Saturday, June 16, 2007

Global warming cause cyclones

Global warming causes cyclones

The above pic show a model how a cyclone is generated by the temperature difference and the wind flow caused by the warmth of the ocean . Typhoons play a significant role in distributing the ocean's heat. Oceans which cover two-thirds of the planet's surface and absorbs massive amounts of heat from the atmosphere. Cyclones whip up the sea like the spinning steel blades of a food mixer and leave its local surface areas cooler than before.
As everyone knows, suns heat converts water into vapor and when that water vapor recondenses in the sky the heat is released. Since water is a polar molecule, it takes a lot of heat to evaporate it, and a correspondingly large amount of heat is released by condensation to rain drops . This heat warms the air, causes further expansion, and reduces the atmospheric pressure below even further. As long as the system remains over warm water this cycle can build and the storm grows in size and windspeed.
Mass extinction of living species.
The first mass extinction of species took place 440 million years ago , and fossil records show an abrupt die-off of two-thirds of the Earth’s species .
375 million years ago another mass extinction occurred that resulted in most of the planet’s fish species dying.
250 million years ago the third, and most severe mass extinction took place.
The fourth mass extinction took place about 205 million years ago at the end of the Triassic Period.
The fifth mass extinction took place about 65 million years ago. The majestic era of the dinosaurs ended when about half of all species died off, having existed 165 million years.
All these happened due to climatic changes. And now a sixth mass extinction is underway.
We have already crossed the threshold into a climactically altered world.

The release of substances (e.g., greenhouse gases) into the atmosphere causes global warming.
Climate models referenced by the IPCC project that global surface temperatures are likely to increase by 1.1 to 6.4 °C between 1990 and 2100.
Arctic sea ice is melting at a far quicker rate than expected. A study published in the latest edition of the journal Geophysical Research Letters, reveals that the actual rate at which summer sea ice had shrunk per decade during the past 50 years was more than three times faster than an average of 18 of the most highly regarded climate simulations. When scientists studied observable data for the some period, including shipping logs, aerial photos and satellite images, they discovered the actual figure for ice loss from 1953 until 2006 to be 7.8 percent.
It is the process by which absorption and emission of infrared radiation by atmospheric gases warms a planet's atmosphere and ocean surface.
Greenhouse gases create a natural greenhouse effect which makes earth a livable planet, and strangely without it, the mean temperatures on Earth would be zero degree and all oceans would freeze. The major natural greenhouse gases are water vapor, which causes about 36–70% of the greenhouse effect (not including clouds); carbon dioxide (CO2), which causes 9–26%; methane (CH4), which causes 4–9%; and ozone, which causes 3–7%. The atmospheric concentrations of CO2 and CH4 have increased by 31% and 149% respectively above pre-industrial levels since 1750. These levels are considerably higher than at any time during the last 650,000 years.
The increased CO2 in the atmosphere warms the Earth's surface and leads to melting of ice near the poles. As the ice melts, land or open water takes its place. Both land and open water are on average less reflective than ice, and thus absorb more solar radiation. This causes more warming, which in turn causes more melting, and this cycle continues.
More melting of polar ice would raise the water level in the seas and all the coastal towns may be flooded in future.
An increase in global temperatures can in turn cause other changes, including sea level rise, and changes in the amount and pattern of precipitation resulting in floods and drought
Heat waves in August, 2003 caused 35,000 deaths in Europe, 15,000 in France alone.
The possible relationship between climate change and tropical cyclones (including hurricanes and typhoons), has been established by researchers and forecasters as represented at the 6th International Workshop on Tropical Cyclones of the World Meteorological Organization WMO(November 2006). Read:

Statement on Tropical Cyclones and Climate Change
The surfaces of most tropical oceans have warmed by 0.25 – 0.5 degree Celsius during the past several decades. Primary cause of the rise in global mean surface temperature in the past 50 years is the increase in greenhouse gas concentrations.
The global community of tropical cyclone researchers and forecasters as represented at the 6th International. Human-induced climate change causes tropical cyclones, including hurricanes and typhoons.

a) There have been a number of recent high-impact tropical cyclone events around the globe. These include 10 landfalling tropical cyclones in Japan in 2004, five tropical cyclones affecting the Cook Islands in a five-week period in 2005, Cyclone Gafilo in Madagascar in 2004, Cyclone Larry in Australia in 2006, Typhoon Saomai in China in 2006, and the extremely active 2004 and 2005 Atlantic tropical cyclone seasons - including the catastrophic socio-economic impact of Hurricane Katrina.
b) Some recent scientific articles have reported a large increase in tropical cyclone energy, numbers, and wind-speeds in some regions during the last few decades in association with warmer sea surface temperatures. Other studies report that changes in observational techniques and instrumentation are responsible for these increases.

3. The recent increase in societal impact from tropical cyclones has largely been caused by rising
concentrations of population and infrastructure in coastal regions.

6. It is likely that some increase in tropical cyclone peak wind-speed and rainfall will occur if the
climate continues to warm. Model studies and theory project a 3-5% increase in wind-speed per
degree Celsius increase of tropical sea surface temperatures.

10. If the projected rise in sea level due to global warming occurs, then the vulnerability to tropical yclone storm surge flooding would increase.

Stronger storms predicted in future

An increase of intensity of hurricanes by about one-half category on the Saffir-Simpson scale was simulated for an 80 year build-up of atmospheric CO2 at 1% per year (compounded). For hurricane wind speeds, the model shows a sensitivity of about 4% per degree Celsius increase in tropical sea surface temperatures.

The number of category 4 and 5 hurricanes has almost doubled globally over the past three decades.

1 comment:

alvinwriter said...

Global warming causes heating of the oceans which cause unnatural storm intensities. Ancient geological records unearthed by scientists show that the Earth's climate has changed much in the past. It's possible that findings made concerning the our planet's past can help make sense of what we're experiencing these days.

Ancient British Bog Provides Clue to Global Warming:

- Alvin from TheScienceDesk at