[Sicon]

1998 was an El Nino year, and El Nino years are years with higher-than-average global warmth. The next year was a La Nina year, and it was colder. In the ensuing years, the global temperature anomaly has been between the 1998 record and the 1999 subsequent minimum, and (with variability), the years have gotten warmer -- to the point that 2005 was almost as warm (some analyses indicate "as warm") as 1998, without an El Nino event. This last datum indicates that the warming trend is still ongoing.

So... based on a whole 7 years worth of "data", you actually feel comfortable in suggesting that this represents a significant "warming trend", and even further, that human activity is somehow responsible?

[cogitator]

So... based on a whole 7 years worth of "data", you actually feel comfortable in suggesting that this represents a significant "warming trend", and even further, that human activity is somehow responsible?

No, that's certainly not all. The warming trend that climate scientists are most concerned about, the one that is seen as the salient indicator of human effects on climate, is the one that started in the mid-1980s. Because of a slight cooling mid-century, the full global warming increase in the 20th century was 0.6 C. Since the mid-1980s, the global temperature has increased about 0.4 C. I believe that six of the 10 warmest years in the 20th century were in the 1990s. All of this (and more) is seen as the human effect "signal" emerging from the climate variability "noise".