Sunday, November 28, 2010

The Effects of Increasing Temperature

Searching for information on the possible effects of continued increase in the temperature lead me to this article. I quoted some of the explanation from the Independent website. For full text you can visit the site.



The average rise will not be spread uniformly, and temperatures over land will be significantly higher (5.5C on average) than over the ocean, as the land heats up more quickly than the sea.


Temperatures at higher latitudes, particularly in the Arctic, will rise much more steeply in a four-degree world as they experience climate feedbacks due to the loss of sea ice and snow cover.Already, scientists have detected signs of unusual permafrost melting in Siberia and the release of vast quantities of underground methane, a powerful greenhouse gas.


The summer of 2003, when night-time temperatures were far beyond normal, caused many thousands of deaths through heat stroke and other related conditions. A four-degree world will make such summerscommonplace, causing environmental as well as medical problems.


A growing population puts pressure on water supplies, which will be exacerbated in regions of the world that will experience the greatest increase in numbers of people, such as India. In a four-degree world, however, the problems of water shortages will be primarily caused by climate change – a double whammy for the most populated countries.


At higher temperatures, the Amazon rainforest is vulnerable to drought and uncontrolled spread of fires. Some climate models predict increased rainfall, while other "more realistic" computer projections predict severe drying in the Amazon.


Sea level rise is inevitable in a warmer world, but the problem will be significantly worse in a four-degree world because of melting ice sheets, glaciers and thermal expansion. Low-lying, heavily populated river deltas and coastal regions are especially vulnerable to flooding. Small oceanic islands will experience increased storm surges and problems with increased soil salinity.


At 4°C, virtually all cereal-growing regions of the world experience crop failures or shortages. The areas affected most will be semi-arid regions where agriculture is already difficult, such as parts of sub-Saharan Africa. Some regions may become uninhabitable with widespread famine


Saturday, November 27, 2010

Pictures of Global Warming

Here are some pictures of global warming.

Monday, March 8, 2010

What is El Nino and El Nina Phenomenon

This is what says about el nino phenomenon.

El Niño-Southern Oscillation, often called simply ENSO, is a climate pattern that occurs across the tropical Pacific Ocean on average every five years, but over a period which varies from three to seven years, and is therefore, widely and significantly, known as "quasi-periodic." ENSO is best-known for its association with floods, droughts and other weather disturbances in many regions of the world, which vary with each event. Developing countries dependent upon agriculture and fishing, particularly those bordering the Pacific Ocean, are the most affected.

ENSO is composed of an oceanic component, called El Niño (or La Niña), which is characterized by warming or cooling of surface waters in the tropical eastern Pacific Ocean, and an atmospheric component, the Southern Oscillation, which is characterized by changes in surface pressure in the tropical western Pacific. The two components are coupled: when the warm oceanic phase (known as El Niño) is in effect, surface pressures in the western Pacific are high, and when the cold phase is in effect (La Niña), surface pressures in the western Pacific are low.[2][3] Mechanisms that cause the oscillation remain under study.

In popular usage, El Niño-Southern Oscillation is often called just "El Niño". El Niño is Spanish for "the boy" and refers to the Christ child, because periodic warming in the Pacific near South America is usually noticed around Christmas.[4] "La Niña" is Spanish for "the girl."


El Niño is defined by sustained differences in Pacific-Ocean surface temperatures when compared with the average value. The accepted definition is a warming or cooling of at least 0.5°C (0.9°F) averaged over the east-central tropical Pacific Ocean. When this happens for less than five months, it is classified as El Niño or La Niña conditions; if the anomaly persists for five months or longer, it is called an El Niño or La Niña "episode."[5] Typically, this happens at irregular intervals of 2–7 years and lasts nine months to two years.[6]

The first signs of an El Niño are:

1. Rise in surface pressure over the Indian Ocean, Indonesia, and Australia
2. Fall in air pressure over Tahiti and the rest of the central and eastern Pacific Ocean
3. Trade winds in the south Pacific weaken or head east
4. Warm air rises near Peru, causing rain in the northern Peruvian deserts
5. Warm water spreads from the west Pacific and the Indian Ocean to the east Pacific. It takes the rain with it, causing extensive drought in the western Pacific and rainfall in the normally dry eastern Pacific.

El Niño's warm current of nutrient-poor tropical water, heated by its eastward passage in the Equatorial Current, replaces the cold, nutrient-rich surface water of the Humboldt Current. When El Niño conditions last for many months, extensive ocean warming occurs and its economic impact to local fishing for an international market can be serious.[7]
[edit] Early stages and characteristics of El Niño
5-day running mean of MJO. Note how it moves eastward with time.

Although its causes are still being investigated, El Niño events begin when trade winds, part of the Walker circulation, falter for many months. A series of Kelvin waves—relatively warm subsurface waves of water a few centimetres high and hundreds of kilometres wide—cross the Pacific along the equator and create a pool of warm water near South America, where ocean temperatures are normally cold due to upwelling. The Pacific Ocean is a heat reservoir that drives global wind patterns, and the resulting change in its temperature alters weather on a global scale. Rainfall shifts from the western Pacific toward the Americas, while Indonesia and India become drier.