Global Climate Change Scenario

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Global Climate Change Scenario
SAARC Training Program on Climate Change
Adaptation and Disaster Risk Reduction in South
Asia
Dr. A.K.M. Saiful Islam
Associate Professor, IWFM Coordinator , Climate
Change Study Cell
Bangladesh University of Engineering and
Technology
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Outline

• Introduction to Climatic System
• Green House Effect and Global Warming
• Status of Global Climate Change
• Climate Change Predictions
• Climate Change Scenarios
• Climate Change Scenarios for Bangladesh
• Overview of the Impact of Climate Change

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Climate Systems

• The complicated system consisting of various
  components, including the dynamics and
  composition of the atmosphere, the ocean, the ice
  and snow cover, the land surface and its
  features, the many mutual interactions between
  them, and the large variety of physical, chemical
  and biological processes taking place in and
  among these components.
• Climate refers to the state of the climate
  system as a whole, including a statistical
  description of its variations.
• Atmosphere
• 78 nitrogen, 21 oxygen, and 1 other gases.
• Carbon dioxide accounts for just 0.03 - 0.04.
• Water vapor 0 to 2

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Components of Climate System
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Green house gases

• CO2 and some other minor gases
• Absorb some of the thermal radiation leaving the
  surface of the earth.
• Emit radiation from much higher and colder levels
  out to space.
• These radiatively active gases are known as
  greenhouse gases.
• They act as a partial blanket for the thermal
  radiation from the surface which enables it to be
  substantially warmer than it would otherwise be,
  analogous to the effect of a greenhouse.

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Green house effect
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Human induced climate variation

• Perturbations of the atmospheric composition
  the enhanced greenhouse effect
• Effect of aerosols
• direct effect (scattering of incoming solar
  radiation)
• indirect effect (affecting the radiative
  properties of clouds)
• Land-use change (agriculture, deforestation,
  reforestation, afforestation, urbanisation,
  traffic, )

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Sector wise Green house gas emission
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Increasing trends of CO2
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Human induced changes of green house gases
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Global temperature and Greenhouse gases
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Temperature variation past 1,000 years
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Increase of Temperature past 140 year
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Surface Air temperature (1960-1990)
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Ice melting

• Images gathered from the Defense Meteorological
  Satellite Program of NASA show the minimum Arctic
  sea ice concentration 1979 (left) and 2003
  (right).

1979
2003
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Cracks in Ice bars
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Trends of Sea Surface temperature
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Sea Level Rise (1980-2000)

• 20 cm rise of Global Sea Level in last century.
• Prediction of another 80 cm rise by 2100.

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Trends of Precipitations
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Climate Models to predict climate change

• Climate models are computer-based simulations
  that use mathematical formulas to re-create the
  chemical and physical processes that drive
  Earths climate. 
• To run a model, scientists divide the planet
  into a 3-dimensional grid, apply the basic
  equations, and evaluate the results.
• Atmospheric models calculate winds, heat
  transfer, radiation, relative humidity, and
  surface hydrology within each grid and evaluate
  interactions with neighboring points.
• Climate models use quantitative methods to
  simulate the interactions of the atmosphere,
  oceans, land surface, and ice.

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GCM typical horizontal resolution of between 250
and 600 km, 10 to 20 vertical layers in the
atmosphere and sometimes as many as 30 layers in
the oceans.
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Special Report on Emissions Scenarios (SRES)

• The Special Report on Emissions Scenarios (SRES)
  was a report prepared by the Intergovernmental
  Panel on Climate Change (IPCC) for the Third
  Assessment Report (TAR) in 2001, on future
  emission scenarios to be used for driving global
  circulation models to develop climate change
  scenarios.
• It was used to replace the IS92 scenarios used
  for the IPCC Second Assessment Report of 1995.
  The SRES Scenarios were also used for the Fourth
  Assessment Report (AR4) in 2007.

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SERS Emission Scenarios

• A1 - a future world of very rapid economic
  growth, global population that peaks in
  mid-century and declines thereafter, and the
  rapid introduction of new and more efficient
  technologies. Three sub groups fossil intensive
  (A1FI), non-fossil energy sources (A1T), or a
  balance across all sources (A1B).
• A2 - A very heterogeneous world. The underlying
  theme is that of strengthening regional cultural
  identities, with an emphasis on family values and
  local traditions, high population growth, and
  less concern for rapid economic development.
• B1 - a convergent world with the same global
  population, that peaks in mid-century and
  declines thereafter, as in the A1 storyline.
• B2 - a world in which the emphasis is on local
  solutions to economic, social and environmental
  sustainability.

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Impact of the Changes of Green house gases

• Summary of changes in the global environment by
  the 2050s and 2080s for the four scenarios
  expressed as changes from the 1961-90 average.
  The current (1999) CO2 concentration is about
  370ppmv. The effects of aerosols on climate are
  not considered. (ppmv parts per million by
  volume)

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Temperature increase versus SRES
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Predicted changes of Temperature
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Projected changes in annual temperatures for the
2050s
BW 11

• The projected change in annual temperatures for
  the 2050s compared with the present day, when the
  climate model is driven with an increase in
  greenhouse gas concentrations equivalent to about
  1 increase per year in CO2

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Sea Level Rise
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Climatic Condition of Bangladesh

• Mean daily temperature of Bangladesh has
  increased with a rate of 1.03 0C per 100 years

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Change of mean temperature (0C/year)
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Predicting Rainfall
Output of PRECIS model using SRES A2 scenario
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Predicting Maximum Temperature
Output of PRECIS model using SRES A2 scenario
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Predicting Minimum Temperature
Output of PRECIS model using SRES A2 scenario
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Predictions over Bangladesh
http//teacher.buet.ac.bd/akmsaifulislam/climate/i
ndex.htm
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Overview of the Impacts of climate change

• Human Health impacts
• Ecosystem Impacts
• Agriculture Impacts
• Water Resources Impacts
• Market Impacts

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Human Health impacts

• Expansion of the areas of potential transmission
  of malaria and dengue fever (medium-to-high
  confidence) roughly 300 million more people at
  risk of malaria
• Increased heat-related deaths and illness,
  affecting particularly the elderly, sick, and
  those without access to air conditioning
• Increased risks to human life, risk of infectious
  disease epidemics and many other health risks
  where floods, droughts or storms increase in
  frequency and/or intensity
• Decreased winter deaths in some temperate regions

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Ecosystem Impacts

• Coral death from exposure to 3-4 ºC higher
  seasonal maximum sea-surface temperatures for 6
  months or more
• Substantial reduction in glacier and ice-cap
  volume tropical glaciers particularly vulnerable
  to elimination
• Loss of unique vegetation systems and their
  endemic species (e.g. vegetation of Cape region
  of South Africa and some cloud forests)
• Extensive reduction in Arctic summer sea-ice
  extent with benefits for shipping but adverse
  effects on sea-ice dependent animals (e.g. polar
  bears, seals, walrus)
• Coastal wetland loss from sea level rise (up to
  10 globally for 20 cm rise, higher percentages
  in some areas)
• Increased disturbances of ecosystems by fire and
  insect pests
• Increase net primary productivity of many mid-
  and high-latitude forests
• Extinction of some critically-endangered and
  endangered species

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Agriculture Impacts

• General decrease in cereal crop yields in
  mid-latitudes
• Decreased crop yields in areas of increased
  drought
• Food prices increase relative to projections that
  exclude climate change
• Decreased cereal crop yields in most tropical and
  subtropical regions
• Increased heat stress in livestock and crop
  damage from heat waves
• Decreased frost damage for some crops

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Water Resources Impacts

• Decreased water quantity and quality in some
  areas of increased drought
• Increased flood damage due to more intense
  precipitation events
• Decreased water supply in many water stressed
  countries (half-billion people in central Asia,
  southern Africa, and countries surrounding the
  Mediterranean affected)
• Increased water supply in some other water
  stressed countries (e.g. parts of Asia)

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Market Impacts

• Net market sector losses most regions and for
  global aggregate
• Increased insurance prices and reduced insurance
  availability in response to increased frequency
  and intensity of some extreme climate events
• Decreased energy demand for heating buildings in
  winter and increased energy demand for cooling
  buildings in summer
• Net market sector losses in many developing
  countries

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Emission of CO2 -gtwho is responsible?

• Per capita emissions of CO2 is less than 0.2 ton
  annually in Bangladesh, compared to 1.6 tons in
  the developing countries

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Thank you