Download 20090831_Analysis_Climate_Change_India

Analysis of Climate Change in India:
The Physical Climate
Richard B. Rood
August 31, 2009
[email protected]
http://aoss.engin.umich.edu/people/rbrood
Outline of talk
• Basic Background
• Global Projections
• Global Warming and India
– Geography and weather and climate
– Projections
– Consequences
• Summary
• Background material
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.
Increase of Atmospheric Carbon Dioxide (CO2)
Primary
increase comes
from burning
fossil fuels –
coal, oil,
natural gas
Data and more information
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.
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)
Science, Mitigation, Adaptation Framework
It’s not an either / or argument.
Adaptation is responding to changes that might occur from added CO2
Mitigation is controlling the amount of CO2 we put in the atmosphere.
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.
Global Projections
• Basic Background
• Global Projections
• Global Warming and India
– Geography and weather and climate
– Projections
– Consequences
• Summary
• Background material
IPCC projections for the next 100 years.
Figure SPM5: IPCC SummPolMaker
Emission Scenarios
Latitudinal Variation of Temperature Increase
Figure 10.8: IPCC Working Group 1
EMISSIONS
TIME
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.
Global Warming and India
• Basic Background
• Global Projections
• Global Warming and India
– Geography and weather and climate
– Projections
– Consequences
• Summary
• Background material
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.
What defines India’s climate?
• First the geography and how it affects
climate
– And, ultimately, climate change
Important attributes of geography
Middle
Latitudes
Large Land Mass
Tropics
Large,
Warm
Source of
Water
NOAA/NGDC: This and many other maps
Steep
Mountains
Monsoonal Flow
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
La Nina
Global Warming and India: Projections
• Basic Background
• Global Projections
• Global Warming and India
– Geography and weather and climate
– Projections
– Consequences
• Summary
• Background material
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.
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.
IPCC: Asia Climate Change Predictions
Figure 11.9: IPCC Working Group 1
TEMPERATURE
PRECIPITATION
# of MODELS
ANNUAL
WINTER
SUMMER
Global Warming and India: Consequences
• Basic Background
• Global Projections
• Global Warming and India
– Geography and weather and climate
– Projections
– Consequences
• Summary
• Background material
Climatology
DRYING
DESERTFICATION?
ARID
2100
2100
SEMI-ARID
TROPICAL WET & DRY
MOIST SUBTROPICAL
TROPICAL WET
Water stored in snow and ice
Snowpack and ice receding, lasting
shorter amount of time.
Disappearing?
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
Summary
• Basic Background
• Global Projections
• Global Warming and India
– Geography and weather and climate
– Projections
– Consequences
• Summary
• Background material
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
Strongly correlated with details of
• Madden-Julian Oscillation
monsoon behavior, e.g. time of onset.
• El Nino / La Nina
– Melting snow / water
– Aerosols / Air quality
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)
Background Material
• Basic Background
• Global Projections
• Global Warming and India
– Geography and weather and climate
– Projections
– Consequences
• Summary
• Background material
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)
Precipitation
Back to Outline
200 cm
150 cm
100 cm
75 cm
50 cm
25 cm
Precipitation
Back to Outline
Monsoon onset
Back to Outline
Back to Outline
Relief map (B&W)
Back to Outline
Relief Map (color)