4. What is Climate? What is weather?
• Climate (from Ancient Greek klima,
meaning inclination) is commonly
defined as the weather averaged
over a long period of time
• Weather is a set of all the
phenomena occurring in a given
atmosphere at a given time.
6. The basis in Science
Intergovernmental
Panel on Climate
Change
(IPCC)
1988
7. The basis in Science
IPCC reports
The main activity of the IPCC is
to provide
Assessment Reports
in regular intervals
on the state of knowledge
on climate change.
8. The basis in Science
Assessment Report
1990
Second Assessment Report
1995
Third Assessment Report TAR
2001
Fourth Assessment Report AR4
2007
9. The basis in Science
Working Group I (WGI)
assesses the physical
scientific aspects
details of recent changes: temperatures,
rainfall, glaciers and ice sheets
greenhouse gases and aerosols;
extent to which they affect climate
10. The basis in Science
Working Group II (WGII)
assesses the vulnerability of
socio-economic and natural
systems to climate change
outlines options for adaptation
11. The basis in Science
Task Force on
National
Greenhouse Gas
Inventories (TFI)
12. The basis in Science
Data and Scenario
Support for Impacts
and Climate Analysis
(TGICA)
13. The basis in Science
The IPCC also produces
Special Reports
Methodology Reports
Technical Papers
Supporting Material
14. The basis in Science
Nobel Peace Prize
2007
Al Gore and IPCC
16. THE SCIENCE
DIRECT OBSERVATIONS OF RECENT
CLIMATE CHANGE
Global average air temperature
• Updated 100-year linear trend of 0.74 [0.56 to
0.92] o
C for 1906-2005
• Larger than corresponding trend of 0.6 [0.4 to
0.8] o
C for 1901-2000 given in TAR
• Average ocean temperature increased to
depths of at least 3000 m – ocean has
absorbed 80% of heat added
• seawater expansion and SLR
17. THE SCIENCE
DIRECT OBSERVATIONS OF RECENT
CLIMATE CHANGE
At continental, regional, and ocean basin
scales, numerous long-term changes in
climate have been observed. These include:
– Changes in Arctic temperatures and ice
– Widespread changes in precipitation
amounts, ocean salinity, wind patterns
– Aspects of extreme weather including
droughts, heavy precipitation, heat waves
and the intensity of tropical cyclones
18. Global mean temperatures are rising faster with time
100 0.074±0.018
50 0.128±0.026
Warmest 12 years:
1998,2005,2003,2002,2004,2006,
2001,1997,1995,1999,1990,2000
Period Rate
Years °/decade
20. Changes in Precipitation
Increased Drought
• Significantly increased precipitation in eastern
parts of North and South America, northern
Europe and northern and central Asia.
• The frequency of heavy precipitation events
has increased over most land areas - consistent
with warming and increases of atmospheric
water vapour
• Drying in the Sahel, the Mediterranean,
southern Africa and parts of southern Asia.
• More intense and longer droughts observed
since the 1970s, particularly in the tropics and
subtropics.
21. Other changes - Extreme Events
• Widespread changes in extreme temperatures
observed
• Cold days, cold nights and frost less frequent
• Hot days, hot nights, and heat waves more
frequent
• Observational evidence for an increase of
intense tropical cyclone activity in the North
Atlantic since about 1970, correlated with
increases of tropical sea surface temperatures
22. The most important
spatial pattern (top) of
the monthly Palmer
Drought Severity
Index (PDSI) for 1900
to 2002.
The time series
(below) accounts for
most of the trend in
PDSI.
Mainly decrease in rain
over land in tropics and
subtropics, but enhanced
by increased atmospheric
demand with warming
Drought is increasing in most places
23. Warm nights are increasing;
cold nights decreasing
Frequency of occurrence of cold or warm temperatures for 202 global
stations for 3 time periods:
1901 to 1950 (black), 1951 to 1978 (blue) and 1979 to 2003 (red)
⇐fewer more⇒ ⇐fewer more⇒
1979-2003
1951-1978
1901-1950
1979-2003
1951-1978
1901-1950
24. Smoothed annual anomalies for precipitation (%) over land from
1900 to 2005; other regions are dominated by variability.
Land precipitation is changing significantly over broad areas
Increases
Decreases
26. THE SCIENCE
Greenhouse Gas
Gases that trap heat in the atmosphere
are often called greenhouse gases.
• Carbon Dioxide (CO2)
• Methane (CH4)
• Nitrous Oxide (N2O)
• Fluorinated Gases
27. The atmospheric concentration of CO2 and CH4 in 2005
exceeds by far the natural range of the last 650,000 years
CO2
CH4
28.
29. • Net CO2 emissions = 7.9 GtC/yr
• Net CO2 intake capacity = 3.1 GtC/yr
• Excess CO2 emissions = 4.8 GtC/yr, 55% more than intake capacity
53. Coastal Zones
Vulnerable areas along the Indian
Coast due to SLR
•Simulation models show an increase in frequencies of
tropical cyclones in the Bay of Bengal particularly
intense events are projected during the post-monsoon
period
•Sea level rise is projected to displace populations in
coastal zones, increase flooding in low-lying coastal
areas, loss of crop yields from inundation and
salinization.
7500 km coast line
54.
55. •Decrease in yield of crops as temperature increases in
different parts of India - For example a a 2°C increase in
mean air temperature, rice yields could decrease by about
0.75 ton/hectare in the high yield areas and by about 0.06
ton/hectare in the low yield coastal regions.
•Major impacts of climate change will be on rain fed crops
(other than rice and wheat), which account for nearly 60%
of cropland area. In India poorest farmers practice rain fed
agriculture.
•The loss in farm-level net revenue will range between 9
and 25% for a temperature rise of 2-3.5°C.
Agriculture
56. Health
Malaria is likely to persist in many states and new regions at
hogher latitudes may become malaria-prone
The duration of the malaria transmission windows is likely to
widen in northern and western states and shorten in
southern states.
Endemic
regions of
malaria
Regions likely to
be affected by
malaria in 2050s
59. Modern Environment Movement
Our Common Future
1987
sustainable development
United Nations Conference on the Human Environment in Stockholm, Sweden, in 1972United Nations Conference on the Human Environment in Stockholm, Sweden, in 1972United Nations Conference on the Human Environment in Stockholm, Sweden, in 1972
