Global Climate Change: Recent Developments. Pål Prestrud, Director CICERO Centre for International Climate and Environmental Research in Oslo

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1 Global Climate Change: Recent Developments Pål Prestrud, Director CICERO Centre for International Climate and Environmental Research in Oslo 1

2 Changes in global atmospheric temperature during the last 150 years Warmest 12 yrs:1998,2005,2003, 2002,2004,2006,2001,1997, 1995, 199,1990, Source: IPCC

3 Examples of present impacts of global warming Snow and ice are melting Increase in extreme weather events like heat waves and heavy precipitation More frequent droughts in dry areas and more rain in wet areas Large scale changes in distribution of species Sea level rise (3.1 mm/yr) 3

4 Main conclusions of the UN s Climate Panel (IPCC) 2001 and : Most of the observed warming over the last 50 years is likely to have been due to increase in greenhouse gas consentrations 2007: It is very likely that antropogenic greenhouse gas increases caused most of the observed increase in globally averaged temperatures since the mid 20th century. 4

5 Summary of all factors that may explain the warming the last 150 years (IPCC 2007) 5

6 Detection and attribution studies: the models with and without the human factors the last 100 yrs All factors Only natural factors UIt IPCC

7 The IPCC climate scenarios for 2030 and 2100 (IPCC 2007) 7

8 How to predict the future climate? Natural factors 8

9 C 5 CO2-emissions Recent from fossil emissions fuels compared to the IPCC emission scenarios (Raupach et 0 al. 2007, PNAS; Canadell et al. 2007, PNAS) CO 2 Emissions (GtC y -1 ) Actual emissions: CDIAC Actual emissions: EIA 450ppm stabilisation 650ppm stabilisation A1FI A1B A1T A2 B1 B

10 Anthropogenic C Emissions: Land Use Change Carbon Emissions from Tropical Deforestation Pg C yr Africa Latin America S. & SE Asia SUM Pg C y -1 (16% total emissions) Houghton, unpublished 10

11 Atmospheric CO 2 Concentration Annual increase in emissions of CO2 Year 2007 Atmospheric CO 2 concentration: 383 ppm 37% above pre-industrial : 1.3 ppm y : 1.6 ppm y : 1.5 ppm y : 2.0 ppm y : 2.2 ppm y -1 Data Source: Pieter Tans and Thomas Conway, NOAA/ESRL 11

12 Factor (relative to 1990) Drivers of Anthropogenic Emissions Drivers of antropogenic emissions World F Emissions (emissions) P Population (population) g Wealth = G/P = per capita GDP 0.6 h Carbon = F/G intensity of GDP Raupach et al 2007, PNAS

13 % CO 2 Emissions in Atmosphere Decline in the Efficiency of CO 2 Natural Sinks Decline in the efficiency of natural sinks Fraction of all anthropogenic emissions that stay in the atmosphere Emissions 1 tco 2 400Kg stay Emissions 1 tco 2 450Kg stay Canadell et al. 2007, PNAS 13

14 CO 2 flux (Pg C y -1 ) Perturbation of Global Carbon Budget ( ) Sink Source fossil fuel emissions deforestation atmospheric CO 2 land ocean Le Quéré, unpublished; Canadell et al. 2007, PNAS Time (y) 14

15 Probability distribution of climate sensitivity (doubling of CO2) 15

16 What is dangerous climate change? (most scientists would answer above 2-3 C ) The climate conventions aim (Rio 1990) is to prevent human made dangerous climate change. To define dangerous is a value judgement and in the end a political decission Unacceptable increased risk of: Significant reductions in food production and water supply Triggering abrupt irreversible climate change Increase in extreme weather events Melting of the big ice sheets and sea level rise Large scale changes in biodiversity and ecosystems 16

17 Heatwave in Central Europe

18 Observed and modelled (A2 scenario) June-August temperature in Europe (Hadley model) Source: Stott et al Nature

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20 Mtoe World Energy Outlook 2006: Global energy ( 2006 consumption will increase (IEA Other renewables Nuclear Biomass Gas Coal Oil

21 Emisson cuts at different stabilisation levels of CO2 in the atmosphere 21

22 We are able to solve the climate problem without major changes in our welfare (IEA 2006, Stern 2006, IPCC 2007) Existing climate-friendly technologies could solve a significant part of the problem. The potential for further development of exisiting technologies and development of new technologies is large The costs of mitigating emissions of greenhouse gases are low The climate challenge is a political challenge. We must change attitudes 22

23 IEAs scenario for 50% emission cuts in 2050: a technology revolution Source: IEA June

24 Additional investments in the electricity sector at stabilization at 2008-emission levels (ACT-scenario) and at 50% cut in 2050 (BLUE Map scenario) Source: IEA June

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26 Thanks for your attention 26

27 The rate of change is faster than predicted in