"Surface temperatures have shown small but steady increases since the 1970s, but the tropics had shown little atmospheric heating — and even some cooling. Now, after sleuthing reported in three papers released by the journal Science, revisions have been made to that atmospheric data."  

 http://www.usatoday.com/tech/science/2005-08-11-global-warming-data_x.htm 

 By not including the source and revision of the data which the petition was based on your saying all the people who signed it were lying.  The reader needs to understand they were looking at what at the time they though was valid data but has since been proven by "three papers released by the journal Science" to be invalid. 

 You can just say it wasn't true.  We might know today that it wasn't true but they didn't at the time. 

  Thu Aug 25 17:13:12 EDT 2005