Climate Change, Adaptation, and Mitigation after COP21€¦ · Climate Change, Adaptation, and...

Climate Change, Adaptation, and Mitigation after COP21

Jean-Pascal van Ypersele (Université catholique de Louvain, Belgium)

Former IPCC Vice-Chair (2008- oct. 2015)

Twitter: @JPvanYpersele

5th Regional Conference on Climate Change, Tehran, 25-01-2016

Thanks to the Belgian Federal Science Policy Office (BELSPO) and to my team at the Université catholique de Louvain for their support

WhytheIPCC?

toprovidepolicy-makerswithanobjec<vesourceofinforma<onabout

•  causesofclimatechange,•  poten<alenvironmental

andsocio-economicimpacts,

•  possibleresponseop<ons(adapta<on&mi<ga<on).

WMO=WorldMeteorologicalOrganiza<onUNEP=UnitedNa<onsEnvironment

Programme

Established by WMO and UNEP in 1988

What is happening in the climate system?

What are the risks?

What can be done?

IPCC AR5 Synthesis Report

Key messages from IPCC AR5 ! Human influence on the climate system is clear ! Continued emissions of greenhouse gases will increase the likelihood of severe, pervasive and irreversible impacts for people and ecosystems

! While climate change is a threat to sustainable development, there are many opportunities to integrate mitigation, adaptation, and the pursuit of other societal objectives

! Humanity has the means to limit climate change and build a more sustainable and resilient future

Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850.

In the Northern Hemisphere, 1983–2012 was likely the warmest 30-year period of the last 1400 years (medium confidence).

(IPC

C 2

013,

Fig

. SP

M.1

a)

Since 1950, extreme hot days and heavy precipitation have become more common

6

There is evidence that anthropogenic influences, including increasing atmospheric greenhouse gas concentrations, have changed these extremes!

!"#$%&'($'#)&*#%&'+&#,-&)&-'."#$%&'

(Lüthi et al.,2008, NOAA)

+30%

2015

The concentrations of CO2 have increased to levels

unprecedented in at least the last 800,000 years.

1000 years before present

CO

2 Con

cent

ratio

ns (p

pm)

Atmospheric concentrations of CO2!

AR3 AR2

AR1 AR4

A Progression of Understanding: Greater and Greater Certainty in Attribution

AR1 (1990): “unequivocal detection not likely for a decade”

AR2 (1995): “balance of evidence suggests discernible human influence”

AR3 (2001): “most of the warming of the past 50 years is likely (odds 2 out of 3) due to human activities”

AR4 (2007): “most of the warming is very likely (odds 9 out of 10) due to greenhouse gases”

IPCC

/01'234567'89:'(+'&L%-&4&1#$1/6&1#$'2;<<+'=1';>:';?'5447':"#:'">@#$'($A>&$.&''"#+'B&&$':"&'<;@($#$:'.#>+&C'D'

Carbon cycle: unperturbed fluxes

Units: GtC (billions tons of carbon) or GtC/year (multiply by 3.7 to get GtCO2)

120

70.5

70

2300

Atmosphere pre-ind : 597

38000 Ocean

3700

respiration

Physical,

Chemical, and Biological processes

photosynthesis 119.5

vanyp@climate.be

280 ppmv (1ppmv = 2.2 GtC) GtC

Carbon cycle: perturbed by human activities (numbers for the decade 1990-1999s, based on IPCC AR4)

Units: GtC (billions tons of carbon) or GtC/year

120

70.5

70

2300

Atmosphere pre-ind : 597

38000 Ocean

3700

GtC + 3.2/yr

déforestation (& land use changes) Fossil fuels

6.4

-244 +120 -40

1.6 sinks

2.6 respiration

2.2

Physical, Chemical, and

Biological processes

photosynthesis 119.5

vanyp@climate.be Stocks!

280 ppmv + 1.5 ppmv/yr (1ppmv = 2.2 GtC)

RCP Scenarios: Atmospheric CO2 concentration!

AR5, chapter 12. WGI- Adopted version / subject to final copyedit!

Three stabilisation scenarios: RCP 2.6 to 6 One Business-as-usual scenario: RCP 8.5

Only the lowest (RCP2.6) scenario maintains the global surface temperature increase above the pre-industrial level to less than 2°C with at

least 66% probability

(IPC

C 2

013,

Fig

. SP

M.7

a)

18-20000 years ago (Last Glacial Maximum) With permission from Dr. S. Joussaume, in « Climat d’hier à demain », CNRS éditions.

3 km thick ice sheets

Sea level: 120 m lower

Today, with +4-5°C globally With permission from Dr. S. Joussaume, in « Climat d’hier à demain », CNRS éditions.

Transition took 4000 years, not 100 years

E5,7$+>$%&4,&-5%=-&$2"59?&7M$NOPQ3NORS$8/%"$-&7,&2%$%+$PTUQVNOOS$

/9$%"&$W)(UDS$72&95-/+$$

9E!!'FG5'H(I"'/++&++@&$:'0&J;*:'2H($#-'K*#I7'

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/9$%"&$W)(UDS$72&95-/+$$$

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/9$%"&$W)(UDS$72&95-/+$$$

9E!!'FG5'H(I"'/++&++@&$:'0&J;*:'2H($#-'K*#I7'

Climate models project more frequent hot days throughout the 21st century

In many regions, the time between “20-year” (unusually) warm days will decrease

Precipitation projections Annual rainfall projections

!"#$%&' !"#(%)'

Sea level due to continue to increase

(IPC

C 2

013,

Fig

. SP

M.9

)

(Ref: 1986-2005)

IPCC AR5 Synthesis Report

'4,52%7$5-&$51-&50#$=90&-85#$

•! Tropics'to'the'poles •! On'all'continents'and'in'the'ocean •! Affecting'rich'and'poor'countries (but the

poor are more vulnerable everywhere)

AR5 WGII SPM

W/76$G$Y5H5-0$L$Z=19&-5:/1/%#$L$KL,+7=-&$$A[5%-/95$\++0$./2<4C$

/E'E";:;','L(+#'M*#$:N'2"OJPQQ-(+#R*#$:NS.;@Q">**(.#$&,R#:*($#QN+JB$5RT.$5UJ"(<>J&T?=V1:5@N<*7'

IPCC AR5 Synthesis Report

Potential Impacts of Climate Change

*++,'-.,'/-012'34+20-513'

6.721-31,'8+9120:'

6.721-31,',;38<-71=1.0'+>'81+8<1'

"+-30-<'?++,;.5'

AR5 WGII SPM

KeyRiskforAsia

Increasedriskofheat-relatedmortality(highconfidence)

IPCC,AR5,WGII,SPM,p.22

Adapta<onissuesandprospects

1.  Heathealthwarningsystems2.  Urbanplanningtoreduceheatislands;

Improvementofthebuiltenvironment;Developmentofsustainableci<es

3.  Newworkprac<cestoavoidheatstressamongoutdoorworkers

IPCC,AR5,WGII,SPM,p.22

KeyriskDecliningworkproduc<vity,increasingmorbidity(e.g.,dehydra<on,heatstroke,andheatexhaus<on),and

mortalityfromexposuretoheatwaves.Par<cularlyatriskareagriculturalandconstruc<onworkersaswellas

children,homelesspeople,theelderly,andwomenwhohavetowalklonghourstocollectwater(highconfidence)

IPCC,AR5,WGII,TS,p.65

Adapta<onissuesandprospects1.  Adapta<onop<onsarelimitedforpeople

whoaredependentonagricultureandcannotaffordagriculturalmachinery

2.  Adapta<onop<onsarelimitedintheconstruc<onsectorwheremanypoorpeopleworkunderinsecurearrangements

3.  Adapta<onlimitsmaybeexceededincertainareasina+4oCworld

IPCC,AR5,WGII,TS,p.65

KeyRiskforAsiaIncreasedriskofdrought-relatedwaterandfoodshortagecausingmalnutri<on

(highconfidence)

IPCC,AR5,WGII,SPM,p.22

Adapta<onissuesandprospects1.  Disasterpreparednessincludingearly-warning

systemsandlocalcopingstrategies2.  Adap<ve/integratedwaterresource

management3.  Waterinfrastructureandreservoir

development4.  Diversifica<onofwatersourcesincluding

waterre-use5.  Moreefficientuseofwater(e.g.,improved

agriculturalprac<ces,irriga<onmanagement,andresilientagriculture)

IPCC,AR5,WGII,SPM,p.22

Keyrisk

Nega<veimpactsonaveragecropyieldsandincreasesinyieldvariabilitydueto

climatechange(highconfidence)

IPCC,AR5,WGII,TS,p.64

Adapta<onissuesandprospectsProjectedimpactsvaryacrosscropsand

regionsandadapta<onscenarios,withabout10%ofprojec<onsfortheperiod2030–2049showingyieldgainsofmorethan10%,and

about10%ofprojec<onsshowingyieldlossesofmorethan25%,comparedtothelate20thcentury.Aier2050theriskofmoresevereyieldimpactsincreasesanddependsonthe

levelofwarmingIPCC,AR5,WGII,TS,p.64

Regional key risks and potential for risk reduction: Asia (9E!!W'/01W'XEYW'H(%>*&'XEYSZ)

*<++,3' @1-0'/-913' A2+B5403'

Cumulative emissions of CO2 largely determine global mean surface warming by the late 21st century and beyond.

Fig. SPM.10

© IP

CC

201

3

Fig. SPM.10

Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions.

© IP

CC

201

3

IPCC AR5 Synthesis Report

The window for action is rapidly closing 65% of the carbon budget compatible with a 2°C goal is already used NB: this is with a probability greater than 66% to stay below 2°C NB: this is with a probability greater than 66% to stay below 2°C

Amount Used 1870-2011:

1900 GtCO2

Amount Remaining:

1000 GtCO2

Total Carbon Budget:

2900 GtCO2

AR5 WGI SPM NB: Emissions in 2011: 38 GtCO2/yr

F;*R($%'G*;>J'999'.;$:*(B>[;$':;':"&'9E!!'H(I"'/++&++@&$:'0&J;*:'

Can temperature rise still be kept below 1.5 or 2°C (over the 21st century) compared to pre-industrial ? •!Many scenario studies confirm that it is technically and economically feasible to keep the warming below 2°C, with more than 66% probability (”likely chance”). This would imply limiting atmospheric concentrations to 450 ppm CO2-eq by 2100.

•!Such scenarios for an above 66% chance of staying below 2°C imply reducing by 40 to 70% global GHG emissions compared to 2010 by mid-century, and reach zero or negative emissions by 2100.

F;*R($%'G*;>J'999'.;$:*(B>[;$':;':"&'9E!!'H(I"'/++&++@&$:'0&J;*:'

Can temperature rise still be kept below 1.5 or 2°C (over the 21st century) compared to pre-industrial ? •!These scenarios are characterized by rapid improvements of energy efficiency and a near quadrupling of the share of low-carbon energy supply (renewables, nuclear, fossil and bioenergy with CCS), so that it reaches 60% by 2050.

•!Keeping global temperature increase below 1.5°C would require even lower atmospheric concentrations (<430 ppm CO2eq) to have a little more than 50% chance. There are not many scenario studies available that can deliver such results, requiring even faster reductions in the medium term, indicating how difficult this is.

IPCC AR5 Synthesis Report

Mitigation Measures

More efficient use of energy

Greater use of low-carbon and no-carbon energy - Many of these technologies exist today - But worldwide investment in research in support of GHG mitigation is small…

Improved carbon sinks - Reduced deforestation and improved forest management

and planting of new forests - Bio-energy with carbon capture and storage

Lifestyle and behavioural changes AR5 WGIII SPM

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Paris Agreement (COP21)!

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Paris Agreement!

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Paris Agreement!

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Paris Agreement!

INDCs: UNFCCC’s Synthesis Report!

\! X-;`'<;`$';?'&@(++(;$+'%*;`:"'<>&':;'9eK!+P'!! F(:"':"&'9eK!+W'&@(++(;$+'#*&'&VJ&.:&<':;'&d>#-''f1Tg'B^'3431'#$<'U1g'B^'3414';?':"&'8'.#*B;$'B><%&:'D'+($.&'3455':"#:'`;>-<'B&'.;$+(+:&$:'`(:"'hhg'."#$.&+';?'i'3j!'

2010"1990" 2030"

emissions growth"without INDCs"with INDCs #(blue = uncertainty)"

Source : UNFCCC, october 2015"http://unfccc.int/focus/indc_portal/items/9240.php"

46

Intended Nationally Determined Contributions!

\! ke'&@(++(;$+'%#J'*&J;*:'

Baseline

(INDCs)

Unconditional INDCs case

Median estimate of level constant with 2°C

•  Substantial reductions in emissions would require large changes in investment patterns e.g., from 2010 to 2029, in billions US dollars/year: (mean numbers rounded, IPCC AR5 WGIII Fig SPM 9)

•  energy efficiency: +330 •  renewables: + 90 •  power plants w/ CCS: + 40 •  nuclear: + 40 •  power plants w/o CCS: - 60 •  fossil fuel extraction: - 120

IPCC AR5 Synthesis Report

The Choices Humanity Makes Will Create Different Outcomes (and affect prospects for effective adaptation)

With substantial mitigation

Without additional mitigation

Change in average surface temperature (1986–2005 to 2081–2100) AR5 WGI SPM

Mitigation can result in large co-benefits for human health and other societal goals.

Jean-Pascal van Ypersele (vanyp@climate.be)

Useful links: !! www.ipcc.ch : IPCC (reports and videos) !! www.climate.be/vanyp : my slides and other

documents !! www.skepticalscience.com: excellent

responses to contrarians arguments !! On Twitter: @JPvanYpersele and @IPCC_CH