GISS, since the first data recorded andor reconstructed, mean temperature change in land area was increased with the amount ± 1.4 °C per 5 years and in ocean was
increased with the amount ± 0.7 °C per 5 years or land area has double increasing value than ocean Figure 4.1 a. The warmer of land area can be because land
properties soil, rock, sand etc. is better conductor and can preserve heat that it received than water properties even both object receive the same heat.
Data from NASA GISS also shows hemispheric temperature has been change and linearly increase where the increasing in northern hemisphere is different with
southern hemisphere. Since the first year data record until 2010, the 5 years mean of increasing in northern hemisphere was ± 1.25 °C and was ± 0.85 °C in southern
hemisphere Figure 4.1 b. It can possibly caused by the land area in northern hemisphere is larger than southern part so that human air pollution that can
trapped emitted energy which is one of majoring factor in global warming in northern part is higher than in the southern part. That possibility can be supported
by data from World Bank 2011 that shows the air pollution contribution of each country.
Developed countries are the countries with the highest contribution of CO
2
emissions. In 2006, China contributed 6.103x10
6
tons of CO
2
emissions or 21.5 of total CO
2
emissions. United states contributed 5.752x10
6
tons of CO
2
emissions or 20.2 of total CO
2
emissions. Russia contributed 5.5 of total CO
2
emissions; India contributed 5.3, Japan contributed 4.6, Germany contributed 2.8,
United Kingdom contributed 2.0, Canada contributed 1.9, while South Korea and Italy has the same contribution with 1.7 of total CO
2
emissions per country. Those top ten countries with the highest CO
2
emissions are located in northern hemisphere.
If we take a look from the view of top ten most polluted city in the world, data in 2004 shows that only Jakarta Indonesia was the most polluted city which is
located in southern hemisphere. Even if we take a look from view of top ten countries with the highest per capita CO
2
emissions which is nit correlated directly to atmosphere and global warming, data in 2006 shows that countries
from northern hemisphere is the countries with the highest contribution exclude Australia. The complete top ten countries with highest contribution of CO
2
emission, top ten most polluted cities by particulate matter, and ten countries with highest carbon dioxide emissioncapita can be seen completely in Appendix 1.
2.2 Global Climate Change
Global climate change is a change in the long-term weather patterns that characterize the regions of the world. The term weather refers to the short-term
daily changes in temperature, wind, andor precipitation of a region Merritts et al.
1998. The sun influences weather, where the sun heats the earths atmosphere and its surface causing air and water to move around the planet. The result can be
as simple as a slight breeze or as complex as the formation of a tornado. Some of the suns incoming long wave radiation is reflected back to space by aerosols. In
addition, some of the suns energy that has entered Earths atmosphere is reflected into space by the Earth’s surface the reflectivity of Earths surface is called
albedo. Both of these reflective processes have a cooling affect on the planet. The greenhouse effect is a warming process that balances Earths cooling
processes. During this process, sunlight passes through Earths atmosphere as short-wave radiation. In atmosphere some of long wave radiation is absorbed by
certain gases called greenhouse gases. Greenhouse gases include carbon dioxide CO
2
, chlorofluorocarbons CFCs, methane CH
4
, nitrous oxide N
2
0, tropospheric ozone O
3
, and water vapor. Each molecule of greenhouse gas becomes energized by the long wave radiation. The energized molecules of gasses
then emit heat energy in all directions. By emitting heat energy toward Earth, greenhouse gases increase Earths temperature Dasgupta and Meisner, 2009.
The greenhouse effect is a natural occurrence that maintains Earths average temperature at approximately 60 degrees Fahrenheit. The greenhouse effect is a
necessary phenomenon that keeps all Earths heat from escaping to the outer atmosphere. Without the greenhouse effect, temperatures on Earth would be much
lower than they are now, and the existence of life on this planet would not be possible. However, too many greenhouse gases in Earths atmosphere could
increase the greenhouse effect. This could result an increases in mean global temperatures as well as changes in precipitation patterns.
When weather patterns for an area change in one direction over long periods of time, they can result in a net climate change for that area the key concept in
climate change is time. The real threat of climate change lies in how rapidly the change occurs. For example, over the past 120 years, the mean global temperature
appears to have risen 2 to 8 degrees Celsius. These temperatures changes are depicted in the graph below from the IPCC 2001.
Figure 2.2. The increasing of global temperature The geological record, the physical evidence of the results of processes that
have occurred on Earth since it was formed, provides evidence of climate changes similar in magnitude to those in the above graph. This means during the history of
the earth, there have been changes in global temperatures similar in size to these changes Schlesinger, 1991. However, the past changes occurred at much slower
rates, and thus they were spread out over long periods of time. The slow rate of change allowed most species enough time to adapt to the new climate. The current
and predicted rates of temperature change, on the other hand, may be harmful to ecosystems. This is because these rates of temperature change are much faster
than those of Earths past. Many species of plants, animals, and microorganisms may not have enough time to adapt to the new climate.
