Climate Change

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Climate Change
A preparation Neda Salah
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Climate Change
What is climate change?
Ozone Hole
Dangerous Weather
Global Warming
How will Climate Change Effect Agriculture
Weeds, pests and diseases
The Greenhouse Effect
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What is Climate Change?

• The climate of the Earth is always changing. In
  the past it has altered as a result of natural
  causes. Nowadays, however, the term climate
  change is generally used when referring to
  changes in our climate which have been identified
  since the early part of the 1900's. The changes
  we've seen over recent years and those which are
  predicted over the next 80 years are thought to
  be mainly as a result of human behaviour rather
  than due to natural changes in the atmosphere.

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Ozone Hole
The influence of the human race on climate is
still a matter for study and speculation, but the
ability to perturb the ozone layer is an
established fact. The discovery by the British
Antarctic Survey of the Antarctic ozone hole
provided an early warning of the dangerous
thinning of the ozone layer worldwide, and
spurred international efforts to curb the
production of CFCs. If the provisions of the
Montreal Protocol on Substances that Deplete the
Ozone Layer of 1987 are revised, strengthened and
followed, there is a reasonable prospect that the
Antarctic ozone hole will permanently repair
itself, but not before the next appearance of
Halley's comet! (in the year 2061)
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Ozone Hole
British scientists began their measurements of
Antarctic ozone in 1957. The aim was to
understand the important role that ozone plays
through absorbing solar energy, in determining
the temperature profile of the stratosphere and
its wind circulation. The amount of ozone
overhead should follow a regular seasonal
pattern. The Antarctic ozone layer did so for the
first 20 years of BAS measurements, thereafter
clear deviations were observed. In every
successive spring the ozone layer was weaker than
before, and by 1984 it was clear that the
Antarctic stratosphere was changing progressively

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Ozone Hole
This phenomenon is the result of emissions,
mainly in the northern hemisphere, of
chlorofluorocarbons (CFCs) and halons. These
gases are in widespread use in refrigeration,
industrial solvents and fire control. If the
provisions of the Montreal Protocol on Substances
that Deplete the Ozone Layer of 1987 are
strengthened and followed, there is a prospect
that the Antarctic ozone hole will be repaired by
2100. Ozone is destroyed in the Antarctic spring
by chlorine formed during the sunless winter..
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Ozone Hole
T he chlorine is generated by an unusual reaction
between stable molecules, on the surface of small
stratospheric cloud particles which can only form
in the intense cold of the polar winter. The
stable molecules obtain their chlorine from CFCs
which have previously been broken up in sunlit
regions An important need is to determine the
amount and the biological effects of the
increased ultraviolet flux which is anticipated
under a thinner ozone layer.
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Water Security
Lake Water Quality      As part of the
Environmental Planning Initiatives Section, the
Lake Water Quality Program continues to promote
the stewardship and protection of the City's
lakes. Program activities are aimed at
safe-guarding the supplies of potable water,
improving the ecological health of our lakes,
maintaining healthy fisheries and assisting and
collaborating with the numerous lake stewardship
groups in our City The risk of terrorist attack
continues to impact in the most unexpected of
places. Consideration should be given to
protecting our drinking water supplies from such
risks. This would require the preparation of a
detailed strategic plan and assessment of the
current state of security in order to identify
key areas of risk. Protective solutions could
then be designed and implemented .
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Dangerous Weather
We cannot live without the suns heat and light
or the air that we breath but these givers of
life can also become dangerous killers.
Moreover they can behave even more dangerously
when they combine with that other great natural
force Water
Water security
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The Greenhouse Effect
The earth is surrounded by an atmosphere through
which solar radiation is received. The atmosphere
is not static but contains air, in constant
motion, being heated, cooled and moved, water
being added and removed along with smoke and
dust.  Only a tiny proportion of the sun's energy
reaches earth and some of this is reflected back
into space (from clouds etc.). When the radiant
energy reaches the land surface, most of it is
absorbed, being used to heat the earth, evaporate
water and to power photosynthetic processes.  
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The Greenhouse Effect
The earth also radiates energy but, because it is
less hot than the sun, this is of a longer
wavelength and is absorbed by the atmosphere. The
Earths atmosphere, thus acts like the glass of a
green house, hence the 'greenhouse effect
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The Greenhouse Effect
The greenhouse gases (dealt with in subject 3)
are those that absorb the Earths radiation and
thus contribute to the greenhouse effect, but
water is also a major absorber of energy. Where
there is an increase in the concentration of
greenhouse gases (as with CO2 due to the burning
of fossil fuels) this results in an enhanced
greenhouse effect - which is of concern as it
could lead to climate change (i.e. global
warming).
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Global Warming
Global temperatures have risen by 0.5oC over the
140 years since records began. The decade 1990 -
2000 was the warmest for 300 years and 0.5oC
warmer than the mean 1961 - 1990 climate. Warm
winters have reduced the number of frosts, and
the warmer summers have included record hot
spells  and high sunshine totals.
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How will Climate Change Effect Agriculture
Soil processes The potential for soils to support
agriculture and distribution of land use will be
influenced by changes in soil water balance
Increase in soil water deficits i.e. dry soils
become drier, therefore increased need for
irrigation but Could improve soil workability
in wetter regions and diminish poaching and
erosion risk Crops The effect of increased
temperature and CO2 levels on arable crops will
be broadly neutral
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How will Climate Change Effect Agriculture
The range of current crops will move northward
New crop varieties may need to be selected
Horticultural crops are more susceptible to
changing conditions than arable crops Field
vegetables will be particularly affected by
temperature changes Phaselous bean, onion and
sweetcorn are most likely to benefit commercially
from higher temperatures Water deficits will
directly affect fruit and vegetable production
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Grasslands and Livestock
There is unlikely to be a significant change in
suitability of livestock for UK systems Pigs and
poultry could be exposed to higher incidences of
heat stress, thus influencing productivity
Increase in disease transmission by faster
growth rates of pathogens in the environment and
more efficient and abundant vectors (such as
insects) Consequences for food quality and
storage
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Weeds, Pests and Diseases
Weeds evolve rapidly to overcome control
measures, short lived weeds and those that spread
vegetatively (creeping buttercup, couch etc)
evolve at the greatest rate Rate of evolution
will increase in hotter, drier conditions and in
'extreme years', could lead to some types of
herbicide tolerance becoming more common
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Weeds, pests and diseases
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Possible increase in the range of many native
pests, and species that at present are not
economically important may become so
Surveillance and eradication processes for other
significant pests, such as the Colarado beetle
will become increasingly important
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Prepared by

• The first Center Of Excellence students
• Nida
• Tawfeeq
• Bushra