Monday, December 22, 2014

Long Term Global Cooling

Anthony Watts of website WattsUpWithThat reports on a study in the Journal of Quaternary Science (2014) as follows:
Esper et al. (2014) write that tree-ring chronologies of maximum late wood density (MXD) “are most suitable to reconstruct annually resolved summer temperature variations of the late Holocene.” And working with what they call “the world’s two longest MXD-based climate reconstructions” – those of Melvin et al. (2013) and Esper et al. (2012) – they combined portions of each to produce a new-and-improved summer temperature history for northern Europe that stretches all the way “from 17 BC to the present.”

This history depicts “a long-term cooling trend of -0.30°C per 1,000 years over the Common Era in northern Europe.” (see the graph at Watts' article) Most important of all, (snip) “conditions during Medieval and Roman times were probably warmer than in the late 20th century,” when the previously-rising post-Little Ice Age mean global air temperature hit a ceiling of sorts above which it has yet to penetrate.

And so we continue to collect ever more real-world evidence for the fact, that there is nothing unusual, unnatural or unprecedented about the Earth’s current level of warmth.
You really need to see the graph upon which the longterm trend line has a definite downward slope. Hat tip to John Hinderaker at Power Line for the link.