2. What is global warming?
3. Green house effect
4. Evidences of global warming/climate change
c) Rise in sea level.
5. Causes of global warming-emissions
6. Sources of emissions
7. Who are responsible for green house emissions?
8. Possible impacts of global warming:
a) Most affected would be marginalised communities,
b) Coastal areas,
c) Frequent and strong storms and floods,
d) Health problems,
e) Ecosystem destruction,
f) Agricultural loss (Food insecurity).
9. Unpredictable surprises
10. Threshold level
11. Strategies to mitigate global warming:
a) Transforming to renewable sources of energy,
b) Energy conservation and efficiency,
c) Individual efforts.
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 properly 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 0C rise
A R Khan Chachar CSS_2016
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 0C and sea level could rise by 20 to 88cm by
the year 2100.” Majority of the scientists and research organisations, including IPCC have
reached on consensus that global warming is caused by massive increase of green house
gases such as Carbon dioxide (Co2) in atmosphere resulting from burning of fossil fuels and
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
vapours 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
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
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 measured 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.
The magnitude of the impacts warrants seriously looking into the responsible factors for
emissions in order to devise effective strategies to cope with this peril. There are many
sources/agents which are responsible for emissions of green house gases – resulting mainly
from the burning of fossil fuels and deforestation. Industrial processes, power generation,
transportation and domestic consumption of fossil fuels are major sources of anthropogenic
emission. Unfortunately, the fossil fuel i.e. oil, coal, natural gas supply 85 per cent of energy
supply whereas the clean forms of energy i.e. nuclear , biomass and hydrogen only form 15
per cent of energy supply.
On the other hand, cutting of trees for settlements and natural fire incidents like the
summer fire in Australia and unusual fire in Russia in 2010, due to high temperatures, are
also causing deforestation at massive level. In this way the forests, which are major source
of balancing CO2, are also decreasing resulting in its increase in the atmosphere.
Since, the emissions are proportional to the consumption; these are not evenly distributed
around the world. North America is a leading emitter followed by Europe and Asia. Together
they make 90 per cent of the global industrially produced CO2. The developed countries
have emitted much more than developing countries. Besides, the developing countries are
striving for economic progress, subsequently increasing emissions as economic development
is closely associated with energy production. Now, all the countries, particularly developed
countries have to share responsibility to cut the emissions for the purpose of humanity
otherwise we are going to suffer the possible implications.
Global warming is going to divest communities that are already the most marginalised in
world. These are the communities that are least responsible for the industrial and historical
emissions that created the problem. However, future climate change will have impacts on all
parts of human society, including coastal regions, storms and floods, health and water
resources, agriculture and biodiversity. Some of the impacts are discussed separately.
One; the coast line regions are most vulnerable. As the UN’s panel on climate has reported
that sea level could rise by 20-88 cm in next 100 years, this is a serious problem for coastal
areas which will be more prone to storms and floods. In response, the bigger and developed
countries would have to build higher walls on the coasts but still they will have to lose some
agricultural land. However, the small island countries like Maldives face dire situation. The
sea rise would flood up the dry land, making these islands inhabitable. Another country,
Bangladesh which is deltaic region would lose considerable portion of land and its
agriculture – a prime source of livelihood there will be destroyed.
Two; storms and floods are major natural hazards. The records show that the temperature
regions, particularly in the northern hemisphere, have witnessed more storms over the last
50 years. Two-fifth of the world population lives under the monsoon belt. Monsoons are
caused mainly by temperature difference between oceans and continents. This difference
will increase and the monsoons, which are normally life-giving rains, would exacerbate
tremendously flooding the regions and destroying the agriculture – the major economic
activity in the developing countries.
diseases and injury due to extreme events; increased frequency of diarrhea and
cardiovascular diseases. By far the most important threat to human health is access to fresh
drinking water. Though, the runoff is projected to increase by 10 to 40 per cent by mid
century at higher latitudes but the negative impacts of global warming on fresh water
system outweigh its benefits.
Currently, approximately 1.7 billion people, a third of world population, live in countries that
are water stressed. IPCC suggests that with the projected global population increase and
the expected climate change, five billion people may experience water stress by 2025.
Fourth; ecosystem which is an essential component for biodiversity, is going to be seriously
affected by global warming. The species at maximum threats are: The mountain gorilla in
Africa, amphibious Bengal tiger, polar bears and penguins, etc. The reason for threat to
these species is that they are unable to migrate in response to climate change due to
human activity and urbanisation. Another example of an ecosystem under threat is coastal
protection. There are evidences that the coral reefs are diminishing due to temperature
increase; which will disturb basic food chain in marine life.
Fifth; the most worrying concern of climate change is the effect it will have on agriculture.
The world is already facing food crisis. According to UN, more than 800 million go to sleep
hungry every night. Increase in temperature would have two effects: first, in higher
latitudes it will increase food production due by moderating temperatures and increased
CO2; it second, it will reduce the crop yield in the low latitudes due to higher temperatures
and destruction of agricultural land by salinity. Generally, there will be a drop in food
production in both the developed and less developed countries.
The above impacts assume that there is a linear relationship between the increase in
temperatures and its implications. However, there is increasing concern among the scientists
that climate change may occur abruptly and explode surprises for humanity- beyond its
control. It is observed that environment is changing at a faster rate than expected. A report
by a US National Academy of Science (NAS) says, “Available evidence suggests that abrupt
climate changes are not only possible but likely in the future, potentially with large impacts
on ecosystem and societies”.
Moreover, there is a point of no return- “threshold”, after which warming may become
unstoppable. The earth’s climate can change abruptly when the responsible factors reach
the thresholds. Most scientists think that the point lies not far beyond 20C hotter. It is the
point at which anthropogenic warming can trigger huge release of Carbon dioxide from
warming oceans or similar releases of both CO2 and CH4 from melting permafrost, or both.
To limit warming to 20C we must stabilise concentration of green house gases in the
atmosphere at a specific ‘stabilisation level’.
Knowing the dangerous consequences of inaction, the world needs to act to check the global
warming. As the global warming is caused by anthropogenic emissions, the most logical
approach to this problem would be to cut emissions significantly. This, however, has a major
implication for the world economy- the energy of which is mainly based on fossil fuel
burning. Several efforts have been spearheaded in the past but consensus has not been
reached due to contentious position of some most industrialised countries.
From the Kyoto Protocol 1997 through Copenhagen, 2009 to Cancun Conference 2010, the
world leaders have been unable to agree on substantial cuts in emissions and adequate
funding for adoption. Though, there has been some progress in foundation work along with
commitments from the world leaders to tackle this danger to planet earth, there is a long
way to go for effective action.
Being the developed countries these are well equipped, technologically, to cut the emission
by transforming their economies from fossil fuel-based energy to renewable resource
energy. The solar energy available is the most abundant form of energy available to
humans. Wind energy is another plenty source of energy. Nuclear source is also a nonpollutant
source of energy. The developed countries should not only explode this source but
they should also support/help the underdeveloped countries to generate electricity from this
source. We need to understand that we have to switch over to these sources of energy as
the fossil fuels are bound to be finished by the increasing levels of consumption; so why
late, why not now?
Furthermore, the effort at the international level is not the only way to control global
warming; all the people can play their individual role as well. After all are the end users of
all that is produced in the industries and energy sector. Individuals can help reduce the
green house emissions by many ways like: driving less, sharing a car with a friend or
colleague to office, eating local, improving vehicles’ fuel efficiency, consuming less, using
less electricity (and saving money), energy efficiency at work and home and by reducing
waste products. These acts would serve the purpose of emission reduction in two ways:
One; the less- consumption would result less production and subsequently less burning of
fuels. Two; it will generate a moral pressure on the industries and governments to realise
the dilemma and agree to the emission reduction policy.
There is a feasible counter balance to reduce CO2 from atmosphere by growing forests on
land and vegetation in sea but it will not do much. Ultimately, a combination of improved
energy efficiency and alternative energy resources is the way to mitigate global warming.
Though it will cost us but ‘the earlier effective action is taken, the less costly it will be”, says
Sir Nicholas Stern, the Chief Economist at World Bank. We need to act now, we need to act
before it’s too late, as the major threat from global warming is its unpredictability.
The global warming has become the real test of the foundations of our modern society,
civilisation and democracy. Its anthropogenic causes are amply proved. Its implications have
started hitting humanity, which are too harmful to be ignored. The solutions are at hand.
Therefore, the world leaders have responsibility to respond to it effectively for the cause of
humanity – our future generation. “Climate change, and what we do about it, will
define us, our era, and ultimately the global legacy we leave for future
generations”, says Ban Ki Moon.