Because of changes in the global climate since 1850 AD that have occurred from

Because of changes in the global climate since 1850

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Because of changes in the global climate since 1850 AD that have occurred from human activity, we humans are creating the conditions that undermine our very existence and could lead to our extinction as a species as happened to the dinosaurs.
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Abrupt Climate Change Complex systems, like the atmosphere, are known to move from one steady state to another, with only brief transitions in between. Ice cores from Greenland taken in the 1990s show that the last ice age came to an end, not in the slow creep of geological time, but in the quick pop of real time . The entire planet abruptly warmed in just three years. (Richard Alley of Penn State) Change can come when a threshold has been crossed. Climate often seems like its controlled by a dial, but occasionally it acts as if its controlled by a switch . The switch clicks, initiating abrupt change in climate . Growing accumulation of geological evidence is making it ever clearer that in the past climate has undergone drastic changes in temperature and rainfall patterns in the space of a human lifetime. Climate change has sometimes occurred in a decade or in even less time .
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Evidence When Greenland began its ascent out of the last ice age more than 11,000 years ago, temperatures there spiked upward by about 9 to 18 degrees Fahrenheit in at most mere decades and probably in less than a single decade . (Study by Dr. Jeffrey Severinghaus of the University of Rhode Island from Greenland ice core samples.) Other records show extreme temperature swings, exceeding 11 0 F (6 0 C) within 50 years in some cases. Study of ocean sediments off subtropical North America. This study showed climate changes that scientists thought should take thousands of years to occur actually occurred in a generation or two at most . These changes wreaked havoc on civilizations in Africa and the Middle East.
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Example of How a Threshold Event Could Occur Warmer temperatures could produce more precipitation and melt more snow and ice in Arctic areas. This could flood with fresh water the critical Gulf Stream/North Atlantic Drift that transports heat to the North Atlantic. This will dilute the salt content on which the current’s function depends. The Gulf Stream/North Atlantic Drift would be weakened or possibly halted, making Europe much colder than today . The Gulf Stream/North Atlantic Drift could shut down completely if atmospheric concentrations of CO 2 double within the next 100 years. (Research article from the journal Nature )
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What is climate? Climate – the sum of the weather events that could occur at a location. This includes the average weather pattern at a location, but also includes the extreme events that are statistically possible at that location (tornadoes, hurricanes, big winter snow storms, and so forth.) Climate averages all the warm, cold, wet, and dry observations at a location to come up with what is considered “normal” for the area at a specific time of the year.
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