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Global warming humanforced rapid global climate change a social justice issue

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The first image shows the minimum sea ice concentration for the year 1979, and ... Also, such a slug of cold, fresh water disrupts ocean currents and the ... – PowerPoint PPT presentation

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Title: Global warming humanforced rapid global climate change a social justice issue


1
  • Global warming (human-forced rapid global climate
    change) a social justice issue

Dr Brendan Mackey, Reader School of Resources,
Environment and Society/Faculty of Science Email
brendan.mackey_at_anu.edu.au
2
Human-forced rapid climate change is real and is
happening. The planet is and will continue to get
warmer and global climate systems will change
rapidly over the coming years, decades and
centuries.
There is scientific uncertainty about whether the
planet will overall get wetter or drier, which
regions will get wetter or drier, and when these
changes will occur.
  • There is less scientific uncertainty about
    changes in sea level
  • Thermal expansion of water
  • Ice melt
  • Lag affect

3
The first image shows the minimum sea ice
concentration for the year 1979, and the second
image shows the minimum sea ice concentration in
2003. Images NASA
Source http//www.smh.com.au/articles/2003/10/24/
1066631611744.html
4
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7
If greenhouse gas concentrations were stabilised
(even at present levels), sea level would
nonetheless continue to rise for hundreds of
years. After 500 years, sea level rise from
thermal expansion may have reached only half of
its eventual level, which models suggest may lie
within a range of 0.5 to 2.0 m and 1 to 4 m for
CO2 levels of twice and four times preindustrial,
respectively. Ice sheets will continue to react
to climatic change during the next several
thousand years, even if the climate is
stabilised. Models project that a local annual
average warming of larger than 3C, sustained for
millennia, would lead to virtually a complete
melting of the Greenland ice sheet. Projected
temperatures over Greenland are generally greater
than globally averaged temperatures by a factor
of 1.2 to 3.1 for the range of models.

8
See http//www.gfdl.noaa.gov/tk/climate_dynamics
/fig4.gif
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10
More substantial changes in sea level are
possible. Some scientists believe that the West
Antarctic Ice Sheet could slide into the ocean
after a sustained warming.
Evidence in the geological record points to this
happening in the past. As ice sheet starts to
melt, a layer of water builds up between the ice
and land mass, causing the ice sheet to rapidly
slide off.
A large ice sheet dropping from land into the
adjoining sea will cause a massive and sudden
increase in sea level.
11
  • Low-lying coastal countries are threatened by
    rising sea level. A one meter rise in sea level
    would
  • Inundate half of Bangladesh's rice land.
    Bangladeshis would be forced to
  • migrate by the millions.
  • Other rice growing lowlands which would be
    flooded include those of
  • Viet Nam, China, India and Thailand. Millions
    of climate refugees could be
  • created by sea level rise in the Philippines
    and Indonesia.
  • In Egypt, a 1m sea level rise will affect 6
    million people with 12-15 of
  • agricultural land lost,
  • Around 72 million in China are estimated to be
    affected by a 1m rise.

12
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13
The freshwater resources of small islands are
particularly vulnerable to the effects of global
warming because they exist only as a thin,
buoyant lens floating on a larger subsurface
reservoir of saltwater. Such islands will run out
of clean water before they flood, due to salt
water intrusion from rising sea levels, affect
1 million people.
Source http//portal.unesco.org/en/ev.php-URL_ID
13604URL_DODO_PRINTPAGEURL_SECTION201.html
14
Sea-level rise leads to increased coastal
flooding through direct inundation and an
increase in the base for storm surges, allowing
flooding of larger areas and higher elevations.
One study, for example, estimated that a rise in
sea level of 30 to 90 cm would increase the size
of the 100-year floodplain in the United States
by 10,000 to 20,000 km2 (FEMA, 1991). Put
differently, storms of a given magnitude will
have a shorter return interval. High tide peaks,
for example, that occur once every one hundred
years on average may occur every ten years,
making now rare events more common. In some
areas, flooding could be further exacerbated by
an increase in extreme precipitation events
resulting from an intensification of the
hydrological cycle. Heavy precipitation
associated with coastal storms causes increased
runoff and river surges that intensify the
effects of storm surges from the sea. Levees
and seawalls currently protect many coastal
areas, but these structures have been designed
for current sea level and may be overtopped in
the future or undermined by increased erosion.
15
Carbon dioxide emissions per capita 2002 (tonnes)
16
The ultimate objective of this convention
and any related legal instruments is to
achievestabilization of greenhouse gas
concentrations in the atmosphere at a level that
would prevent dangerous anthropogenic
interference with the climate system. Such a
level should be achieved with a timeframe
sufficient toensure that food production is not
threatened and to enable economic development to
proceed in a sustainable manner. The
developed country parties commit themselves
specifically to adopt national policies and
take corresponding measures on the mitigation of
climate change, by limiting its anthropogenic
emissions of greenhouse gases and protecting and
enhancing its greenhouse gas sinks and
reservoirs. These policies and measures will
demonstrate that developed countries are taking
the lead in modifying longer term-term trends in
anthropogenic emissions with the objective of the
Convention The Parties should protect the
climate system for the benefit of present and
future generations of humankind, on the basis of
equity and in accordance with their common but
differentiated responsibilities and respective
capabilities. Accordingly, the developed country
parties should take the lead role in combating
climate change and the adverse effects
thereof. The parties should take precautionary
measures to anticipate, prevent or minimize the
causes of climate change and mitigate its adverse
effects. Where there are threats of serious or
irreversible damage. Lack of full scientific
certainty should not be used as a reason for
postponing such measures 
17
  • The ethical commitments in the UNFCC may not be
    enforceable but they are legally binding on all
    governments, including the Australian Government.
    We are legally and morally bound to act.
  • The Australian government should ratify the
    Kyoto Protocol and help negotiate a new
    post-Kyoto Protocol based on principles of
    justice and equity to advance the aims of the
    UNFCCC.
  • An example of a just and equitable approach to a
    protocol is the Contraction and Convergence
    approach whereby nations (1) agree on a safe
    atmospheric concentration of CO2 emissions
    contraction and (2) commit to reduce total
    emissions to achieve this safe concentration
    through a universal per capita emission
    allocation that is differentially reached at a
    specified time in the future convergence.

18
  • Ultimately we have no choice. The longer we wait
    to respond, the more the worlds vulnerable will
    suffer, and the more costly will be the solutions.
  • Australias governments need to develop and
    promote policies and programmes that will
    dramatically reduce our emissions of greenhouse
    gases.
  • The Australian government and people should
    adopt a good neighbour approach and begin now
    to help our friends in the Oceania region who are
    suffering and will continue to suffer from sea
    level rises and other consequences of rapid
    global climate change.
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