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Strong Winds and
Tornadoes:
The
Intergovernmental Panel on Climate Change (IPCC) scientists, through their
report released on February 2, 2007, said temperatures were probably going
to increase by 1.8-4C (3.2-7.2F) by the end of the century. Global
temperatures have been on the increase since 1750, following the
industrial revolution of the developed world, fuelling the suspicion that
the earth warming is not unrelated to human activities. Temperature
increases cause earth warming and are believed to contribute to some of
the strong winds and tornadoes we have witnessed in recent times.
Glacier
Melting/declining snow cover:
With increase
temperature, the arctic and semi-arctic regions are gradually loosing
their glacier and snow covers. Several locations on the Earth previously
covered with snow decades ago are loosing their snow cover to green
grasses.
Glacier melting
has significant effect on the human and animal lives. It has been stated
that over 1.5 million of the world population (mostly in South America,
China and India) depend on glacier runoff for drinking water supply. As
glaciers turn into lakes and flowing rivers, the regions that have
depended on glacier runoff for drinking water source will be greatly
impacted with water shortage. This has a lot of implications for human and
animal health.
Rising river
flow and sea levels:
With the melting
of glacier and snow cover comes the rising of river flow and sea levels.
The IPCC report projected that sea levels were most likely to rise
by 28-43cm, and global warming was likely to influence the intensity of
tropical storms.
Rising river
flow and water levels has implications for the quality and quantity of
water available for drinking and other purposes. More flooding and
flooding epidemics are expected with increased water levels. Increased
volumes of stormwater and sewage runoff are anticipated and could impact
existing wastewater treatment facilities in most cities of the World.
Flood Disasters
of the magnitude of Tsunami are likely to be on the increase as the river
flow and water levels increase.
Decrease in
water levels in ponds, lakes and other water bodies:
In temperate
climates, water storage capabilities will be affected by rising
temperature. Waters stored in Lakes, Dams and other storage media will be
lost to global warming reducing drinking water supplies to those regions.
Increasing
precipitation:
With global
warming comes high moisture evaporation and resulting increased
precipitation (i.e.
rainfall) in temperate regions. This is capable of causing flood
disasters and related problems.
It has been reported that there
has been a 5-10% increase in
precipitation
over the past century. Also,
in the last ten years,
floods have caused almost US$300
billion of damage, that’s three to six times the amount of damage caused
by floods in previous decades.
Timing of lake
and river freeze-up/break-up:
In the arctic
regions of the World, the timing of the lake and river freeze-up and
break-up is extremely crucial for basically all activities. Construction
activities, transportation activities, recreation activities and so on are
planned based on the freeze-up/break-up timing. More uncertainties about
this timing are expected with global warming. Huge
industrial establishments such as multi-billion dollar mining operations
in the arctic receive their
annual
supplies only
during winter times using the winter roads.
Global warming reduces the
length of the period of the year ice roads can remain frozen and passable.
This consequently affects operations in those mines except alternative
means of transportation is arranged.
Thawing
of Permafrost
Permafrost is soil or rock that
remains at or below 0°C or 32°F for two or more
years. Most permafrost is located in high latitudes (e.g. North and South
poles). The upper part of the permafrost is called the Active Layer
because it seasonally thaws during the summer months and freezes during
the winter months.
In regions with permafrost, the only concern with building
structures on permafrost used to be permafrost melting under the weight of
the building. The heat melts the permafrost, increases the depth of the
active layer and may cause the structure on top of the permafrost to sink.
Several solutions have been devised for this problem. They include:
building on piles (wood or steel types) driven down into the permafrost,
using thick gravel pads or using anhydrous ammonia heat pipes. The threat
of global warming introduces a different and more challenging concern.
In areas where permafrost is thinner and ground
temperatures are warmer than –20C, there is the potential for
significant loss of permafrost over the long term while in areas of
thicker permafrost where ground temperatures are at or below –50C,
global warming will cause a thicker active layer and a gradual overall
thinning of permafrost. As permafrost warms, groundwater storage capacity
will increase. Increased water in the active layer may result in other
impacts such as increased frost heave. Other effects are icing activity
particularly during spring break-up, impact on surface water quality, fish
and aquatic life, due to increased dissolved solids from the interaction
between shallow groundwater and surface water.
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