Global warming
Global warming is simply defined as an increase in the average global
temperatures. Though, it is an environmental problem, it has serious
implications on the global economics, geopolitics, society, humanity and all
living beings. "global warming is one of the most controversial science issues
of the 21st century, challenging the very structure of our global society", says
mark. Though, there has been controversies between two schools of scientific
thought, one calling it is a myth and the other considering it is a reality, there
is sufficient evidence to support the later. Anthropogenic activities, causing
increased emissions of green house gases, are behind the global warming. It
has been established, that, if not addressed properl y and immediately, it
would have catastrophic impacts.
Global warming means earth is becoming warmer gradually. There is
increase in average global temperatures of air and oceans, accompanied by
widespread melting of glaciers and rising of sea level. The united nations
intergovernmental panel on climate change ( IPCC) in its `synthesis report on
climate change', states that there is clear evidence for a 0.6 OC rise in global
temperatures and 20cm rise in sea level during the 20th century. It predicts
that "global temperatures could rise by 1.4 to 5.8 OC and sea level could rise
by 20 to 88cm by the year 2100." majority of the scientists and research
organizations, including IPCC have reached on consensus that global
warming is caused by massive increase of g reen house gases such as carbon
dioxide (co2) in atmosphere resulting from burning of fossil fuels and
deforestation.
The temperature of earth is maintained by the balance between the heat
energy coming from the sun and the heat energy returned back to space.
Some atmospheric gases: carbon dioxide (co2), methane (ch4), nitrous oxide
(n2ox), chlorofluorocarbons (cfc) and water vapors are important to this
temperature balance. They form the green house blanket in the atmosphere.
This blanket absorbs some of the long wave radiation and re -radiate it back
to surface, which causes the atmosphere to warm up to 350c. Without these
, gases the earth's atmospheric temperature would be 15 to 200c. If more such
gases are added to the atmosphere, the earth's temperature would increase
accordingly. And these are being added enormously.
This is why the global warming is taking place with greater pace due to the
abundant increase in emissions. "the scientists community is largely
persuaded that not only is earth's climate warming, but rate of warming is
accelerating due substantially to, human activity." says dr. Terrence m. Joyce,
senior scientist and director of ocean & climate change institute.
The main evidences of global warming are three basic indicators -
temperature, precipitation and sea level. Firstly, the temperature of land
surface, ocean waters and free atmosphere has been measur ed through fixed
thermometers, balloons in the air and satellites. By these sources, scientists
have produced record of last 130 years, which shows a global warming of
0.65(+ - 0.05degree c) over this period. We also know that 2010 was globally
the warmest years on record.
Secondly, the recorded data of precipitation also reveals that there is upward
trend in global precipitation. It shows that precipitation has increased over
land at high latitudes in northern hemisphere, especially during cold seasons.
As the cyclones, i.e. hurricanes, tornadoes, storms are closely related with
the process of precipitation; the world has experienced more frequent and
stronger hurricanes and storms during the recent past; hurricane katrina in
the us in 2005 and 2010 super flood in Pakistan.
Thirdly, the global sea level has risen by about 20cm over the past 100 years.
Initially, it was believed that the rise in sea level had occurred due to
temperature increase as water expands on heating. But it has been revealed
by relevant data that the 40 per cent increase in the sea level was due to
warming and 60 per cent increase was due to melting of ice. This is pretty
dangerous news as both the poles of earth are covered with ice - arctic and
Antarctic, with huge mass of ice. If melting is accelerated due to global
warming it would cause catastrophic rise in oceans.
2
Global warming is simply defined as an increase in the average global
temperatures. Though, it is an environmental problem, it has serious
implications on the global economics, geopolitics, society, humanity and all
living beings. "global warming is one of the most controversial science issues
of the 21st century, challenging the very structure of our global society", says
mark. Though, there has been controversies between two schools of scientific
thought, one calling it is a myth and the other considering it is a reality, there
is sufficient evidence to support the later. Anthropogenic activities, causing
increased emissions of green house gases, are behind the global warming. It
has been established, that, if not addressed properl y and immediately, it
would have catastrophic impacts.
Global warming means earth is becoming warmer gradually. There is
increase in average global temperatures of air and oceans, accompanied by
widespread melting of glaciers and rising of sea level. The united nations
intergovernmental panel on climate change ( IPCC) in its `synthesis report on
climate change', states that there is clear evidence for a 0.6 OC rise in global
temperatures and 20cm rise in sea level during the 20th century. It predicts
that "global temperatures could rise by 1.4 to 5.8 OC and sea level could rise
by 20 to 88cm by the year 2100." majority of the scientists and research
organizations, including IPCC have reached on consensus that global
warming is caused by massive increase of g reen house gases such as carbon
dioxide (co2) in atmosphere resulting from burning of fossil fuels and
deforestation.
The temperature of earth is maintained by the balance between the heat
energy coming from the sun and the heat energy returned back to space.
Some atmospheric gases: carbon dioxide (co2), methane (ch4), nitrous oxide
(n2ox), chlorofluorocarbons (cfc) and water vapors are important to this
temperature balance. They form the green house blanket in the atmosphere.
This blanket absorbs some of the long wave radiation and re -radiate it back
to surface, which causes the atmosphere to warm up to 350c. Without these
, gases the earth's atmospheric temperature would be 15 to 200c. If more such
gases are added to the atmosphere, the earth's temperature would increase
accordingly. And these are being added enormously.
This is why the global warming is taking place with greater pace due to the
abundant increase in emissions. "the scientists community is largely
persuaded that not only is earth's climate warming, but rate of warming is
accelerating due substantially to, human activity." says dr. Terrence m. Joyce,
senior scientist and director of ocean & climate change institute.
The main evidences of global warming are three basic indicators -
temperature, precipitation and sea level. Firstly, the temperature of land
surface, ocean waters and free atmosphere has been measur ed through fixed
thermometers, balloons in the air and satellites. By these sources, scientists
have produced record of last 130 years, which shows a global warming of
0.65(+ - 0.05degree c) over this period. We also know that 2010 was globally
the warmest years on record.
Secondly, the recorded data of precipitation also reveals that there is upward
trend in global precipitation. It shows that precipitation has increased over
land at high latitudes in northern hemisphere, especially during cold seasons.
As the cyclones, i.e. hurricanes, tornadoes, storms are closely related with
the process of precipitation; the world has experienced more frequent and
stronger hurricanes and storms during the recent past; hurricane katrina in
the us in 2005 and 2010 super flood in Pakistan.
Thirdly, the global sea level has risen by about 20cm over the past 100 years.
Initially, it was believed that the rise in sea level had occurred due to
temperature increase as water expands on heating. But it has been revealed
by relevant data that the 40 per cent increase in the sea level was due to
warming and 60 per cent increase was due to melting of ice. This is pretty
dangerous news as both the poles of earth are covered with ice - arctic and
Antarctic, with huge mass of ice. If melting is accelerated due to global
warming it would cause catastrophic rise in oceans.
2
