I have a confession to make…it ain’t much fun to talk climate change at a time where AGW and especially Catastrophic AGW are taking blows left, right and center. So in order to keep this blog lukewarm, here’s a heartful “thanks!” to New Scientist for providing the context for planetary temperatures so far:
Around 500 million years of Earth temperature
And yes, our current climate WARMING catastrophe is at the bottom right.
We present reconstructions of Northern and Southern Hemisphere mean surface temperature over the past two millennia based on high-resolution ‘proxy’ temperature data which retain millennial-scale variability. These reconstructions indicate that late 20th century warmth is unprecedented for at least roughly the past two millennia for the Northern Hemisphere. Conclusions for the Southern Hemisphere and global mean temperature are limited by the sparseness of available proxy data in the Southern Hemisphere at present.
Reconstructions of hemispheric mean temperatures over roughly the past two millennia employing proxy surface temperature data networks with sufficient spatial and seasonal sampling, temporal resolution, and retention of millennial-scale variance, support previous conclusions with regard to the anomalous nature of late 20th century temperature at least about two millennia back in time for the Northern Hemisphere. To the extent that a ‘Medieval’ interval of moderately warmer conditions can be defined from about AD 800– 1400, any hemispheric warmth during that interval is dwarfed in magnitude by late 20th century warmth. The sparseness of the available proxy data in the Southern Hemisphere lead to less definitive conclusions for the SH or global mean temperature at present.
Take for example the recent mild UK weather. OF COURSE CO2 has nothing to do with it. Temperatures are higher than normal because southerlies bring warm air over from France. A proper analysis of October/November trends (and we did have quite a few very cold days already) would have to include a research on wind patterns.