More than one reader has taken issue with the wording Drew Thornley’s post of last week, scil.: “New data from all four of the major global temperature tracking outlets show that world temperatures last year dropped between 0.65 and 0.75 degrees Celsius. That’s the largest one-year temperature change ever recorded – up or down – and is large enough to wipe out virtually an entire century of warming. [emphasis added]Writes one:

“Global warming” is a statistical trend, based on data collected over a number of years; last year’s numbers are just a data point reflecting one year’s measurements — one new data point to be added to a hundred!
Last year’s temp decline will alter downwards the linear “best fit” slope of the warming trend the past hundred years. It might even be an inflection point.
But it’s too soon to tell. What if next year’s results are 0.75 degrees Celsius higher? And what if, looking back, there was a year with an temperature increase 80 percent as large as last year’s decrease? It would largely cancel out this year’s decrease. One year’s data doesn’t “wipe out” a century’s average.
Anthropogenic global warming zealots will jump on this as evidence of bad faith, not just sloppy math. Let’s not give them the ammunition.

Fair enough. It’s worth a clarification, which Drew Thornley has provided. And it doesn’t diminish the fact that 2007′s cooling is a blow to climate alarmists’ public narrative.