Semantic shift can occur in a variety ways. One way is called pejoration where a word with a neutral or positive meaning becomes associated with a negative sense. The opposite of this process, amelioration, is when a word acquires a positive meaning when originally that word was negative. I'll provide two illustrations.
For pejoration, consider the word fair. Originally, this word connoted beauty and/or respectability. Ever heard "My fair lady?" But today, the word fair is used to express mediocrity or something that is middle of the road. For instance, if a kid brought home a report card with a lot of Cs on it, the parent might say that it was a "fair" report card, meaning "OK." Fair is also used to indicate impartiality. As far as amelioration, consider what has happened to the derogatory term, "bitch", for women. It has now become a positive term, in some circles.
What is the point of this? Genuine semantic shift in langauge happens organically; it's not just something that occurs. Groups may come together and develop their own "Secret language" but that has no bearing on the rest of the world. Remember when President Clinton in his deposition before the Grand Jury went to great lengths to change the meaning of the word "is." I've always taught my students that the linking verb "to be" should be regarded as an equal sign (=). Bill Clinton thought otherwise.
Well, this past week, a hacker got into files at the University of East Anglia (UEA) which has a research facility devoted exclusively to studying the phenomenon of global warning. UEA has also been at the front lines to provide the scientific evidence of global warning which would then be used to justify various types of legislation to stop the culmination of greenhouse gasses which, supposedly, warm the earth in an unnatural way because man is the cause. The emails and other information downloaded by the hacker were then spread throughout the world. One of the emails between a professor at UEA and another at the University of Pennsylvania had this interesting tidbit:
Among his e-mails, Mr. Jones talked to Mr. Mann about the "trick of adding in the real temps to each series ... to hide the decline [in temperature]."
Now, if anyone were to read this, one would see the word "trick" and come to the conclusion that there is deceit at work, that there is some malfeasance going on with the reporting of certain climate data. And that is a resaonable conclusion.
However, Mr. Mann says to the New York Times that the word trick means something in scientific circles. He says:
scientists often used the word 'trick' to refer to a good way to solve a problem 'and not something secret.'
Again, semantic shift must happen organically and over time. Now, he does not say that such a definition is being used by society at large (I've never heard trick being used in a positive sense in regular conversation) but that this is a jargon that is located exclusively in the scientific community. I'm very curious to see how widespread the term "trick" is used in this exact manner amongst members of the scientific community. But, I'm willing to bet that it is not used this way at all.
The hoax that is globabl warming has been dealt a very serious blow and now the only way that the defenders of this hoax can continue to justify it is based solely on changing the definition of words. Unfortunately, many of the same people who are teaching this hoax that is global warming are also the same type of people who are teaching languages to our kids. Soon, no one will mean what they say. That's chaos.