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אפקט החממה

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סיכום באנגלית על אפקט החממה וההתחממות העולמית

GLOBAL WARMING

Global warming may seem like an abstract problem: some day, the earth will warm, the
oceans will rise and the weather will change. But each one of us will feel global warming's
effects, if in different ways. It will hit us all where we live. The earth, over millions of years of
development and evolution, has balanced out all ecosystems and relations. This balance is now,
however, threatened by rising temperatures and emission of certain gasses. Heat-trapping gases
come from power plants and vehicles. Modern technologies and stronger laws can contribute to
their reduction.
It's not just about shorts and sandals. Global warming means more air pollution and
problems with water supplies as precipitation patterns change, as well as huge threats to
ecosystems from the Everglades to the glaciers. There will be hotter, longer heat waves and more
intense storm systems. Forests, farms and cities will face troublesome new pests and more
mosquito-borne diseases. Scientists say many of these symptoms are already appearing.
The ozone layer protects earth from absorbing dangerous radiations. Gasses like Methane,
CFC, and complex compounds that contain CO2 are constantly destroying it. This has many
consequences. Firstly, earth absorbs radiation that destroys life and threatens the existence of
many creatures. It is also affecting the efficiency of photosynthesis, which cleans and refreshes
CO2 compounds. Direct radiation also causes glaciers to melt, causing electromagnetic
imbalance at the poles, less ice to act as a “fridge”, endangers the balances of food chains that
involve water-land relations, and raises sea level. These higher temperatures threaten dangerous
consequences: drought, disease, floods, lost ecosystems. And from sweltering heat to rising seas,
global warming's effects have already begun.
Humans are the dominant force behind the sharp global warming trend seen in the 20th
century, according to this analysis of the climate over the last 1,000 years. The report found that
natural factors like volcanic eruptions and fluctuations in sunshine, which were powerful
influences on temperatures in past centuries, can account for only 25 percent of the warming
since 1900. Human activity, particularly rising levels of carbon dioxide and other heat-trapping
gasses caused the rest of the warming.
Extreme weather events such as droughts, floods, heat waves and heavy rainfall are
expected to increase over the next 100 years, according to a team of scientists from the National
Climatic Data Center. It is believed that as levels of green house gases (GHGs) in the atmosphere
raise, wild and extreme climate phenomena will increase. That increase will cause, for example,
alpine meadows in the Rocky Mountains to disappear, sugar maple trees to vanish in the
Northeast, and greater risk from storm surges in the Southeast. Rising temperatures will also
exacerbate water shortages and cause New York City to steam in the summer, sea levels to rise,
ocean heat content to increase, and snow cover and ice extent to decrease.
Rising temperatures caused by the burning of fossil fuels could cause large-scale and
irreversible climate changes. Those changes include altered ocean currents, slowed circulation of
warm water in the North Atlantic and a vast reduction of mountain glaciers and the Greenland
ice sheet. Poor countries, particularly those in Latin America, Africa and Asia would bear most of
the burden of extreme climate changes, which would further widen the gap between poor
nations and rich ones.
Scientists say the dramatic disintegration of an ice chunk off the Antarctic Peninsula earlier
this year is most likely the result of global warming. "With the disappearance of ice shelves that
have existed for thousands of years, you rather rapidly run out of other explanations," Dr.
Theodore A. Scambos, a glaciologist at the National Snow and Ice Data Center, told The New
York Times after the Larsen B shelf collapsed. Scambos and other researchers said it was the first
time in thousands of years that the east coast of Antarctica had seen such sharp rises in
temperature and dramatic ice loss. Over the last 50 years, average temperatures in the Antarctica
Peninsula raised by 2.5 degrees Celsius, four times the global average. The unprecedented
warming has led to a pattern of ice shelve loss on the eastern side of the Peninsula not seen in
12,000 years, researchers said. Scientists said they were also shocked by the speed with which the
Larsen B shelf disintegrated -- 1,200 square miles (3,000 square kilometers) in 35 days.
Global warming may also have a devastating effect on economy and industry. Farmers
would face a 35 percent (average) drop in all yields because of warmer temperatures. This
discovery might also mean a shortage in food, and yet, another imbalance to ecosystems.
A study found that habitat loss for individual species due to global warming could be as
high as 17 percent by 2030, 34 percent by 2060 and 42 percent by 2090 -- if emissions of heat-
trapping pollution such as carbon dioxide are not reduced.
In order to improve the situation, a vast change is necessary. On the personal level,
reducing energy consumption, driving efficient cars and driving less, using “green” products.
Raising conciseness to the problem. But all those are not substantial enough to cause rapid
change. Governments should enforce and rule in favor of global warming related discoveries,
and should fine businesses who shall not do all they can to help the environment rather than
harm it. The governments should support studies and complete projects that will reduce pollution
(such as solar energy, microwave replacements, etc.) and should take responsibility and fund
projects and pro-environment education.


BIBLIOGRAPHY


http://www.nrdc.org/globalwarming/
http://www.worldviewofglobalwarming.org/
http://yosemite.epa.gov/oar/globalwarming.nsf/content/index.html
http://www.climatehotmap.org/
http://www.ngdc.noaa.gov/paleo/globalwarming/home.html
http://www4.nas.edu/onpi/webextra.nsf/web/climate?OpenDocument
http://www.sierraclub.org/globalwarming/

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