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For many environmentalists, the world seems to be getting warmer. As
the nearest country of South Polar Region, New Zealand has maintained an
upward trend in its average temperature in the past few years. However, the
temperature in New Zealand will go up 4oC in the next century while the
polar region will go up more than 6oC. The different pictures of
temperature stem from its surrounding ocean which acts like the air
conditioner. Thus New Zealand is comparatively fortunate.
Scientifically speaking, this temperature phenomenon in New Zealand
originated from what researchers call “SAM” (Southern Annular Mode), which
refers to the wind belt that circles the Southern Oceans including New
Zealand and Antarctica. Yet recent work has revealed that changes in SAM in
New Zealand have resulted in a weakening of moisture during the summer, and
more rainfall in other seasons. A bigger problem may turn out to be heavier
droughts for agricultural activities because of more water loss from soil,
resulting in poorer harvest before winter when the rainfall arrive too late
to rescue.
Among all the calamities posed be drought, moisture deficit ranks the
first. Moisture deficit is the gap between the water plants need during the
growing season and the water the earth can offer. Measures of moisture
deficit were at their highest since the 1970s in New Zealand. Meanwhile,
ecological analyses clearly show moisture deficit is imposed at different
growth stage of crops. If moisture deficit occurs around a crucial growth
stage, it will cause about 22% reduction in grain yield as opposed to
moisture deficit at vegetative phase.
Global warming is not only affecting agriculture production. When
scientists say the country’s snow pack and glaciers are melting at an
alarming rate due to global warming, the climate is putting another strain
on the local places. For example, when the development of global warming is
accompanied by the falling snow line, the local skiing industry comes into a
crisis. The snow line may move up as the temperature goes up, and then the
snow at the bottom will melt earlier. Fortunately, it is going to be
favorable for the local skiing industry to tide over tough periods since
the quantities of snowfall in some areas are more likely to increase.
What is the reaction of glacier region? The climate change can be
reflected in the glacier region in southern New Zealand or land covered by
ice and snow. The reaction of a glacier to a climatic change involves a
complex chain of processes. Over time periods of years to several decades,
cumulative changes in mass balance cause volume and thickness changes,
which will affect the flow of ice via altered internal deformation and
basal sliding. This dynamic reaction finally leads to glacier length
changes, the advance or retreat of glacier tongues. Undoubtedly, glacier
mass balance is a more direct signal of annual atmospheric conditions.
The latest research result of National Institute of Water and
Atmospheric (NIWA) Research shows that glaciers line keeps moving up
because of the impacts of global warming. Further losses of ice can be
reflected in Mt. Cook Region. By 1996, a 14 km long sector of the glacier
had melted down forming a melt lake (Hooker Lake) with a volume. Melting of
the glacier front at a rate of 40 m/yr will cause the glacier to retreat at
a rather uniform rate. Therefore, the lake will continue to grow until it
reaches the glacier bed.
A direct result of the melting glaciers is the change of high tides
the serves the main factor for sea level rise. The trend of sea level rise
will bring a threat to the groundwater system for its hyper-saline
groundwater and then pose a possibility to decrease the agricultural
production. Many experts believe that the best way to counter this trend is
to give a longer-term view of sea level change in New Zealand. Indeed, the
coastal boundaries need to be upgraded and redefined.
There is no doubt that global warming has affected New Zealand in
many aspects. The emphasis on the global warming should be based on the
joints efforts of local people and experts who conquer the tough period.
For instance, farmers are taking a long term, multi-generational approach
to adjust the breeds and species according to the temperature. Agriculturists
also find ways to tackle the problems that may bring to the soil. In broad
terms, going forward, the systemic resilience that’s been going on a long
time in the ecosystem will continue.
How about animals’ reaction? Experts have surprisingly realized that
animals have unconventional adaptation to global warming. A study has
looked at sea turtles on a few northern beaches in New Zealand and it is
very interesting to find that sea turtles can become male or female
according to the temperature. Further researches will try to find out how
rising temperatures would affect the ratio of sex reversal in their growth.
Clearly, the temperature of the nest plays a vital role in the sexes of the
baby turtles.
Tackling the problems of global warming is never easy in New Zealand,
because records show the slow process of global warming may have a
different impact on various regions. For New Zealand, the emission of
carbon dioxide only accounts for 0.5% of the world’s total, which has met
the governmental standard.
However, New Zealand’s effort counts only a tip of the iceberg. So
far, global warming has been a world issue that still hangs in an ambiguous
future.
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