Why all the Fuss?
Kartikeya V. Sarabhai
We have mangoes in
summer and undhyu in winter. We are used to fluctuating temperatures and
the changes it brings about. We know that the cold wave and shivers in
Ahmedabad today will in a couple of months, give way to hot steamy days.
10ºC in January will be nearly 46ºC by May, a difference of over 35ºC.
But why talk of months, even during a single day the temperatures vary
by 8 - 10ºC. So when the world talks of climate change and global
warming and warns that we could see average temperatures rising by 1.8 -
4ºC during 21st century, why is there a fuss?
To understand this, it
is important to know the distinction between weather and climate.
Weather is a set of phenomena and conditions of the atmosphere at a
given time and a given place which often results from temperature
differences from one place to another. Common weather phenomena include
wind, cloud cover, rain, snow, fog, thunder and lightning, dust storms,
cyclones etc. Weather refers to local conditions of the atmosphere over
a short time span (days or weeks). Climate, in turn, is the average and
variations of weather in a region over longer periods from a minimum of
30 years up to millions of year. Earth has undergone periodic climate
shifts in past but the recent rise in global temperature does not follow
this cycle.
Dr. R.K. Pachauri,
chairman of the Intergovernmental Panel on Climate Change, spoke on
climate change during the recent 4th International Conference
on Environmental Education at Centre for Environment Education,
Ahmedabad. He stressed that the warming of the last half century is
unusual in previous 1,300 years (see figure ‘Global Mean Temperature)
and that during the 20th century glaciers and ice caps have
experienced widespread mass losses which have very likely raised the sea
level. Increase of 0.68ºC per century, pronounced warming in post
monsoon and winter, increase in extreme rains in the north-west during
monsoon and lower number of rainy days along east coast are some of the
observed impacts of climate change in India.
The projected climate change will further increase
the air and ocean temperature which in turn will affect the water cycle.
Only 3% of Earth’s total water is fresh water and any shift and
reduction in rainfall and melting of glaciers will increase the drinking
water scarcity. We are also likely to witness more droughts and high
rainfall events, higher cyclonic activity, shifts of forest types, loss
of biodiversity, reduction in crop production, flooding of coastal areas
and river banks. These changes will also increase vector-borne diseases,
affect human health, human settlement, industries and future
development. Scarce resources and extreme weather events might as well
lead to crisis, threatening human security in India and the world.
It is evident that
developing countries, including India, will be more affected by climate
change because they depend more on climate-sensitive sectors like rain
fed agriculture, forestry or fishing. Also, arid and semi-arid areas are
particularly vulnerable to adverse effects of climate change. For India,
climate change mainly implies water scarcity due to the melting of the
Himalayan glaciers and shifting monsoon patterns as well as sea level
rise. Gujarat, a semi-arid zone, having the longest coastline of any
state in India with fragile ecosystems like desert, wetlands and coral
reefs and a unique biodiversity is highly susceptible to climate
change. 63% of its population depends on agriculture and related
sectors and as a result we are very vulnerable to climate change.
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