Observed and projected climate change – from global to local scale

1. www.bjerknes.uib.no Observed and projected climate change –from global to local scale Helge Drangehelge.drange@gfi.uib.no

2. CO2 in air (from Mauna Loa, Hawaii) CO2 (parts per million)

4. 2008

5. 2009

6. 2010

7. 2011

8. 2012

9. 1912

10. Change in heat content of ocean & land+atm+ice Change in heat (1022 J) Church et al (2011)

11. Change in heat content of ocean & land+atm+ice Change in heat (1022 J) Church et al (2011)

12. Earth´s climate is changing Main reason is our use of coal, oil and gas

13. Possible future uncertainty ≠ no certainty

14. Change in global temperature, 15 models (relative to 1961-1990)

15. Change in global temperature, 15 models (relative to 1961-1990) +2 °C 2025-2050 In 2100: Global: 4.0-5.8 °C Land: 5.0-8.5 °C Future emissions as today (“Business-as-usual”)

16. Change in global temperature, 15 models (relative to 1961-1990) +2 °C 2035-2075 In 2100: Global: 2.0-3.0 °C Land: 2.1-4.8 °C For a global, mean warming of ~2 °C, which we can expect sometime during second half of the 21st century, Earth's climate is comparable to the climate ~3.2 mill years ago Global emission top in 2040, 650 ppm CO2-eq in 2100

17. Drought index based on 14 climate models (2090-2099; RCP4.5) Severe to extreme drought Incr soil moisture Dai, Nature Clim. Change (2012)

18. Over to local scale (where we all live) Much harder to do local than continental/global climate projections! Harder to make projections of precipitation than temperature Very hard to make projections about local changes in extremes

24. Western Norway, 14 September 2005

26. 14 Sep 2005 For Bergen: +30 to +70 % increase in extreme precipitation by the end of the century

27. Photo: Jan M. Lillebø, Bergens Tidende Sea level

28. Warming of the ocean May contribute 15-20 cm in this century Total: +40 to +80 cm in 2100 Cont’d increase “forever” Glaciers melting May contribute 15-20 cm in this century Greenland and Antarctica May contribute 10-40 cm in this century (large uncertainties)

29. Estimated sea level rise (cm) along the coast of Norway, next 100 years (corresponding to a global sea level rise of 50-110 cm) About 1/3 of this rise by 2050 Drange m.fl. (2012)

30. Sea level Will last for > 1000 yr

31. 2-degree target

32. 2-degree target: Consequence of delaying cuts in CO2-emissions (i) CO2-emissions from coal, oil and gas, 1950-2012 Global CO2-emissions (Gt-C) Meinshausen et al. (2009), updated

33. 2-degree target: Consequence of delaying cuts in CO2-emissions (ii) Reduced CO2-emissions from 2013 2013: − 7 % / yr Global CO2-emissions (Gt-C) Meinshausen et al. (2009), updated

34. 2-degree target: Consequence of delaying cuts in CO2-emissions (iii) Reduced CO2-emissions from 2017 2013: − 7 % / yr 2017: −11 % / yr Global CO2-emissions (Gt-C) Meinshausen et al. (2009), updated

35. 2-degree target: Consequence of delaying cuts in CO2-emissions (iv) Reduced CO2-emissions from 2021 2013: − 7 % / yr 2017: −11 % / yr 2021: −22 % / yr Global CO2-emissions (Gt-C) Meinshausen et al. (2009), updated

36. 2-degree target: Consequence of delaying cuts in CO2-emissions (v) Reduced CO2-emissions from 2025 2013: − 7 % / yr ? 2017: −11 % / yr 2021: −22 % / yr 2025: −90 % / yr Global CO2-emissions (Gt-C) Meinshausen et al. (2009), updated

37. About 20 percent of today's CO2-emissions will remain in the atmosphere for 1000 years or more

38. Slides and animations available from helge.drange@gfi.uib.no Earthrise, 24 Dec 1968 (credit: NASA)