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Impacts of climate change
 Climate
change is a threat to mankind! Since the end of the 19th century the
earth's average surface temperature has increased by 0.3-0.6 °C.
Over the last 40 years, the rise has been 0.2-0.3 °C. Recent years
have been the warmest since 1860, the year when regular instrumental
records became available.
Some
important aspects of our lives can be affected through changes in
weather patterns and some of these are discussed here.
Agriculture
The steadily-increasing human population has led to a rise in the
demand for food. As more land comes under agricultural cultivation
there will be more pressure on natural ecosystems. Climate change
will affect agricultural yield directly because of alterations in
temperature and rainfall, and indirectly through changes in soil quality,
pests, and diseases. In particular, the yield of cereals is expected
to decline in India, Africa, and the Middle East. As the temperature
rises conditions will become more favourable for pests such as grasshoppers
to complete a number of reproduction cycles thereby increasing their
population. In the higher latitudes (in the northern countries) agriculture
will benefit with the rise in temperature as the winter season will
be shorter and the growing seasons longer. This will also mean that
pests that will move towards the higher latitudes as the temperatures
rise. Extreme weather conditions such as high temperature, heavy rainfall,
floods, droughts, etc. will also affect crop production.
Weather
A warmer climate will change rainfall and snowfall patterns, lead
to increased droughts and floods, cause melting of glaciers and polar
ice sheets, and result in accelerated sea- level rise. Rising warmth
will lead to an increase in the level of evaporation of surface water;
the air will also expand and this will increase its capacity to hold
moisture. This, in turn, will affect water resources, forests, and
other natural ecological systems, agriculture, power generation, infrastructure,
tourism, and human health. An increase in the number of cyclones and
hurricanes over the last few years has been attributed to changes
in temperature.
Sea
level rise
Coastal areas and small islands are among the most densely-populated
parts of the world. They are also the most threatened because of rises
in sea level that global warming may cause. The heating of oceans,
and melting of glaciers and polar ice sheets, is predicted to raise
the average sea level by about half a metre over the next century.
Sea-level rise could have a number of physical impacts on coastal
areas, including loss of land due to inundation and erosion, increased
flooding, and salt-water intrusion. These could adversely affect coastal
agriculture, tourism, freshwater resources, fisheries and aquaculture,
human settlements, and health. Rising sea levels threaten the survival
of many low-lying island nations, such as the Maldives and Marshall
Islands.
There could be large decreases in the availability of water in many
rivers because of rainfall and snow. The volume in others would increase
due to glaciers melting, for example, the rivers originating in the
Himalayas. Shifts in water availability could also affect hydropower
generation, and industries such as paper, pharmaceutical, and chemical
manufacturing, that use large quantities of water. Buildings and other
infrastructure would be vulnerable to any increase in the frequency
of storms and other extreme events, which could also disrupt transport
routes.
Health
Global warming will directly affect human health by increasing cases
of heat stress.
Forests
and wildlife
Ecosystems sustain the earth's entire storehouse of species and genetic
diversity. Plants and animals in the natural environment are very
sensitive to changes in climate. The ecosystems that are most likely
to be affected by this change are the ones in the higher latitudes,
the tundra forests. Polar regions will feel the impact of warming
more than others. Interiors of continents will experience more warming
than the coastal regions.
National parks are supposed to provide a sanctuary to wildlife from
the ravages of humankind on nature. But no park boundary or conservation
law can protect an ecosystem from climate change. A recent report
by the WWF (The World Wide Fund for Nature) states that this invisible
killer has entered the most cherished natural areas. The giant pandas
of Wolong in China, the grizzly bears of America's Yellowstone National
Park, and the tigers in Kanha National Park in India are some of the
animals at risk from global warming. Mountain parks have been identified
as being especially at risk from the environmental destruction caused
by climate change. Species that live in the higher alpine zones, are
forced to move higher up to find a suitable habitat thus reducing
the area in which they can live. If the rate of climate change continues
to accelerate, then the extinction of some mountain plants and animals
is certain.
Migratory birds fly from the cold northern parts of the world to the
warmer south. Factors such as the weather and food sources along the
route are very important for the successful completion of their journey.
Changes in climate may bring about a shift in their feeding points
and disruptions to their flight patterns.
Marine
life
Corals are known as the tropical forests of the oceans and sustain
diverse life forms.
As
ocean waters in the tropics become warmer, the damage to coral reefs
seems to be increasing. These corals are very sensitive to changes
in water temperature, which causes bleaching. Large stretches of the
Great Barrier Reef in Australia have been damaged by bleaching.
Zooplanktons, small organisms that float on the sea surface are declining
in numbers, reducing the number of fish and sea birds that feed on
these organisms.
There
is still a great deal that we do not understand about our climate,
and about how our activities will change it. But one thing can be
said loud and clear: if we wait to get answers to these questions,
it will probably be too late!
Recent
revelations on Global warming affecting India……
A
new report by the country’s scientists has revealed that India
has almost consistently experienced more than normal annual mean
temperatures for the past 14 years, with 2006 being the warmest
recorded so far. The statistics contained in the “Annual Climate
Summary 2006”, a report produced by the National Climate Centre
Office of the Additional Director General of Meteorology (Research)
Meteorological Department, Pune revealed warming at the rate of
0.48 degrees Celsius over 100 years.The report clearly demonstrated
that since 1993, there had not been a single year when annual mean
temperature was less than the normal, remaining towards the higher
side for all the years. Records show that prior to 1991, the annual
mean temperatures were more than the normal in some years while
in others, these were less than normal. Between 1901 and 1941, annual
average temperatures were below normal for many years while since
then, years with annual average temperature anomalies towards the
higher side of the normal became more frequent. The year 2006 was
the warmest year on record since 1901, according to the report.
It was characterized by annual mean temperature over the country
as a whole being 0.59 degrees celsius above the average calculated
during 1961-1990.Minimum temperatures were more than two degrees
Celsius above normal over northern parts of the country.
Source: Times of India and Tribune- April 2007
The
report says during 2006, a number of cyclonic storms and depressions
formed over the Indian seas. Severe cold wave conditions over northern
and eastern parts of the country claimed more than 80 lives. Heat
wave events over northern and some western parts of the country
claimed close to 100 lives and as many as 1500 persons were killed
in floods during the monsoon season.
The
10 warmest years ever since the Met Department started keeping a
record of temperatures since 1901 are 2006 (0.595), 2002 (0.59),
1998 (0.50), 2004&2001 (0.47), 2003 (0.45), 1958 (0.43), 1941
(0.41), 2005(0.40), 1999 (0.39), 1953 & 2000 (0.36) and 1980
(0.34).
An
anomaly was that whereas traditionally dry areas like Saurashtra
and Kutch and West Rajasthan, besides Gujarat, Madhya Maharashtra
and Orissa, received excess rainfall, Himachal Pradesh, east and
west U.P, Bihar, Jharkhand and Assam and Meghalaya remained deficient.
But overall the country received 100% normal rainfall. During February,
northern hilly regions, Uttrakhand, Himachal and parts of Jammu
and Kashmir were abnormally warmer with maximum temperatures 6 to
8 degree above normal.
Health
impacts of climate change
Climate
change is a major problem caused by the increase of human activities
leading to several direct and indirect
impacts on health. The combustion of fossil fuels, increasing
number of industries, and large-scale deforestation are some of
the causes for the accumulation of GHGs (greenhouse gases) in the
atmosphere. According to the IPCC (Intergovernmental Panel on Climate
Change), an increase in carbon dioxide and other GHGs, like methane,
ozone, nitrous oxide, and chlorofluorocarbons, in the atmosphere
is expected to increase the average global temperature by 1.5 °
C to 4.5 ° C. This in turn will lead to changes in rainfall and
snowfall, more intense or frequent droughts, floods, and storms,
as well as a rise in sea level. These climatic changes will have
wide-ranging harmful effects including increase in heat-related
mortality, dehydration, spread of infectious diseases,
malnutrition, and damage to public health infrastructure. Thus we
should take appropriate measures to stop this
climate change.
Direct impacts
The weather has a direct impact on our health. If the overall
climate becomes warmer, there will be an increase in health problems.
It is anticipated that there will be an increase in the number of
deaths due to greater frequency and severity of heat waves and other
extreme weather events. The elderly, the very young and those suffering
from respiratory and cardiovascular disorders will probably be affected
by such weather extremes as they have lesser coping capacity. An
extreme rise in the temperature will affect people living in the
urban areas more than those in the rural areas. This is due to the
‘heat islands’ that develop here owing to the presence
of concrete constructions, paved and tarred roads. Higher temperatures
in the cities would lead to an increase in the ground-level concentration
of ozone thereby increasing air pollution problems.
Indirect impacts
Indirectly,
changes in weather pattern, can lead to ecological disturbances,
changes in food production levels, increase in the distribution
of malaria, and other vector-borne diseases. Fluctuation in the
climate especially in the temperature, precipitation, and humidity
can influence biological organisms and the processes linked to the
spread of infectious diseases.
Higher
temperature will cause the sea levels to rise that could lead to
erosion and damage to important ecosystems such as wetlands and
coral reefs. Direct impact of this rise would include deaths and
injury caused by intense flooding. Temperature rise would indirectly
result in geohydrological changes along the coastline such as saltwater
intrusion into the groundwater and the wetlands, coral reef destruction,
and damage to the drainage in the low-lying areas. Climate change
could increase air pollution levels by accelerating the atmospheric
chemical reactions that produce photochemical oxidants due to a
rise in the temperature.
Diseases
The
GHGs have been responsible for the depletion of stratospheric ozone,
which protects the earth from the harmful direct rays of the sun.
Depletion of stratospheric ozone results in higher exposure to ultra
violet rays of the sun, leading to an increase in the incidents
of skin cancer in light skinned people. It could also lead to an
increase in the number of people suffering from eye diseases such
as cataract. It is also thought to cause suppression of the immune
system.
Due
to global warming there will be an increase in the areas of habitat
of disease-spreading insects such as the mosquito, causing an increase
in the transmission of infection through these carriers.
Potential
effects on health due to sea level rise include:
 death
and injury due to flooding;
reduced
availability of fresh water due to saltwater intrusion;
contamination
of water supply through pollutants from submerged waste dumps;
change
in the distribution of disease-spreading insects;
effect
on the nutrition due to a loss in agriculture land and changes in
fish catch; and
health
impacts associated with population displacement.
Preventive measures
Reduction in the use of non-renewable
sources of energy and increased use of renewable sources will undoubtedly
decrease the emission of GHGs substantially. This decrease in the
GHGs will have a positive affect on the health and well being of
the people.
Furthermore,
switching to cleaner fuels and energy-efficient technologies will
reduce local pollutants and therefore, have an added beneficial
impact on health.
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