1. 1 Hadley Centre for Climate Prediction and Research Tropical vegetation dynamics in simulations of radiatively-forced climate change Richard Betts Hadley Centre for Climate Prediction and Research, Met Office PROMISE 2nd Annual Meeting, Paris, 13th-15th May 2002

2. 2 Hadley Centre for Climate Prediction and Research Hadley Centre Coupled Climate-Carbon Cycle Model

3. 3 Hadley Centre for Climate Prediction and Research TRIFFID-GCM coupling Photosynthesis, respiration, transpiration (30 minutes) Litter (1 day) Competition (10 days) LAI, albedo, roughness (1 day) Broadleaf Tree C3 Grass Shrub Soil

4. 4 Hadley Centre for Climate Prediction and Research Coverage of vegetation types, control simulation Fraction of gridbox

5. 5 Hadley Centre for Climate Prediction and Research Veg cover: simulated - observed (IGBP-DIS) Fraction of gridbox

6. 6 Hadley Centre for Climate Prediction and Research Surface temperature changes (K) relative to 2000 30-year means Prescribed CO 2 (IS92a)

7. 7 Hadley Centre for Climate Prediction and Research Precipitation changes relative to 2000 mm day -1 30-year means Prescribed CO 2 (IS92a) 2020 2050 2080

8. 8 Hadley Centre for Climate Prediction and Research Changes in tree cover Gridbox fraction Prescribed CO 2 (IS92a)

9. 9 Hadley Centre for Climate Prediction and Research Broadleaf tree cover in central Africa

10. 10 Hadley Centre for Climate Prediction and Research Broadleaf tree Net Primary Productivity(NPP) in central Africa

11. 11 Hadley Centre for Climate Prediction and Research Broadleaf tree cover in Indonesia

12. 12 Hadley Centre for Climate Prediction and Research Broadleaf tree NPP in Indonesia

13. 13 Hadley Centre for Climate Prediction and Research Changes in tree cover Gridbox fraction Prescribed CO 2 (IS92a)

14. 14 Hadley Centre for Climate Prediction and Research Change in annual mean precipitation (mm day -1 ) relative to control

15. 15 Hadley Centre for Climate Prediction and Research Change in BL tree cover (%) relative to control

16. 16 Hadley Centre for Climate Prediction and Research Annual mean precip in Manaus gridbox

17. 17 Hadley Centre for Climate Prediction and Research Broadleaf tree cover in Manaus gridbox

18. 18 Hadley Centre for Climate Prediction and Research Broadleaf tree NPP in Manaus gridbox NPP (kg C m -2 s -1 )

19. 19 Hadley Centre for Climate Prediction and Research Broadleaf tree NPP in Manaus gridbox

20. 20 Hadley Centre for Climate Prediction and Research Broadleaf tree cover in Manaus gridbox

21. 21 Hadley Centre for Climate Prediction and Research Precipitation changes due to biogeophysical feedbacks mm day -1 30-year means Prescribed CO 2 (IS92a)

22. 22 Hadley Centre for Climate Prediction and Research Atmospheric CO 2 concentrations — due to business-as-usual emissions (IPCC IS92a) 1000 800 600 400 200 with climate-carbon feedback without climate-carbon feedback 19001950200020502100 CO 2 concentrations (ppmv)

23. 23 Hadley Centre for Climate Prediction and Research Temperature rise over land due to IPCC business-as-usual (IS92a) emissions with CO 2 -climate feedbacks without CO 2 -climate feedbacks 1850 –2 0 2 4 6 8 19001950200020502100 Temperature rise (°C)

24. 24 Hadley Centre for Climate Prediction and Research Further precipitation changes with CO 2 -climate feedback mm day -1 30-year means

25. 25 Hadley Centre for Climate Prediction and Research Further changes in tree cover with CO 2 -climate feedback Gridbox fraction

26. 26 Hadley Centre for Climate Prediction and Research Amazon die-back: is this what happens? CO2  Radiative forcing  El Nino-like SST pattern  Amazon precip  Soil moisture  NPP  Emissions Net C uptake  Forest cover  Stomatal opening  Evapotranspiration Something else!

27. 27 Hadley Centre for Climate Prediction and Research Conclusions Tropical forests may respond to both radiatively-forced climate change and CO 2 fertilisation CO 2 fertilisation may offset climate effects in some regions –are other GHGs “worse” than CO 2 ?? Simulated Amazon drying/dieback is a complex, coupled phenomenon Global climate sensitivity may depends on regional climate and ecosystem changes

28. 28 Hadley Centre for Climate Prediction and Research