(Part of the How to Talk to a Global Warming Skeptic guide)
Objection: Global temperatures have been trending down since 1998. Global warming is over.
Answer: At the time, 1998 was a record high year in both the CRU and the NASA GISS analyses. In fact, it blew away the previous record by .2 degrees C. (That previous record went all the way back to 1997, by the way!)
According to NASA, it was elevated far above the trend line because 1998 was the year of the strongest El Nino of the century. Choosing that year as a starting point is a classic cherry pick and demonstrates why it is necessary to remove chaotic year-to year-variability (aka: weather) by smoothing out the data. Looking at CRU's graph below, you can see the result of that smoothing in black.
![](http://gristmill.grist.org/images/user/6932/cru_2005.gif)