Analysis of Climate Change in India: The Physical Climate

1. Analysis of Climate Change in India: The Physical Climate Richard B. Rood August 31, 2009 rbrood@umich.edu http://aoss.engin.umich.edu/people/rbrood

2. Outline of talk • Basic Background • Global Projections • Global Warming and India • Geography and weather and climate • Projections • Consequences • Summary • Background material

3. Global Warming: The foundation • We release gases into the atmosphere that trap heat close to the surface of the Earth. • This is the greenhouse effect • This, on average, heats the surface of the Earth. • The primary greenhouse gases are water, carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4), and chlorofluorocarbons. • The process of warming by these greenhouse gases is well known, simple, and easily quantified. • The response of the Earth to this warming is complex.

4. Increase of Atmospheric Carbon Dioxide (CO2) Primary increase comes from burning fossil fuels – coal, oil, natural gas Data and more information

5. Carbon dioxide (CO2) facts • Current values about 400 parts per million (ppm) • Prior to industrial revolution about 280 ppm • The oscillation each year is due to breathing of the plants in Northern Hemisphere. Decreases in spring and summer, increases in fall and winter.

6. Global Warming Information • Definitive, community reference is the Fourth Assessment Report (AR4) from the Intergovernmental Panel on Climate Change. • Working Group 1: Scientific Basis • Working Group 2: Impacts and Adaptation • Working Group 3: Mitigation • Synthesis Report • Current Science: Indian Academy of Sciences (2006)

7. Science, Mitigation, Adaptation Framework Adaptation is responding to changes that might occur from added CO2 It’s not an either / or argument. Mitigation is controlling the amount of CO2 we put in the atmosphere.

8. Some definitions (more… ) • Mitigation: The notion of limiting or controlling emissions of greenhouse gases so that the total accumulation is limited. • Adaptation: The notion of making changes in the way we do things to adapt to changes in climate. • Resilience: The ability to adapt. • Geo-engineering: The notion that we can manage the balance of total energy of the atmosphere, ocean, ice, and land to yield a stable climate in the presence of changing greenhouse gases.

9. Global Projections • Basic Background • Global Projections • Global Warming and India • Geography and weather and climate • Projections • Consequences • Summary • Background material

10. IPCC projections for the next 100 years. Emission Scenarios Figure SPM5: IPCC SummPolMaker

11. Latitudinal Variation of Temperature Increase Figure 10.8: IPCC Working Group 1 EMISSIONS TIME

12. Global Warming Facts • The warming increases more at the poles, more in the north than the south. • In the next 20 – 30 years the difference between the different emission scenarios is small. • In 100 years the difference between the emission scenarios is large.

13. Global Warming and India • Basic Background • Global Projections • Global Warming and India • Geography and weather and climate • Projections • Consequences • Summary • Background material

14. Global Warming - with certainty • The temperature will rise. (Global mean, A1B, 2.5 C, 2080-2099 ) • Ice will melt, and sea level will rise. • The weather will change.

15. What defines India’s climate? • First the geography and how it affects climate • And, ultimately, climate change

16. Important attributes of geography Middle Latitudes Large Land Mass Steep Mountains Tropics Large, Warm Source of Water NOAA/NGDC: This and many other maps

17. Monsoonal Flow Dry Season / Winter Wet Season / Summer

18. Tropical ocean important to onset of monsoon rains We do not model tropical structure and variability very well, especially in the Indian Ocean. Hence, our knowledge about changes in monsoon onset have high uncertainty. How tropical convection “organizes” El Nino Madden-Julian Oscillation La Nina

19. Global Warming and India: Projections • Basic Background • Global Projections • Global Warming and India • Geography and weather and climate • Projections • Consequences • Summary • Background material

20. India / South Asia • South Asia temperature will likely be above the global average (3.3 C versus 2.5 C) • Largest change in December, January, February • Increase in number of VERY hot days • Increase in night time temperature • Increases larger towards north and in the interior • South Asia will very likely have fewer cold days. • Extreme precipitation and winds associated with tropical storms will likely increase. • Monsoonal flows will likely decrease in strength.

21. Precipitation • Precipitation increases in wet season / summer. • Precipitation decreases in dry season / winter. • Monsoonal precipitation will likely increase. Why? • increased moisture in the warmer atmosphere • Surface hydrology • Available water? • Warmer temperatures will dry. Often evaporation overwhelms increase in precipitation.

22. IPCC: Asia Climate Change Predictions Figure 11.9: IPCC Working Group 1 TEMPERATURE PRECIPITATION # of MODELS ANNUAL WINTER SUMMER

23. Global Warming and India: Consequences • Basic Background • Global Projections • Global Warming and India • Geography and weather and climate • Projections • Consequences • Summary • Background material

24. Climatology DRYING DESERTFICATION? 2100 ARID 2100 SEMI-ARID TROPICAL WET & DRY MOIST SUBTROPICAL TROPICAL WET

25. Water stored in snow and ice Snowpack and ice receding, lasting shorter amount of time. Disappearing?

26. Rivers • Sea level rise will lead to increased coastal inundation • Amplified by stronger tropical cyclones • Large impact in river deltas • Salt water intrusion • Snow and ice melt • Excess spring flow, flood • Rivers become seasonal

27. Summary • Basic Background • Global Projections • Global Warming and India • Geography and weather and climate • Projections • Consequences • Summary • Background material

28. Summary • Basic physics of climate and climate change in India are solid – warming, snow melt, drought, flood on robust foundation. • Climate change often amplifies existing stresses, especially those related to water resources. • Quality of projections offer motivation and opportunity to prepare. • Complicating Issues (not known or modeled very well) • Tropical dynamics • Indian ocean tropical convection • Madden-Julian Oscillation • El Nino / La Nina • Melting snow / water • Aerosols / Air quality Strongly correlated with details of monsoon behavior, e.g. time of onset.

29. Good Review References • Definitive, community reference is the Fourth Assessment Report (AR4) (2007) from the Intergovernmental Panel on Climate Change. • Current Science: Indian Academy of Sciences (2006)

30. Background Material • Basic Background • Global Projections • Global Warming and India • Geography and weather and climate • Projections • Consequences • Summary • Background material

31. Good Review References • Definitive, community reference is the Fourth Assessment Report (AR4) (2007) from the Intergovernmental Panel on Climate Change. • Current Science: Indian Academy of Sciences (2006)

32. Precipitation 200 cm 150 cm 100 cm 75 cm 50 cm Back to Outline 25 cm

33. Precipitation Back to Outline

34. Monsoon onset Back to Outline

35. Relief map (B&W) Back to Outline

36. Relief Map (color) Back to Outline