WHAT WOULD BE THE IMPACTS OF CLIMATE CHANGE ASSUMING NO, OR SOME, OR MUCH EMISSIONS CONTROL AND SEQUESTRATION?

Transcription

1 WHAT WOULD BE THE IMPACTS OF CLIMATE CHANGE ASSUMING NO, OR SOME, OR MUCH EMISSIONS CONTROL AND SEQUESTRATION? Martin parry Co-Chair, Working Group II, IPCC

2 Global mean temperature predictions Temperature ( C) Year Ensembles of four predictions of global mean temperature resulting from business as usual changes in greenhouse gases following on from observed changes since 1860 (orange curves). The addition of sulphate aerosol cooling is shown in the red curves. Hadley Centre for Climate Prediction and Research

3 Global mean precipitation predictions 8 6 Total precipitation (% change) Ensembles of four predictions of precipitation (rainfall and snowfall) resulting from business as usual changes in greenhouse gases following on from observed changes since 1860 (blue curves). The addition of sulphate aerosol cooling is shown in the green curves. Hadley Centre for Climate Prediction and Research

4 Change in annual temperatures for the 2050s The change in annual temperatures for the 2050s compared with the present day, when the climate model is driven with an increase in greenhouse gas concentrations equivalent to about a 1% increase per year in CO 2. The picture shows the average of four model runs with different starting conditions. Hadley Centre for Climate Prediction and Research

5 Observed change in annual precipitation for the 2050s The change in annual precipitation for the 2050s compared with the present day, when the climate model is driven with an increase in greenhouse gas concentrations equivalent to about a 1% increase per year in CO 2. The picture shows the average of four model runs with different starting conditions. Hadley Centre for Climate Prediction and Research

6 IMPACTS UNDER NO MITIGATION

7 Annual runoff Percentage change in 30-year average annual runoff by the 2080s. University of Southampton

8 Population under extreme water stress Population (millions) s 2050s 2080s Change, due to climate change, in the number of people living in countries with extreme water stress. University of Southampton

9 Crop yield change 2020s, ) 2050s,2080s

10 Cereal production (mmt) Reference scenario Climate change scenario 2020s 2080s 2020s 2080s 2050s 2050s % change in prices from 1990 baseline s 2050s 2080s Projected global cereal production for reference case and the climate change scenario. Percentage change in global cereal prices under the climate change scenario (0 = Projected reference case). Additional millions of people at risk of hunger s 2050s 2080s Additional people at risk of hunger under the climate change scenario (0 = Projected reference case).

11 People at risk from sea-level rise % increase s 2050s 2080s Percentage change in the number of people at risk under the sea-level rise scenario and constant (1990s) protection (left bar) and the sea-level rise scenario and evolving protection (right bar). Middlesex University / Delft Hydraulics

12 IMPACTS UNDER SOME/MUCH MITIGATION

13 Emissions and concentrations of CO 2 from unmitigated and stabilising emission scenarios Anthropogenic CO 2 emissions (GtC/yr) CO concentration (ppm) Unmitigated emissions 750 ppm stabilisation 550 ppm stabilisation Hadley Centre for Climate Prediction and Research

14 Global average temperature rise from unmitigated and stabilising emission scenarios Global temperature change ( C) Unmitigated emissions 750 ppm stabilisation 550 ppm stabilisation Hadley Centre for Climate Prediction and Research

15 Temperature rise Annual average, from the present day to the 2080s c Unmitigated Emissions c Stabilisation of CO 2 at 750ppm c Stabilisation of CO 2 at 550ppm Hadley Centre for Climate Prediction and Research

16 Change in precipitation Annual average, from the present day to the 2080s c Unmitigated Emissions c Stabilisation of CO 2 at 750ppm c Stabilisation of CO 2 at 550ppm Hadley Centre for Climate Prediction and Research

17 Changes in river runoff from the present day to the 2080s Unmitigated emissions University of Southampton Stabilisation of CO 2 at 750 ppm Change in annual runoff (%) Stabilisation of CO 2 at 550 ppm to

18 Changes in water stress from the present day to the 2080s Decreased water stress Increased water stress Billions of people University of Southampton Unmitigated Emissions 750 ppm Stabilisation 550 ppm Stabilisation

19 Changes in crop yield from the present day to the 2080s Potential change in cereal yields (%) No data Unmitigated emissions University of East Anglia Stabilisation of CO 2 at 750 ppm Stabilisation of CO 2 at 550 ppm

20 Global number of people flooded under three emissions scenarios 100 University of Middlesex People flooded (millions/year) s 2050s 2080s Unmitigated emissions 750 ppm stabilisation 550 ppm stabilisation No climate change

21 People flooded by region 60 University of Middlesex 50 People flooded (millions/year) Southern Mediterranean West Africa East Africa South Asia SE Asia Unmitigated emissions 750 ppm stabilisation 550 ppm stabilisation No climate change

22 Island people flooded 600 University of Middlesex People flooded (thousands/year) Caribbean Indian Ocean small islands Pacific small islands Unmitigated emissions 750 ppm stabilisation 550 ppm stabilisation No climate change

23 Malaria transmission Change in duration of season, 2080s Unmitigated emissions London School of Hygiene and Tropical Medicine Stabilisation at 750 ppm Stabilisation at 550 ppm 2 to 5 months 1 to 2 months 2 to 1 months 5 to 2 months

24 Millions at Risk in the 2080s Temperature Increase Legend Risk of water shortage Risk of malaria Risk of hunger Risk of coastal flooding Additional millions of people at risk of hunger, malaria and coastal flooding Stab. 450 Stab. 550 Stab. 650 Stab. 750 Stab Unmitigated emissions - IS92a Additional millions of people at risk of increased water shortage

25 The Cost of Stabilising CO 2 Concentrations

26 The effect of different global economic pathways Regional enterprise: high pop, mod. growth, (A2) Local stewardship: semi - sustainable dev, low pop (B2)

27 A2 in 2050s B2 Pop 11.3 billion GDP 82 tr $ primary energy 970 GJ/yr carbon 16 GtC/yr Pop 9.3 billion GDP 110 tr $ primary energy 870 GJ/yr carbon 11 GtC/yr

28 Additional People at Risk of Hunger under the SRES A2 and B2 Scenarios Additional Millions of People A2 - Regional Enterprise B2 - Local Stewardship

29 Costs of 550 Stabilisation assuming different development pathways ($ trillion) Global Non-ann 1 Annex 1 A B c. 1

30 Conclusions : Stabn at 750 does not avoid most effects. Stabn at 550 does, but at considerable cost (= c.20 times Kyoto reductions). Sustainable development (cf SRES B2 pathway) needs also to be part of the solution

31 The Shortfall in Global Cereal Production for Reference Case and the SRES Scenarios Million Metric Tonnes (mmt) A2 - Regional Enterprise B2 - Local Stewardship

32 Millions at Risk in the 2050s Temperature Increase Legend Risk of water shortage Risk of malaria Risk of hunger Risk of coastal flooding Additional millions of people at risk of hunger, malaria and coastal flooding 550 ppmv 750 ppmv Unmitigated emissions - IS92a Additional millions of people at risk of increased water shortage

33 Conclusions : 2 Invest in adaptation, to increase resilience to climate change: technology (eg GM), engineering (eg water use efficiency), institutions. These are win-win (eg drought-proofing). Invest especially in key vulnerable regions and sectors: Africa, Indian subcont., small islands; water, food, coastal settlement. Revise the adaptation/mitigation emphasis:

34 Change in vegetation biomass from present day to the 2230s ITE Edinburgh c Stabilisation of CO 2 at 750ppm c Stabilisation of CO 2 at 550ppm kgc/m 2

35 Vegetation dieback 5 ITE Edinburgh Area of vegetation dieback (million km 2 ) Years Unmitigated emissions 750 ppm stabilisation 550 ppm stabilisation

36 Uptake of carbon by vegetation 5 ITE Edinburgh 4 Transfer of carbon to vegetation (GtC/yr) Source Sink Unmitigated emissions 750 ppm stabilisation 550 ppm stabilisation

37 Changes in vegetation biomass between the present day and the 2080s Present Day Unmitigated Emission kgc/m 2 Stabilisation of CO2 at 750 ppm kgc/m 2 Stabilisation of CO2 at 550 ppm kgc/m kgc/m 2 ITE Edinburgh

38 Changes in river runoff from the present day to the 2230s University of Southampton c Stabilisation of CO 2 at 750ppm c Stabilisation of CO 2 at 550ppm Change in annual runoff (%) to

39 Changes in water stress from the present day to the 2080s Unmitigated emissions University of Southampton Stabilisation of CO 2 at 750 ppm Stabilisation of CO 2 at 550 ppm Stressed country with decrease in stress Stressed country with increase in stress Country moves to stressed class

40 Conclusions : 3 Foster adaptation to avoid increased inequality (autonomous adaptn=more unequal effects of climate change). Foster increased resilience (especially in the tail ): a) seek the sub-optimal (eg drought resistant/non-max yield crop varieties); b) (many) small vs (few) large actions; c) promote stability (vs growth?).

41 Rate of sea-level rise 60 Rate of sea-level rise (cm/century) s 2050s 2080s 2110s 2140s 2170s 2200s 2230s Unmitigated emissions 750 ppm stabilisation 550 ppm stabilisation

42 Global wetland losses 20 University of Middlesex Fraction of wetland area lost (%) s 2050s 2080s 2110s 2140s 2170s 2200s 2230s Unmitigated emissions 750 ppm stabilisation 550 ppm stabilisation

43 Coastal flooding Change from the present day to the 2080s Unmitigated emissions University of Middlesex Stabilisation at 750 ppm Stabilisation at 550 ppm

44 Malaria transmission season Estimated for the present day (falciparum) London School of Hygiene and Tropical Medicine

45 People at risk of malaria additionally from climate change 350 London School of Hygiene and Tropical Medicine Additional people at risk (millions) s 2050s 2080s Unmitigated emissions 750 ppm stabilisation 550 ppm stabilisation