The Challenges and Opportunities of Climate Change An Overview Based on the IPCC Fifth Assessment Report (AR5)

Transcription

1 The Challenges and Opportunities of Climate Change An Overview Based on the IPCC Fifth Assessment Report (AR5) Jean-Pascal van Ypersele (UCL) IPCC Vice-Chair, Candidate Chair Sheikh Zayed 7th International Seminar, Arabian Gulf University, Bahrain, 26 May 2015 Thanks to the Belgian Federal Science Policy Office (BELSPO) and the Ministry of Foreign Affairs, and to my team at the Université catholique de Louvain for their support

2 $$$$$to$provide$policy3makers$ with$an$objec<ve$source$of$ informa<on$about$$$ causes$of$climate$change,$$ poten<al$environmental$ and$socio3economic$ impacts,$ possible$response$op<ons$ (adapta<on$&$mi<ga<on).$$ $ WMO=World$Meteorological$Organiza<on$ UNEP=$United$Na<ons$Environment$ Programme$$$ $ Why$the$IPCC$?$ Established by WMO and UNEP in 1988 $

3 What is happening in the climate system? What are the risks? What can be done?

4 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 IPCC AR5 Synthesis Report

5 (IPCC 2013, Fig. SPM.1a) Each of the last three decades has been successively warmer at the Earth s surface than any preceding decade since In the Northern Hemisphere, was likely the warmest 30-year period of the last 1400 years (medium confidence).

6 AR5 WGI SPM - Approved version / subject to final copyedit! Change in average surface temperature ! Warming in the climate system is unequivocal!!

7 Aerosol$Op<cal$Depth$from$Remote$ Sensing$$ The$strong$posi<ve$AOD$trend$over$the$ Arabian$Peninsula$occurs$mainly$during$ spring$(mam)$and$summer$(jja),$during$ <mes$of$dust$transport,$and$is$also$visible$in$ MODIS$data.$In#the#2000s#dust,related#AOD# has#been#increasing#over#the#arabian# Peninsula#and#decreasing#over#the#North# Atlan;c#Ocean.# IPCC,$AR5,$WG$I,$Chap.2,$p.175$

8 Aerosol$Op<cal$Depth$from$Remote$ Sensing$$ Aerosol$Op<cal$Depth$trend$(yr 31 )$ IPCC,$AR5,$WG$I,$Chap.2,$p.176$

9 Atmospheric concentrations of CO 2! +30% 2014 CO 2 Concentrations (ppm) 1000 years before present (Lüthi et al.,2008, NOAA) The concentrations of CO 2 have increased to levels unprecedented in at least the last 800,000 years.

10 Tyndall (1861) measures radiation absorption by gases

11 Carbon cycle: unperturbed fluxes Atmosphere pre-ind : 597 GtC 280 ppmv (1ppmv = 2.2 GtC) photosynthesis respiration 70 Physical, 70.5 Chemical, and Biological processes 2300 Ocean vanyp@climate.be Units: GtC (billions tons of carbon) or GtC/year (multiply by 3.7 to get GtCO 2 )

12 Carbon cycle: perturbed by human activities (numbers for the decade s, based on IPCC AR4) Atmosphere 280 ppmv ppmv/yr (1ppmv = 2.2 GtC) pre-ind : 597 GtC + 3.2/yr photosynthesis respiration sinks Physical, Chemical, and Biological processes déforestation (& land use changes) 6.4 Fossil fuels Ocean vanyp@climate.be Units: GtC (billions tons of carbon) or GtC/year Stocks!

13 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 AR5#(2013)#«It#is#extremely$likely$ #(odds#95#out#of#100)#that#human#influence# #has#been#the#dominant#cause #»# AR1 AR2 AR3 AR4 IPCC

14 IPCC AR5 Synthesis Report AR5 SYR SPM

15 Since 1950, extreme hot days and heavy precipitation have become more common 15 There is evidence that anthropogenic influences, including increasing atmospheric greenhouse gas concentrations, have changed these extremes!

16 RCP Scenarios: Atmospheric CO2 concentration! Three stabilisation scenarios: RCP 2.6 to 6 One Business-as-usual scenario: RCP 8.5 AR5, chapter 12. WGI- Adopted version / subject to final copyedit!

17 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 (IPCC 2013, Fig. SPM.7a)

18 Time$series$of$annual$temperature$change$ rela<ve$to$ $averaged$over$land$grid$ points$in$west$asia$$

19 West$Asia:$Maps$of$temperature$ changes$in$ $with$respect$to$ $$in$the$RCP8.5$scenario$$ Regions#where#the#projected#change#is#less#than#one#standard#devia;on#of#the#natural#internal#variability# Regions#where#the#projected#change#is#large#compared#to#natural#internal#variability,#and#where#at#least#90%#of#models#agree#on#a#sign# of#change# IPCC#WG1#FiNh#Assessment#Report#(Final#DraN)#

20 Time$series$of$rela<ve$change$rela<ve$to$ $in$annual$precipita<on$averaged$over$ land$grid$points$in$west$asia$$ IPCC!WG1!Fifth!Assessment!Report!(Final!Draft)!

21 West$Asia:$Maps$of$precipita<on$ changes$in$ $with$respect$to$ $$in$the$RCP8.5$scenario$$ Regions!where!the!projected!change!is!less!than!one!standard!deviation!of!the!natural!internal!variability! Regions!where!the!projected!change!is!large!compared!to!natural!internal!variability,!and!where!at!least!90%!of!models!agree!on!a!sign! of!change! IPCC!WG1!Fifth!Assessment!Report!(Final!Draft)!

22 Future$Regional$Climate$Change$# West$Asia:#This#region#extends#from#the# Mediterranean#to#the#western#fringes#of#South#Asia,# covering#the#middle#east#and#the#arabian$peninsula$ and#includes#large#areas#of#barren#desert.#the$ climate$over$this$region$varies$from$arid$to$semi3 arid$and$precipita<on$is$primarily$received$in$the$ cold$season.$ Land3falling$Tropical$Cyclones$that#occasionally$ influence$the$eastern$part$of$the$arabian$peninsula$ are$notable$extreme$events.## # IPCC,$AR5,$WG$I,$Chap.2,$p.1271$

23 Projected$Major$Changes$in$Rela<on$ to$phenomena$# # Increased$ rainfall$ extremes$of$ landfall$ cyclones$on#the# Arabian# Peninsula.# h"p:// juicy.gossip.fourteen.html8 IPCC,$AR5,$WG$I,$TS,$p.106$

24 (Ref: ) (IPCC 2013, Fig. SPM.9) Le niveau moyen des mers continuera à s élever au cours du XXIe siècle

25 Effets sur le Delta du Nil, où vivent plus de 10 millions de personnes à moins d 1 m d altitude (Time 2001)

26 Potential Impacts of Climate Change Food$and$water$shortages$ Increased$displacement$ of$people$ Increased$poverty$ Coastal$flooding$ AR5 WGII SPM IPCC AR5 Synthesis Report

27 Impacts$are$already$underway$ 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 IPCC AR5 Synthesis Report

28 ADAPTATION IS ALREADY OCCURRING

29 Key$Risk$for$Asia:$Floods$ Increased$riverine,$coastal,$and$urban$flooding$ leading$to$widespread$damage$to$infrastructure,$ livelihoods,$and$seblements$in$asia$(medium$ confidence)8$ $ IPCC,$AR5,$WG$II,$SPM,$p.$22$

30 Adapta<on$issues$and$prospects$ 1. Exposure$reduc<on$via$structural$and$non3 structural$measures,$effec<ve$land3use$planning,$ and$selec<ve$reloca<on$ 2. Reduc<on$in$the$vulnerability$of$lifeline$ infrastructure$and$services$(e.g.,$water,$energy,$ waste$management,$food,$biomass,$mobility,$ local$ecosystems,$telecommunica<ons)$ 3. Construc<on$of$monitoring$and$early$warning$ systems;$measures$to$iden<fy$exposed$areas,$ assist$vulnerable$areas$and$households,$and$ diversify$livelihoods$$ 4. Economic$diversifica<on$$ $ IPCC,$AR5,$WG$II,$SPM,$p.$22$

31 Key$Risk$for$Asia:$Heat$Waves$ Increased$risk$of$heat3related$mortality$ (high$confidence)8$ $ IPCC,$AR5,$WG$II,$SPM,$p.$22$

32 Adapta<on$issues$and$prospects$ 1. Heat$health$warning$systems$$ 2. Urban$planning$to$reduce$heat$islands;$ Improvement$of$the$built$environment;$ Development$of$sustainable$ci<es$$ 3. New$work$prac<ces$to$avoid$heat$stress$ among$outdoor$workers$$ $ IPCC,$AR5,$WG$II,$SPM,$p.$22$

33 Key$Risk$for$Asia:$Droughts$ Increased$risk$of$drought3related$water$ and$food$shortage$causing$malnutri<on$ (high$confidence)"# $ IPCC,$AR5,$WG$II,$SPM,$p.$22$

34 Adapta<on$issues$and$prospects$ 1. Disaster$preparedness$including$early3warning$ systems$and$local$coping$strategies$ 2. Adap<ve/integrated$water$resource$ management$ 3. Water$infrastructure$and$reservoir$ development$ 4. Diversifica<on$of$water$sources$including$ water$re3use$ 5. Moreefficientuseofwater(e.g.,improvedagricult uralprac<ces,irriga<on$management,$and$ resilient$agriculture)$$ $ IPCC,$AR5,$WG$II,$SPM,$p.$22$

35 RISKS OF CLIMATE CHANGE INCREASE WITH CONTINUED HIGH EMISSIONS

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37 IPCC 2013 Fig. SPM.10 Cumulative emissions of CO 2 largely determine global mean surface warming by the late 21st century and beyond.

38 IPCC 2013 Fig. SPM.10 Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions.

39 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 Total Carbon Budget: 2900 GtCO 2 Amount Used : 1900 GtCO 2 Amount Remaining: 1000 GtCO 2 NB: Emissions in 2011: 38 GtCO2/yr AR5 WGI SPM IPCC AR5 Synthesis Report

40 Stabiliza<on$of$atmospheric$concentra<ons$requires$moving$away$from$the$ baseline$ $regardless$of$the$mi<ga<on$goal.$ ~3 C# Based#on#Figure#6.7# AR5 WGIII SPM IPCC AR5 Synthesis Report

41 Limiting Temperature Increase to 2 C Measures exist to achieve the substantial emissions reductions required to limit likely warming to 2 C A combination of adaptation and substantial, sustained reductions in greenhouse gas emissions can limit climate change risks Implementing reductions in greenhouse gas emissions poses substantial technological, economic, social, and institutional challenges But delaying mitigation will substantially increase the challenges associated with limiting warming to 2 C AR5 WGI SPM, AR5 WGII SPM,AR5 WGIII SPM IPCC AR5 Synthesis Report

42 Mitigation Measures More efficient use of energy Greater use of low-carbon and no-carbon energy Many of these technologies exist today 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 IPCC AR5 Synthesis Report

43 All sectors and regions have the potential to contribute by 2030 (avoided emissions: the higher, the better) IPCC AR4 (2007) Note: estimates do not include non-technical options, such as lifestyle changes. IPCC

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

45 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 ( to ) AR5 WGI SPM IPCC AR5 Synthesis Report

46 Sustainable development and equity provide a basis for assessing climate policies and highlight the need for addressing the risks of climate change Issues of equity, justice, and fairness arise with respect to mitigation and adaptation AR5, WGIII, SPM

47 Useful links: : IPCC (reports and videos) : my slides and other documents, including my platform for IPCC excellent responses to contrarians arguments On Jean-Pascal van Ypersele (vanyp@climate.be)