Changes

==Past speculation==  

==Past speculation==  

Speculation and warnings of catastrophic climate change are not unprecedented. In 1971 the journal Science reported that the subsequent cooling effect resulting a possible eightfold increased from atmospheric aerosol concentrations , "if sustained over a period of several years - is believed to be sufficient to trigger an ice age."  In 2001 the Guardian noted that some 70s headlines shouted, "Brace yourself for another ice age." <ref>Reported by Alison George in ''Breaking the ice'', The Guardian, Thursday 28 June 2001</ref>

Speculation and warnings of catastrophic climate change are not unprecedented. In 1971 the journal ''Science'' reported that the subsequent cooling effect resulting a possible eightfold increased from atmospheric aerosol concentrations , "if sustained over a period of several years - is believed to be sufficient to trigger an ice age."  In 2001 the ''Guardian'' noted that some 70s headlines shouted, "Brace yourself for another ice age." <ref>Reported by Alison George in ''Breaking the ice'', The Guardian, Thursday 28 June 2001</ref>

In June, 1974, [[Time]] magazine published ''Science: Another Ice Age?''<ref>''Science: Another Ice Age?'' Time magazine, Monday, Jun. 24, 1974</ref>  A report by the [[CIA]] in the same year stated that, "The world's leading climatologists have confirmed recent reports of a detrimental global climatic change”, noting such things as that the "world's snow and ice cover had increased by at least 10 to 15 percent", and "the Canadian area of [[Arctic]] Greenland suffered below normal temperatures for 19 conservative months", which was unique during the last 100 years.  A "major climatic shift" was speculated, which would threaten the "the stability of most nations.” It further warned that "Scientists are confident that unless man is able to modify the climate, the  northern regions, such as Canada" to "major areas in northern China will again be covered with 100 to 200 feet of ice and snow", within the next 2500 years - or sooner.<ref>[http://www.climatemonitor.it/wp-content/uploads/2009/12/1974.pdf ''A study of climatological research as it pertains to intelligence problems'', August 1974]</ref>  

In June, 1974, ''[[Time]]'' magazine published ''Science: Another Ice Age?''<ref>''Science: Another Ice Age?'' Time magazine, Monday, Jun. 24, 1974</ref>  A report by the [[CIA]] in the same year stated that, "The world's leading climatologists have confirmed recent reports of a detrimental global climatic change”, noting such things as that the "world's snow and ice cover had increased by at least 10 to 15 percent", and "the Canadian area of [[Arctic]] Greenland suffered below normal temperatures for 19 conservative months", which was unique during the last 100 years.  A "major climatic shift" was speculated, which would threaten the "the stability of most nations.” It further warned that "Scientists are confident that unless man is able to modify the climate, the  northern regions, such as Canada" to "major areas in northern China will again be covered with 100 to 200 feet of ice and snow", within the next 2500 years - or sooner.<ref>[http://www.climatemonitor.it/wp-content/uploads/2009/12/1974.pdf ''A study of climatological research as it pertains to intelligence problems'', August 1974]</ref>  

Also in 1974, Nigel Calder, former editor of New Scientist and atmospheric researcher wrote in his book ''The Weather Machine'', "One might argue that there is a virtual certainty of the next ice age starting some time in the next 2000 years. Then the odds are only about 20-to-1 against it beginning in the next 100 years."  

Also in 1974, Nigel Calder, former editor of ''New Scientist'' and atmospheric researcher wrote in his book ''The Weather Machine'', "One might argue that there is a virtual certainty of the next ice age starting some time in the next 2000 years. Then the odds are only about 20-to-1 against it beginning in the next 100 years."  

In 1975 the liberal [[Newsweek]] magazine reported that "Meteorologists disagree about the cause and extent of the cooling trend,...but they are almost unanimous in the view that the trend will reduce agricultural productivity for the rest of the century." These authorities were skeptical that political leaders would take any positive action to compensate for the [[climate change]], though they conceded that the more dramatic solutions, such as melting the arctic ice cape, might create worse problems than that which they were designed to solve.<ref>http://denisdutton.com/newsweek_coolingworld.pdf</ref>

In 1975 the liberal magazine ''[[Newsweek]]'' reported that "Meteorologists disagree about the cause and extent of the cooling trend,...but they are almost unanimous in the view that the trend will reduce agricultural productivity for the rest of the century." These authorities were skeptical that political leaders would take any positive action to compensate for the [[climate change]], though they conceded that the more dramatic solutions, such as melting the arctic ice cape, might create worse problems than that which they were designed to solve.<ref>http://denisdutton.com/newsweek_coolingworld.pdf</ref>

==Natural Variability of the Climate System==

==Natural Variability of the Climate System==