A tornado is a violent rotating column of air extending from a thunderstorm to the ground.

Tornadoes are mesugered by the Fujita scale, and the can go from an F0 tornado to an F5 tornado.

An F0 tornado will likely damage tress but they dont have to the power to destroy substantial structure, an F5 however, is capable of ripping of buildings of their foundations.

Tornadoes are not very common in portugal, but in USA for example, they occur very often, here are some safety tips concerning tornadoes:

-Before it occurs make sure everyone knows where to go in case a tornado threatens, prepare a disaster supplies kit for your home and car than includes a first aid kit, canned food and a can opener, bottled water, battery-operated radio, flashlight, protective clothing and written instructions on how to turn off electricity, gas, and water.

-During the tornado is very important to be in a place without windows so go to the basement, if you don't have a basement go to an interior room without windows on the lowest floor such as a bathroom or closet. Stay away from fallen power lines and stay out of damaged areas.

-After a tornado stay indoors until it is safe to come out. Check for injured or trapped people, without putting yourself in danger.

The Global Warming

The global warming is a climatic problem of large extension. In the last 150 years, we can verify an increase of the global surface medium temperature. The meaning of this increase is under analysis by the world scientists.
A big part of the scientific comunity believes that the increasing concentration of human origin pollutants in the atmosphere is causing the greenhouse effect.
The earth receives radiation from the sun and returns most of it into space by radiation heat. The air pollutants retain a part of that radiation, that would be reflected into space, under normal conditions. But due to the increasement of air pollutants, much of the radiation that normaly would be reflected to space, stay at the atmosphere, heating earth more and more.

By: Sandy Gomes

Whale

The whale is an endangered animal. She can be easily recognized by it’s big rectangular head, that equals to 40% of it’s total length. It’s color is normaly grey but it can also be brown, in rare cases. The average weight of these animals is about 45 tones in the males and 20 tones in the females. They feed out of fish, octopuses and squich. It is endangered because of it’s rare and expensive products, like ambar-gris.

By: Sandy Gomes

Greenhouse Effect

Is called greenhouse effect to the absorption of infrared emissions by the atmosphere, stopping the same emissions to escape to outer space.
The greenhouse effect is a natural characteristic of earth’s atmosphere and without this effect, the temperature that we are used to would be much lower. The current inbalance happens because this effect is gradually increasing.
The main gases that cause the greenhouse effects are carbon dioxide (CO2), methane (CH4), mitrous oxide (N2O) and CFC’s (chlorofluorocarbons). Nowadays, these gases concentrations are increasing mortally because of it’s liberation through industries, transportations and deforestation.
By: Sandy Gomes

Ozone

In the upper layers of the atmosphere, the ozone acts like a protector shield, absorving the UV rays that come from the sun.
However, the ozone is easily destroyed by gases as CFC’s, halogenated compounds, carbon tetrachloride, methyl bromide, HCFC’s and HBFC’s, that are emitted by activities related to industry.


By: Sandy Gomes

Air Pollution

"Two million people a year killed by air pollution, says WHO"

http://www.naturalnews.com/020666.html

According to a new study of the WHO (World Health Organization), air pollution causes roughly 2 milion premature deaths each year.

Air pollution is of the most known forms of pollution, since the problems that are caused by it are very grave and actual, such as respiratory diseases.
Air pollution comes in many types, like, for instance, smog, which results from the mixture of smoke and sulfur dioxide; acid rain, which comes from the reaction of primary air pollutants, primarily sulfur oxides and nitrogen oxides; temperature inversions and soil contamination.

The sources of this pollution are:

- Power plants, manufacturing facilities or municipal waste incinerators;

- Motor vehicles;

- Marine vessels;

- Burning wood;

- Waste deposition in landfills, which generate Methane, a non-toxic but flammable gas.

It is to our best interests that we protect our community from these sources.

Leonardo Campos

Light Pollution

"Our desire for night-time lighting in a 24-hour society seemingly justifies any amount of wasted light"

I stumbled across an interesting article regarding light pollution. (http://news.bbc.co.uk/2/hi/science/nature/4794249.stm)

This article enlightens most of the causes and consequences of wasting light.
Altough light pollution is ignored by many many people, it is a problem as grave as water pollution or air pollution. Not just to our health, but to our pockets as well. Every year millions of dollars are wasted in light pollution, which has no purpose whatsoever. Even the most modern streetlights shine directly into the sky, and serve no purpose.
Salesmen don't help either, since most stores sell bulbs from 150 to 500 Watts. A 5-watt bulb used in lighthouses can be visible for more than 21 miles.
It is everyone's job to prevent this, even if just by turning down the lights in our houses, or buying new bulbs with less wattage.

Leonardo Campos