World and Asia climate change: Assessment results by IPCC and Japanese supercomputer model predictions LA of AR4 WG1 Chapter 5: Observations: Oceanic Climate Change and Sea Level National Institute for Environmental Studies Center for Global Environmental Research Yukihiro NOJIRI

2 AR4 Publication (Nov.21, 2007)  WG1 The Physical Science Basis, published and pdf available from IPCC web  WG2 Impacts, Adaptation and Vulnerability, pdf available from IPCC web  WG3 Mitigation of Climate Change, pdf available from IPCC web

3  5 Lead Authors and 1 Reviewing Editor for the 3 WGs WG1: Y. Nojiri (LA) and contributors WG2: H. Harasawa (CLA), K. Takahashi (LA), S. Nishioka (RE) and contributors WG3: M. Kainuma (LA), S. Hashimoto (LA) and contriutors NIES research field covers the whole aspect of climate change sciences We have 4 groups of climate change research; carbon cycle, satellite observation, modeling, socio-economic study. NIES Contribution to IPCC AR4

4 IPCC Web Page

5 AR4 is based on the direct obs. of recent climate change Since the TAR (3 rd assessment report), progress in understanding how climate is changing in space and in time has been gained through:  improvements and extensions of numerous datasets and data analyses  broader geographical coverage  better understanding of uncertainties, and  a wider variety of measurements

6 Global mean temperatures are rising faster with time   Warmest 12 years: 1998,2005,2003,2002,2004,2006, 2001,1997,1995,1999,1990,2000 Period Rate Years  /decade

7 Annual averages of the global mean sea level  Averaged global sea level rise for is 1.8mm/y.  Rising rate increased to 3.1 mm/y for  Sea level rise in 20 th century is estimated as 0.17m. Red: reconstructed sea level after 1870 Blue: tide gauge observed sea level after 1950 Black: sea level based on satellite altimetry 20 th century: 1.7±0.5 mm/y 1961 ～ 2003 ： 1.8±0.5 mm/y 1993 ～ 2003 ： 3.1±0.7 mm/y 17cm rise in 20 th century

Smoothed annual anomalies for precipitation (%) over land from 1900 to 2005; other regions are dominated by variability. Land precipitation is changing over broad areas Increases Decreases

9 Global-average radiative forcing estimates and ranges

10  Atmospheric CO 2 is increasing relating to the fossil fuel emission rate.  Atmospheric oxygen gives constraint for estimating terrestrial and oceanic CO 2 sinks.  Atmospheric C isotope change is one of strong evidence of anthropogenic emission. fossil fuel emission C isotope change oxygen/nitrogen ratio atmospheric CO 2 Recent atmospheric CO 2 change

11 1.How will the world socio- economic conditions develop? 2.How much GHGs will be emitted from the society? 3.How much GHGs will be accumulated in the atmosphere? 4.How will the climate change due to increased atmospheric GHGs? 5.How will the climate change affect human society and ecosystem? How to project the future?

12 How will the climate change due to the increased atmospheric GHGs? ‘Climate Model’ = a climate in a computer Discretize atmosphere, ocean, land into ‘grids’ Define physical quantities (wind, temp,..) at each grid Solve equations of physical principles that govern climate ．．． F Q

13 The “Earth Simulator” ©JAMSTEC

14 Climate model and resolution ©JAMSTEC

15 Weather chart from JWA 4/18(initial)4/19(forecast)4/20(forecast) 4/21(forecast)4/22(forecast)4/23(forecast) Weather forecast is solved from the initial condition, therefore it is impossible to project more than a week or so. A A A B B B B B C C C D

16 Averaged feature of weather (i.e. climate) not depends on the initial condition, therefore an ensemble run from many initial conditions can represent future climate. 100 yr projection of Japanese Jan. temperature from 3 initial conditions The difference of initial conditions give different inter-annual variability, however, the trend (e.g. 100 year average of temperature increase) is very simillar.

17 Why the prediction of temperature rise (climate sensitivity) is difficult? Radiative forcing Changes in vapor, snow-ice, cloud … Feedback The magnitude of feedback determines climate sensitivity Cloud feedback is especially uncertain Temperature rise

18 Not purely derived from physical principles (cloud, rain, radiation, small-scale mixing, …) ↓ Half-empirically represented (Source of uncertainty!) How will the climate change due to the increased atmospheric GHGs? ‘Climate Model’ = a climate in a computer Descretize atmosphere, ocean, land into ‘grids’ Define physical quantities (wind, temp,..) at each grid Solve equations of physical principles that govern climate ．．． F Q

19 Simulated Temperature Change ( )

20 Assessed ranges for surface warming (IPCC, 2007 ） Scenario dependence Scientific uncertainty

21 1.Agriculture 2.Water Resources 3.Human health (Infectious diseases and heat stress) 4.Coastal floods (Heavy rainfall and high tide) 5.… Impacts of Climate Change on Human Society

22 Projections of Future Changes in Climate  There is now higher confidence in projected patterns of warming and other regional-scale features, including changes in wind patterns, precipitation, and some aspects of extremes and of ice.

23 Frost days and heat waves  Extreme events like heat wave, draughts or floods are likely to increase in the future climate.  Heat waves may increase globally, especially Mediterranean and Western North America. Frost days (days of minimum temperature of 0C) Heat waves (length of the period of days of 5C higher than climatology) decreasing increasing  Winter warming may be more significant than summer warming.

24 Change of precipitation  Extreme events like heat wave, draughts or floods are likely to increase in the future climate. Precipitation intensity (annual total precipitation/number of wet days) Dry days (annual maximum of consecutive dry day)  Subtropical to mid latitude area may have increasing chance of draught. increasing  Most of the area may have increasing chance of heavy rain fall.

25  JAMSTEC/NIES/University of Tokyo Joint Project  Climate Sensitivity of 4C/CO 2 doubling, which is within the higher sensitivity group in the participated simulation models for IPCC AR4 comparison  Following simulation results are for A1B scenario Climate change movies: by Japanese Earth Simulator

26 Global temperature increase

27 Global precipitation change

28 Sea surface temperature increase

29 Snow cover decrease

30 Projection of 21 th century climate change for each continent from IPCC AR4 report

31 Projection for Asian climate change from IPCC AR4 report

32 Projection for Asian climate change from IPCC AR4 report Tibet India Japan Central Asia Siberia Thailand < global av. T increase > global av. T increase Less precipitation More precipitation

33 Projection for Asian climate change from IPCC AR4 report

34 Robust findings on extreme precipitation and draught from IPCC AR4 report

35 Hotspot of key vulnerabilities in Asia from IPCC AR4 report Please check the WG2 report!

36 Key vulnerabilities in Asia from IPCC AR4 report  Southeast Asia will be vulnerable for Food and fibre, Biodiversity, Coastal ecosystem, Human health and Land degradation by global warming in 21th century  Central Asia is especially vulnerable for Water resource with very high confidence and South Asia for Food and fibre