Mann: Trees aren’t behaving like I want them to – volcanoes to blame | Watts Up With That?

“We know these tree rings capture most temperature changes quite well,” said Michael Mann, professor of meteorology and geosciences and director of the Penn State Earth System Science Center. “But the problem appears to be in their response to the intense short-term cooling that occurs following a very large volcanic eruption. Explosive volcanic eruptions place particulates called aerosols into the stratosphere, reflecting back some fraction of incoming sunlight and cooling the planet for several years following the eruption.”

 Tree rings are used as proxies for climate because trees create unique rings each year that often reflect the weather conditions that influenced the growing season that year. For reconstructing climate conditions, tree-ring researchers seek trees growing at the extremes of their growth range. Inferring temperature changes required going to locations either at the tree line caused by elevation or at the boreal tree line, the northern most place where the trees will grow.

For these trees, growth is almost entirely controlled by temperature, rather than precipitation, soil nutrients or sunlight, yielding a good proxy record of surface temperature changes.

EU Referendum: Not what it seems

our Melanie lays into the coalition. In Gulliver's Travels, she writes, Jonathan Swift mocked scientists by inventing a satirical wheeze for extracting sunbeams out of cucumbers. If Swift were alive today, he'd be out of a job, for the Coalition’s green policies are simply beyond satire.

A testable prediction by a nutter : Stoat

Habibullo I. Abdussamatov of the Pulkovo Observatory of the RAS thinks solar irradiance is in for a "bicentennial decrease". And has been kind enough to predict it. Unfortunately it won't be obvious until about, what, 2016, that he is hopelessly wrong. But it beats most of the nutters who just wurble and nitpick and never predict anything.

- Bishop Hill blog - Pathological mendacity

A few months back, Steve McIntyre said something that stuck in my memory:

Never under-estimate the capacity for institutional mendacity.

Today he writes in similar vein about the extraordinary range of mutually inconsistent stories put forward by the University of East Anglia in its various pronouncements on the availability of the CRU emails. Institutional mendacity indeed.

Acton “Tricks” the ICO « Climate Audit

The Wahl-Briffa correspondence contains many marks of furtiveness, due, in my opinion, to the fact that the AR4 document was now in its final stages and Wahl, who was not an IPCC contributing author or even reviewer, was now both editing the language of the final AR4 document and the responses to reviewers on an issue in which he was a disputant. The emails were all headed “confidential”, with the word “confidential” recurring in the emails.