Monday 22 April 2013

The warmest since last time

While mainstream media have failed to broadcast the news that global temperatures have flatlined in the last 15 years, calling into question the models that say they should have risen catastrophically, Government Radio this morning was trumpeting a new worldwide study indicating “the end of last century produced the hottest temperatures for 14-hundred years.”

The study shows [says RNZ] that the rise in the average temperatures reverses more than a millennium of gradual cooling.

But does it really show that?

The chart above shows the study’s thirty-year mean relative temperatures for the last 2000 years, based on proxy measurements derived from the study of proxies like tree rings, coral and pollen. The important point for warmists is that the Medieval Warm Period (in which agriculture flourished in places like Greenland) has been made to disappear, and it’s mostly red at the end—which is what is leading to the headlines.

Unfortunately for the trumpeted conclusion, which is the only thing about the study mainstream media will want to talk about, many of the data series chosen for the study appear to have been either selected because they fit that conclusion (“if the selection is done on the proxies without de-trending ie the full proxy records over the 20th century, then records with strong trends will be selected and that will effectively force a hockey stick result” says an email between the authors), weighted to fit the chosen conclusion, or if their 20th century record fails to match the narrative, they’ve just been truncated.

More here at Climate Audit, in both post and comments.

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