The Possibility of a New Ice

Some researchers have even proposed that the effects of global warming could trigger a major climate change that could suddenly plunge the world back into another ice age rather than the warming period predicted by the IPCC. At the center of this theory is the Gulf Stream—a strong ocean current that transports warm water from the tropics to northwestern Europe, giving it a temperate climate similar to that of the United States even though it is located at a much higher latitude, more like the location of Alaska. The Gulf Stream is driven mostly by differences in water temperature and salinity: Warmer waters from the tropics evaporate and are cooled as they head north, and these salty, cool waters then settle to the bottom of the sea, where they form a massive undersea river that flows south down to the Southern, Antarctic Ocean. The process then repeats, creating what has been referred to as a conveyor belt in the ocean that helps regulate temperatures between the Northern and Southern Hemispheres.

According to researchers, however, melting polar ice caps and the melting glaciers in Greenland caused by global warming will add huge amounts of freshwater to the northern Atlantic Ocean, and this freshwater could disrupt the Gulf Stream conveyor pro-

The Gulf Stream cuts a path through the Atlantic Ocean off the coast of Newfoundland, Canada, as seen from space.

The Gulf Stream cuts a path through the Atlantic Ocean off the coast of Newfoundland, Canada, as seen from space.

cess because it will not sink like salty water. Such a slowing or shutting down of the Gulf Stream, some scientists speculate, could cause a rapid cooling of temperatures within a few decades, possibly causing a little ice age like the one that occurred a few centuries ago and contributing to harsher winters, droughts, and crop failures in some countries. The worst-case scenario is that the world could return to a full-blown ice age, a prospect that could challenge the ability of humans to survive around the globe.

Scientists once believed that such a major climate shift could only occur gradually over hundreds of years. However, newly developed drilling equipment has allowed scientists in recent years to extract and examine ice cores from some of Greenland's most ancient glaciers. Thanks to this new technology, scientists were able to look at individual years of snow. What they learned is that the Earth has often transitioned from ice-age weather to temperate weather like that of today in a matter of just two to three years. The shocking news is that instead of a slow change in climate, the Earth is capable of making a major climate shift when it reaches a certain tipping point.

In fact, there is now evidence that the Gulf Stream may already be weakening due to global warming. A group of scientists in Britain have recently shown that the flow rate of the Atlantic current dropped significantly from 1957 to 1998, and in 2004 the Gulf Stream even came to a complete halt for ten days. Although the current has speeded up slightly since 2004, policy makers in Europe remain concerned because of the dramatic effect that such a change could have on Europe's climate. Indeed, scientists worry that a slowdown in the Gulf Stream could produce a temperature drop of 1.8 degrees Fahrenheit (1 degree Celsius) over the next decade in Britain, and a complete shutdown could lead to a 7.2- to 19.4-degree-Fahrenheit (4-to 6-degree-Celsius) cooling over twenty years. At this point, no one knows whether or not this data is a sign that the Gulf Stream is sputtering to a halt. As lead scientist Harry Bryden at the National Oceanography Centre in the United Kingdom said about the temporary stopping of the current: "We'd never seen anything like that before and we don't understand it. We didn't know it could happen."21

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Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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