The Lucknow Sentinel, 1991-03-06, Page 43s
0
Green./1.
will w.T.•rm
Sio°ailZi
Average wintertemPeronnes irr°
the ChArctic tic could increase,
8 to 10 degrees Celsius if global
warming scenarios prove accurate,
says an Environment Canada iEnz„
fist.
The change could be a boon to
tourism and industry, but a threat to
Native people and wildlife, the
researcher adds.
The Combination of melting . ice
and snow as well as Arctic tem-
perature inversions could result iii a
dramatically enhanced `greenhouse
effect', says Dr. Barrie Maxw-el1,
head of Arctic Cliattrnatclogy at the
Atmospheric Environment Service.
Scientists are predicting signifi-
cant climate change in the next
centurybecause of alterations in the
composition of the atmosphere.
Since the ,rid -1800s, the propor-
tions
ropostions of carbon dioxide, methane,
and other heat -trapping `greenhouse
gases' haverisen steadily, as people
burned more fossil ` fuels : and
brought -more land under cultiva-
tion.
Con pt -bit climate models
indicate that if these trends con-
tinue, the average global tempera-
ture may increase by 1.5 to . 4.5
degrees Celsius over the next five
Conditions 'Milt* to the Arctic
suggest its winter temperatures`will.
increase even more, says Maxwell.
"Right now, solar radiation tends to.
be reflected by snow and ice before
it can warm the ground. ' As global
temperatures increase however
snow will begin to melt and a feed-
back situation may develop," .he
says.
"As snow and ice disappear, more
energy will be absorbed (by the
ground). As more is absorbed, more
melting. will occur.
Temperature inversions may
enhance this effect, he adds. In
winter, the Arctic, air ass is char-
acterized by a narrow layer of
warm air close to the earth's sur-
face, which prevents heat from
escaping into the outer atmosphere.
In other words, energy radiated by
the earth remains near ground level.,
Maxwell says these processes will
probably have a profound impact on
the lives of northeners. People who
earn their living from tourism
should benefit the most, as warmer
temperatures translate into shorter
winters and'longer summers. Higher
temperatures could cause a north-
ward migration of fish, creating a
fisheries industry. And melting sea
ice may encourage an increase in
shipping and oil exploration.
For Natives who hunt and trap,
however, die future looks bleaker.
How many litres of maple
sap must be collected to
produce a single litre of
maple syrup: 30,40, or 50?
Forty litres. •
Again, ruihual mig ttion Patterns
s
wail likely shift north. "On the
mainland. this WI a 00b4e1119 bat
in the Arctic islands It may ,'
Maxwell says,. "For eXO*Pleclf sea
,„x l is ► d::� 's' a co
v'c
snowfall one> year, we might .see
whole populations of caribou
traneti on islands Mat, can't support
them.'
.
The Greenhouse effect:, 1, solar
energy Wert; atmosphere; 2,.
solar energyis absorbed by the
earth. then reradiated .,flack to
spe;.3. greenhouse gases absorb
the heat and reradite it back to
earth, acting like. an .insulating
blanket; 4. in bigb concentrationS,.
greehouse gases trap _ much
reradiated heat, 'causing global`
warming. (Dr. Barrie . Maxwell,
AES)
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