Thursday, September 17, 2009
& Global Warming By Thiru
WHAT IS GLOBAL WARMING Global warming is the increase in the average temperature of the Earth's near-surface air and oceans since the mid-20th century and its projected continuation. Global surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the last century. An increase in global temperature will cause sea levels to rise and will change the amount and pattern of precipitation, probably including expansion of subtropical deserts.[7] The continuing retreat of glaciers, permafrost and sea ice is expected, with warming being strongest in the Arctic. Other likely effects include increases in the intensity of extreme weather events, species extinctions, and changes in agricultural yields.
www.wikipidia.com
Greenhouse Gases and Global Warming
While many greenhouse gases occur naturally and are needed to create the greenhouse effect that keeps the Earth warm enough to support life, human use of fossil fuels is the main source of excess greenhouse gases. By driving cars, using electricity from coal-fired power plants, or heating our homes with oil or natural gas, we release carbon dioxide and other heat-trapping gases into the atmosphere. Deforestation is another significant source of greenhouse gases, because fewer trees means less carbon dioxide conversion to oxygen.
During the 150 years of the industrial age, the atmospheric concentration of carbon dioxide has increased by 31 percent. Over the same period, the level of atmospheric methane has risen by 151 percent, mostly from agricultural activities such as raising cattle and growing rice.
The Consequences of Global Warming
As the concentration of greenhouse gases grows, more heat is trapped in the atmosphere and less escapes back into space. This increase in trapped heat changes the climate and alters weather patterns, which may hasten species extinction, influence the length of seasons, cause coastal flooding, and lead to more frequent and severe storms
http://environment.about.com/od/faqglobalwarming/f/globalwarming.htm
Physical impacts
Effects on weather
Increasing temperature is likely to lead to increasing precipitation [10][11] but the effects on storms are less clear. Extratropical storms partly depend on the temperature gradient, which is predicted to weaken in the northern hemisphere as the polar region warms more than the rest of the hemisphere.[12]
Global warming may be responsible in part for some trends in natural disasters such as extreme weather.
Based on future projections of climate change, the IPCC report makes a number of predictions.[3] It is predicted that over most land areas, the frequency of warm spells/heat waves will very likely increase. It is likely that:
Increased areas will be affected by drought
There will be increased intense tropical cyclone activity
There will be increased incidences of extreme high sea level (excluding tsunamis)
Storm strength leading to extreme weather is increasing, such as the power dissipation index of hurricane intensity.[13] Kerry Emanuel writes that hurricane power dissipation is highly correlated with temperature, reflecting global warming.[14] However, a further study by Emanuel using current model output concluded that the increase in power dissipation in recent decades cannot be completely attributed to global warming[15]. Hurricane modeling has produced similar results, finding that hurricanes, simulated under warmer, high-CO2 conditions, are more intense, however, hurricane frequency will be reduced.[16] Worldwide, the proportion of hurricanes reaching categories 4 or 5 – with wind speeds above 56 metres per second – has risen from 20% in the 1970s to 35% in the 1990s.[17] Precipitation hitting the US from hurricanes has increased by 7% over the twentieth century.[18][19][20] The extent to which this is due to global warming as opposed to the Atlantic Multidecadal Oscillation is unclear. Some studies have found that the increase in sea surface temperature may be offset by an increase in wind shear, leading to little or no change in hurricane activity.[21] Hoyos et al. (2006) have linked the increasing trend in number of category 4 and 5 hurricanes for the period 1970-2004 directly to the trend in sea surface temperatures.[22]
Increases in catastrophes resulting from extreme weather are mainly caused by increasing population densities, and anticipated future increases are similarly dominated by societal change rather than climate change.[23] The World Meteorological Organization explains that “though there is evidence both for and against the existence of a detectable anthropogenic signal in the tropical cyclone climate record to date, no firm conclusion can be made on this point.”[24] They also clarified that “no individual tropical cyclone can be directly attributed to climate change.”[24]
Thomas Knutson and Robert E. Tuleya of NOAA stated in 2004 that warming induced by greenhouse gas may lead to increasing occurrence of highly destructive category-5 storms.[25] In 2008, Knutson et al. found that Atlantic hurricane and tropical storm frequencies could reduce under future greenhouse-gas-induced warming.[26] Vecchi and Soden find that wind shear, the increase of which acts to inhibit tropical cyclones, also changes in model-projections of global warming. There are projected increases of wind shear in the tropical Atlantic and East Pacific associated with the deceleration of the Walker circulation, as well as decreases of wind shear in the western and central Pacific.[27] The study does not make claims about the net effect on Atlantic and East Pacific hurricanes of the warming and moistening atmospheres, and the model-projected increases in Atlantic wind shear. [28]
A substantially higher risk of extreme weather does not necessarily mean a noticeably greater risk of slightly-above-average weather.[29] However, the evidence is clear that severe weather and moderate rainfall are also increasing. Increases in temperature are expected to produce more intense convection over land and a higher frequency of the most severe storms
Cost of more extreme weather
See also: List_of_costliest_Atlantic_hurricanes
As the World Meteorological Organization explains, “recent increase in societal impact from tropical cyclones has largely been caused by rising concentrations of population and infrastructure in coastal regions.”[24] Pielke et al. (2008) normalized mainland U.S. hurricane damage from 1900–2005 to 2005 values and found no remaining trend of increasing absolute damage. The 1970s and 1980s were notable because of the extremely low amounts of damage compared to other decades. The decade 1996–2005 has the second most damage among the past 11 decades, with only the decade 1926–1935 surpassing its costs. The most damaging single storm is the 1926 Miami hurricane, with $157 billion of normalized damage.[23]
The American Insurance Journal predicted that “catastrophe losses should be expected to double roughly every 10 years because of increases in construction costs, increases in the number of structures and changes in their characteristics.”[33] The Association of British Insurers has stated that limiting carbon emissions would avoid 80% of the projected additional annual cost of tropical cyclones by the 2080s. The cost is also increasing partly because of building in exposed areas such as coasts and floodplains. The ABI claims that reduction of the vulnerability to some inevitable effects of climate change, for example through more resilient buildings and improved flood defences, could also result in considerable cost-savings in the longterm.
Oceans
The role of the oceans in global warming is a complex one. The oceans serve as a sink for carbon dioxide, taking up much that would otherwise remain in the atmosphere, but increased levels of CO2 have led to ocean acidification. Furthermore, as the temperature of the oceans increases, they become less able to absorb excess CO2. Global warming is projected to have a number of effects on the oceans. Ongoing effects include rising sea levels due to thermal expansion and melting of glaciers and ice sheets, and warming of the ocean surface, leading to increased temperature stratification. Other possible effects include large-scale changes in ocean circulation.
http://en.wikipedia.org/wiki/Effects_of_global_warming#Physical_impacts
www.wikipidia.com
Greenhouse Gases and Global Warming
While many greenhouse gases occur naturally and are needed to create the greenhouse effect that keeps the Earth warm enough to support life, human use of fossil fuels is the main source of excess greenhouse gases. By driving cars, using electricity from coal-fired power plants, or heating our homes with oil or natural gas, we release carbon dioxide and other heat-trapping gases into the atmosphere. Deforestation is another significant source of greenhouse gases, because fewer trees means less carbon dioxide conversion to oxygen.
During the 150 years of the industrial age, the atmospheric concentration of carbon dioxide has increased by 31 percent. Over the same period, the level of atmospheric methane has risen by 151 percent, mostly from agricultural activities such as raising cattle and growing rice.
The Consequences of Global Warming
As the concentration of greenhouse gases grows, more heat is trapped in the atmosphere and less escapes back into space. This increase in trapped heat changes the climate and alters weather patterns, which may hasten species extinction, influence the length of seasons, cause coastal flooding, and lead to more frequent and severe storms
http://environment.about.com/od/faqglobalwarming/f/globalwarming.htm
Physical impacts
Effects on weather
Increasing temperature is likely to lead to increasing precipitation [10][11] but the effects on storms are less clear. Extratropical storms partly depend on the temperature gradient, which is predicted to weaken in the northern hemisphere as the polar region warms more than the rest of the hemisphere.[12]
Global warming may be responsible in part for some trends in natural disasters such as extreme weather.
Based on future projections of climate change, the IPCC report makes a number of predictions.[3] It is predicted that over most land areas, the frequency of warm spells/heat waves will very likely increase. It is likely that:
Increased areas will be affected by drought
There will be increased intense tropical cyclone activity
There will be increased incidences of extreme high sea level (excluding tsunamis)
Storm strength leading to extreme weather is increasing, such as the power dissipation index of hurricane intensity.[13] Kerry Emanuel writes that hurricane power dissipation is highly correlated with temperature, reflecting global warming.[14] However, a further study by Emanuel using current model output concluded that the increase in power dissipation in recent decades cannot be completely attributed to global warming[15]. Hurricane modeling has produced similar results, finding that hurricanes, simulated under warmer, high-CO2 conditions, are more intense, however, hurricane frequency will be reduced.[16] Worldwide, the proportion of hurricanes reaching categories 4 or 5 – with wind speeds above 56 metres per second – has risen from 20% in the 1970s to 35% in the 1990s.[17] Precipitation hitting the US from hurricanes has increased by 7% over the twentieth century.[18][19][20] The extent to which this is due to global warming as opposed to the Atlantic Multidecadal Oscillation is unclear. Some studies have found that the increase in sea surface temperature may be offset by an increase in wind shear, leading to little or no change in hurricane activity.[21] Hoyos et al. (2006) have linked the increasing trend in number of category 4 and 5 hurricanes for the period 1970-2004 directly to the trend in sea surface temperatures.[22]
Increases in catastrophes resulting from extreme weather are mainly caused by increasing population densities, and anticipated future increases are similarly dominated by societal change rather than climate change.[23] The World Meteorological Organization explains that “though there is evidence both for and against the existence of a detectable anthropogenic signal in the tropical cyclone climate record to date, no firm conclusion can be made on this point.”[24] They also clarified that “no individual tropical cyclone can be directly attributed to climate change.”[24]
Thomas Knutson and Robert E. Tuleya of NOAA stated in 2004 that warming induced by greenhouse gas may lead to increasing occurrence of highly destructive category-5 storms.[25] In 2008, Knutson et al. found that Atlantic hurricane and tropical storm frequencies could reduce under future greenhouse-gas-induced warming.[26] Vecchi and Soden find that wind shear, the increase of which acts to inhibit tropical cyclones, also changes in model-projections of global warming. There are projected increases of wind shear in the tropical Atlantic and East Pacific associated with the deceleration of the Walker circulation, as well as decreases of wind shear in the western and central Pacific.[27] The study does not make claims about the net effect on Atlantic and East Pacific hurricanes of the warming and moistening atmospheres, and the model-projected increases in Atlantic wind shear. [28]
A substantially higher risk of extreme weather does not necessarily mean a noticeably greater risk of slightly-above-average weather.[29] However, the evidence is clear that severe weather and moderate rainfall are also increasing. Increases in temperature are expected to produce more intense convection over land and a higher frequency of the most severe storms
Cost of more extreme weather
See also: List_of_costliest_Atlantic_hurricanes
As the World Meteorological Organization explains, “recent increase in societal impact from tropical cyclones has largely been caused by rising concentrations of population and infrastructure in coastal regions.”[24] Pielke et al. (2008) normalized mainland U.S. hurricane damage from 1900–2005 to 2005 values and found no remaining trend of increasing absolute damage. The 1970s and 1980s were notable because of the extremely low amounts of damage compared to other decades. The decade 1996–2005 has the second most damage among the past 11 decades, with only the decade 1926–1935 surpassing its costs. The most damaging single storm is the 1926 Miami hurricane, with $157 billion of normalized damage.[23]
The American Insurance Journal predicted that “catastrophe losses should be expected to double roughly every 10 years because of increases in construction costs, increases in the number of structures and changes in their characteristics.”[33] The Association of British Insurers has stated that limiting carbon emissions would avoid 80% of the projected additional annual cost of tropical cyclones by the 2080s. The cost is also increasing partly because of building in exposed areas such as coasts and floodplains. The ABI claims that reduction of the vulnerability to some inevitable effects of climate change, for example through more resilient buildings and improved flood defences, could also result in considerable cost-savings in the longterm.
Oceans
The role of the oceans in global warming is a complex one. The oceans serve as a sink for carbon dioxide, taking up much that would otherwise remain in the atmosphere, but increased levels of CO2 have led to ocean acidification. Furthermore, as the temperature of the oceans increases, they become less able to absorb excess CO2. Global warming is projected to have a number of effects on the oceans. Ongoing effects include rising sea levels due to thermal expansion and melting of glaciers and ice sheets, and warming of the ocean surface, leading to increased temperature stratification. Other possible effects include large-scale changes in ocean circulation.
http://en.wikipedia.org/wiki/Effects_of_global_warming#Physical_impacts
Your Attention Is All Tht I Require ,
@ 11:31 AM
HELLO THERE ,
We 2N2'ers, are super FRIENDLY & HYPER! :DDD
Express, Normal & Normal Tech. We're just in different streams studying at our comfortable pace. So, don't look down on us. :)
2N2'09-ers ,
Form Teacher : Mdm Salimah
Co Form : Miss Wang Xiao Jun
English : Miss Norazleen
Maths : Mr Goh Yong Yeu / Mr Oh
Science : Ms Judith
Physical Education : Mr Joe Tan
Literature: Miss Lim Bin
Music : Next Semester.
Geography : Next Semester.
History : Mdm Salimah
F & N : Mdm Paramjit
D & T : Mr Eric Micahel Basuki
Chinese : Ms Wang Xiao Jun
Malay : Ms Farrah
--------------------------------------
01.✩CANDY✩
02.✩CHARRISSA✩
03.✩FILIAH✩
04.✩FIONA✩
05.✩JESSIKA✩
06.✩KAR YEE✩
07.✩KHAMISAH✩
08.✩MICHELLE✩
09.✩SHERYL✩
10.✩MINGZHU✩
11.✩SURIATI✩
12.✩QUSYAIRAH✩
13.✩SALEHA✩
14.✩SYAQINAH✩
15.✩JIA HUI✩
16.✩AMANDA✩
17.✩REGINE✩
18.✩ZHI YAN✩
19.✩YASMIN✩
20.✩LI HAO✩
21.✩IVAN✩
22.✩DARREN✩
23.✩ISAAC✩
24.✩WINSTON✩
25.✩EDSEL✩
26.✩GABRIEL✩
27.✩LEON✩
28.✩EDWIN✩
29.✩JUNHAO✩
30.✩RAMADHAN✩
31.✩RIFQI✩
32.✩ROSHAHFIZAN✩
33.✩NASRUN✩
34.✩JUNJIE✩
35.✩RYAN✩
36.✩STANLEY✩
37.✩WENHAO✩
38.✩LAIHUAT✩
39.✩YONGHUAY✩
40.✩LIANGJIN✩
41.✩THIRU✩
42.✩JINGYE✩
43.✩SYAHMI✩
Co Form : Miss Wang Xiao Jun
English : Miss Norazleen
Maths : Mr Goh Yong Yeu / Mr Oh
Science : Ms Judith
Physical Education : Mr Joe Tan
Literature: Miss Lim Bin
Music : Next Semester.
Geography : Next Semester.
History : Mdm Salimah
F & N : Mdm Paramjit
D & T : Mr Eric Micahel Basuki
Chinese : Ms Wang Xiao Jun
Malay : Ms Farrah
--------------------------------------
01.✩CANDY✩
02.✩CHARRISSA✩
03.✩FILIAH✩
04.✩FIONA✩
05.✩JESSIKA✩
06.✩KAR YEE✩
07.✩KHAMISAH✩
08.✩MICHELLE✩
09.✩SHERYL✩
10.✩MINGZHU✩
11.✩SURIATI✩
12.✩QUSYAIRAH✩
13.✩SALEHA✩
14.✩SYAQINAH✩
15.✩JIA HUI✩
16.✩AMANDA✩
17.✩REGINE✩
18.✩ZHI YAN✩
19.✩YASMIN✩
20.✩LI HAO✩
21.✩IVAN✩
22.✩DARREN✩
23.✩ISAAC✩
24.✩WINSTON✩
25.✩EDSEL✩
26.✩GABRIEL✩
27.✩LEON✩
28.✩EDWIN✩
29.✩JUNHAO✩
30.✩RAMADHAN✩
31.✩RIFQI✩
32.✩ROSHAHFIZAN✩
33.✩NASRUN✩
34.✩JUNJIE✩
35.✩RYAN✩
36.✩STANLEY✩
37.✩WENHAO✩
38.✩LAIHUAT✩
39.✩YONGHUAY✩
40.✩LIANGJIN✩
41.✩THIRU✩
42.✩JINGYE✩
43.✩SYAHMI✩
