocean and cryosphere are shown (for more details see Box 1.1).

44Technical Summary
TShigh aciditylow acidityHistorical changes (observed and modelled) and projections under RCP2.6 and RCP8.5 for key indicators
Historical (modelled) Historical (observed) Projected (RCP2.6) Projected (RCP8.5)
−1012345(a) Global mean surface air temperature
change relative to 1986−2005
−6−4−202
(i) Ocean oxygen (100−600 m depth)
%
(j) Arctic sea ice extent
(September)
%
1950 2000 2050 2100(l) Near−surface permafrost area
year1950 2000 2050 2100
yearºC
%change relative to 1986−2005
change relative to 1986−2005
change relative to 1986−2005
year−1012345(b) Global mean sea surface temperatureºCchange relative to 1986−2005
015101520(c) Marine heatwave daysmultiplication factorfactor of change relative to 1986−20057.87.98.08.1
pH(h) Surface ocean pH
00.10.20.3
metres
080016002400(d) Ocean heat content (0−2000 m depth)1021 Joulesand sea level equivalent (right axis)
change relative to 1986−2005
00.10.20.3
(e) Greenland ice sheet mass loss
as sea level equivalent,metres
00.10.20.3
(f) Antarctic ice sheet mass loss
as sea level equivalent,metres
1950 2000 2050 210000.10.20.3
(g) Glacier mass loss
as sea level equivalent,metres
yearchange relative to 1986−2005
change relative to 1986−2005
change relative to 1986−2005
1950
metres*
*
2000 2050 2100 2150 2200 2250 2300012345
primary drivers
(m) Global mean sea level
change relative to 1986− 2005*
*−100−50050
−100−50050100
−100−50050(k) Arctic snow cover extent (June)
%
change relative to 1986−2005
0.43 m0.84 mPast and future changes in the ocean and cryosphere
Figure TS.3

45Technical Summary
TSFigure TS.3 \| Observed and modelled historical changes in the ocean and cryosphere since 19502, and projected future changes under low (RCP2.6) and high (RCP8.5)
greenhouse gas emissions scenarios. Changes are shown for: (a) Global mean surface air temperature change with likely range. {Box SPM.1, Cross-Chapter Box 1 in Chapter 1}
Ocean-related changes with very likely ranges for (b) Global mean sea surface temperature change {Box 5.1, 5.2.2}; (c) Change factor in surface ocean marine heatwave days
{6.4.1}; (d) Global ocean heat content change (0–2000 m depth). An approximate steric sea level equivalent is shown with the right axis by multiplying the ocean heat content
by the global-mean thermal expansion coefﬁcient ( Ƃ ≈ 0.125 m per 1024 Joules3) for observed warming since 1970 {Figure 5.1}; (h) Global mean surface pH (on the total
scale). Assessed observational trends are compiled from open ocean time series sites longer than 15 years {Box 5.1, Figure 5.6, 5.2.2}; and (i) Global mean ocean oxygen change
(100–600 m depth). Assessed observational trends span 1970–2010 centered on 1996 {Figure 5.8, 5.2.2}. Sea level changes with li kely ranges for (m) Global mean sea level
change. Hashed shading reﬂects low conﬁdence in sea level projections beyond 2100 and bars at 2300 reﬂect expert elicitation on the range of possible sea level change {4.2.3,
Figure 4.2}; and components from (e,f) Greenland and Antarctic ice sheet mass loss {3.3.1}; and (g) Glacier mass loss {Cross-Chapter Box 6 in Chapter 2, Table 4.1}. Further
cryosphere-related changes with very likely ranges for (j) Arctic sea ice extent change for September4 {3.2.1, 3.2.2 Figure 3.3}; (k) Arctic snow cover change for June (land areas
north of 60ºN) {3.4.1, 3.4.2, Figure 3.10}; and (l) Change in near-surface (within 3–4 m) permafrost area in the Northern Hemisphere {3.4.1, 3.4.2, Figure 3.10}. Assessments
of projected changes under the intermediate RCP4.5 and RCP6.0 scenarios are not available for all variables considered here, bu t where available can be found in the underlying
report. {For RCP4.5 see: 2.2.2, Cross-Chapter Box 6 in Chapter 2, 3.2.2, 3.4.2, 4.2.3, for RCP6.0 see Cross-Chapter Box 1 in Ch apter 1}
2 This does not imply that the changes started in 1950. Changes in some variables have occurred since the pre-industrial period.
3 This scaling factor (global-mean ocean expansion as sea level rise in metres per unit heat) varies by about 10% between differe nt models, and it will systematically increase
by about 10% by 2100 under RCP8.5 forcing due to ocean warming increasing the average thermal expansion coefﬁcient. {4.2.1, 4.2 .2, 5.2.2}
4 Antarctic sea ice is not shown here due to low conﬁdence in future projections. {3.2.2}snow cover is decreasing ( very high conﬁdence ), and permafrost
temperatures are increasing ( high conﬁdence ). Improvements
since AR5 in observation systems, techniques, reconstructions and model developments, have advanced scientiﬁc characterisation and understanding of ocean and cryosphere change, including in previously
identiﬁed areas of concern such as ice sheets and Atlantic Meridional
Overturning Circulation (AMOC). {1.1, 1.4, 1.8.1, Figure TS.3}
Evidence and understanding of the human causes of climate
warming, and of associated ocean and cryosphere changes,
has increased over the past 30 years of IPCC assessments ( very
high conﬁdence ). Human activities are estimated to have caused
approximately 1.0ºC of global warming above pre-industrial levels
(SR15). Areas of concern in earlier IPCC reports, such as the expected

Ice shelf

Ocean heat contentSnow cover

Sea ice

(Arctic)

Abyssal plainO2

Ocean oxygenIce sheet mass

(Greenland & Antarctica)

Cryosphere Changes

Ocean Changes

Deep oceanCarbon dioxideWater

Heat

Ocean circulationCoast

pH

Increase

Decrease

Figure TS.2 | Schematic illustration of key components and changes of the ocean and cryosphere, and their linkages in the Earth system throug h the global exchange of

heat, water, and carbon (Section 1.2). Climate change-related effects (increase/decrease indicated by arrows in pictograms) in the ocean include sea level rise, increasing

ocean heat content and marine heat waves, increasing ocean oxygen loss and ocean acidiﬁcation (Section 1.4.1). Changes in the c ryosphere include the decline of Arctic sea

ice extent, Antarctic and Greenland ice sheet mass loss, glacier mass loss, permafrost thaw, and decreasing snow cover extent ( Section 1.4.2). For illustration purposes, a few

examples of where humans directly interact with ocean and cryosphere are shown (for more details see Box 1.1).

44Technical Summary

TShigh aciditylow acidityHistorical changes (observed and modelled) and projections under RCP2.6 and RCP8.5 for key indicators

Historical (modelled) Historical (observed) Projected (RCP2.6) Projected (RCP8.5)

−1012345(a) Global mean surface air temperature

change relative to 1986−2005

−6−4−202

(i) Ocean oxygen (100−600 m depth)

%

(j) Arctic sea ice extent

(September)

%

1950 2000 2050 2100(l) Near−surface permafrost area

year1950 2000 2050 2100

yearºC

%change relative to 1986−2005

change relative to 1986−2005

year−1012345(b) Global mean sea surface temperatureºCchange relative to 1986−2005

015101520(c) Marine heatwave daysmultiplication factorfactor of change relative to 1986−20057.87.98.08.1

pH(h) Surface ocean pH

00.10.20.3

metres

080016002400(d) Ocean heat content (0−2000 m depth)1021 Joulesand sea level equivalent (right axis)

change relative to 1986−2005

00.10.20.3

(e) Greenland ice sheet mass loss

as sea level equivalent,metres

00.10.20.3

(f) Antarctic ice sheet mass loss

as sea level equivalent,metres

1950 2000 2050 210000.10.20.3

(g) Glacier mass loss

as sea level equivalent,metres

yearchange relative to 1986−2005

change relative to 1986−2005

1950

metres*

*

2000 2050 2100 2150 2200 2250 2300012345

primary drivers

(m) Global mean sea level

change relative to 1986− 2005*

*−100−50050

−100−50050100

−100−50050(k) Arctic snow cover extent (June)

%

change relative to 1986−2005

0.43 m0.84 mPast and future changes in the ocean and cryosphere

Figure TS.3

45Technical Summary

TSFigure TS.3 | Observed and modelled historical changes in the ocean and cryosphere since 19502, and projected future changes under low (RCP2.6) and high (RCP8.5)

greenhouse gas emissions scenarios. Changes are shown for: (a) Global mean surface air temperature change with likely range. {Box SPM.1, Cross-Chapter Box 1 in Chapter 1}

Ocean-related changes with very likely ranges for (b) Global mean sea surface temperature change {Box 5.1, 5.2.2}; (c) Change factor in surface ocean marine heatwave days

{6.4.1}; (d) Global ocean heat content change (0–2000 m depth). An approximate steric sea level equivalent is shown with the right axis by multiplying the ocean heat content

by the global-mean thermal expansion coefﬁcient ( Ƃ ≈ 0.125 m per 1024 Joules3) for observed warming since 1970 {Figure 5.1}; (h) Global mean surface pH (on the total

scale). Assessed observational trends are compiled from open ocean time series sites longer than 15 years {Box 5.1, Figure 5.6, 5.2.2}; and (i) Global mean ocean oxygen change

(100–600 m depth). Assessed observational trends span 1970–2010 centered on 1996 {Figure 5.8, 5.2.2}. Sea level changes with li kely ranges for (m) Global mean sea level

change. Hashed shading reﬂects low conﬁdence in sea level projections beyond 2100 and bars at 2300 reﬂect expert elicitation on the range of possible sea level change {4.2.3,

Figure 4.2}; and components from (e,f) Greenland and Antarctic ice sheet mass loss {3.3.1}; and (g) Glacier mass loss {Cross-Chapter Box 6 in Chapter 2, Table 4.1}. Further

cryosphere-related changes with very likely ranges for (j) Arctic sea ice extent change for September4 {3.2.1, 3.2.2 Figure 3.3}; (k) Arctic snow cover change for June (land areas

north of 60ºN) {3.4.1, 3.4.2, Figure 3.10}; and (l) Change in near-surface (within 3–4 m) permafrost area in the Northern Hemisphere {3.4.1, 3.4.2, Figure 3.10}. Assessments

of projected changes under the intermediate RCP4.5 and RCP6.0 scenarios are not available for all variables considered here, bu t where available can be found in the underlying

report. {For RCP4.5 see: 2.2.2, Cross-Chapter Box 6 in Chapter 2, 3.2.2, 3.4.2, 4.2.3, for RCP6.0 see Cross-Chapter Box 1 in Ch apter 1}

2 This does not imply that the changes started in 1950. Changes in some variables have occurred since the pre-industrial period.

3 This scaling factor (global-mean ocean expansion as sea level rise in metres per unit heat) varies by about 10% between differe nt models, and it will systematically increase

by about 10% by 2100 under RCP8.5 forcing due to ocean warming increasing the average thermal expansion coefﬁcient. {4.2.1, 4.2 .2, 5.2.2}

4 Antarctic sea ice is not shown here due to low conﬁdence in future projections. {3.2.2}snow cover is decreasing ( very high conﬁdence ), and permafrost

temperatures are increasing ( high conﬁdence ). Improvements

since AR5 in observation systems, techniques, reconstructions and model developments, have advanced scientiﬁc characterisation and understanding of ocean and cryosphere change, including in previously

identiﬁed areas of concern such as ice sheets and Atlantic Meridional

Overturning Circulation (AMOC). {1.1, 1.4, 1.8.1, Figure TS.3}

Evidence and understanding of the human causes of climate

warming, and of associated ocean and cryosphere changes,

has increased over the past 30 years of IPCC assessments ( very

high conﬁdence ). Human activities are estimated to have caused

approximately 1.0ºC of global warming above pre-industrial levels

(SR15). Areas of concern in earlier IPCC reports, such as the expected