Steve McIntyre seems to pour cold water on a study allegedly demonstrating global warming.
As you see, there is a persistent decline in the alkenone reconstruction in the 20th century using published dates, but a 20th century increase using Marcott-Shakun dates.
Changing the dates of observations? Even macroeconometricians do not try that one.
Isn’t that exactly what Valery Ramey was doing when trying to find the best dates to attribute stimulus preparation and spending to?
link?
The McIntyre quote is from
http://climateaudit.org/2013/03/16/the-marcott-shakun-dating-service/
For a good summary, see this guest post at climate scientist Judith Curry’s blog:
http://judithcurry.com/2013/03/19/playing-hockey-blowing-the-whistle/
Basically, the Science article gets a steep rise in the 20th century temperature (hockey stick) because they shifted a few proxy time series (in)conveniently in time.