Paola Moffa-Sánchez, Andreas Born, Ian R. Hall, David J. R. Thornalley, Stephen Barker. Solar forcing of North Atlantic surface temperature and salinity over the past millennium. Nature Geoscience, 2014; DOI: 10.1038/ngeo2094
There were several centennial-scale fluctuations in the climate and oceanography of the North Atlantic region over the past 1,000 years, including a period of relative cooling from about AD 1450 to 1850 known as the Little Ice Age1. These variations may be linked to changes in solar irradiance, amplified through feedbacks including the Atlantic meridional overturning circulation2. Changes in the return limb of the Atlantic meridional overturning circulation are reflected in water properties at the base of the mixed layer south of Iceland. Here we reconstruct thermocline temperature and salinity in this region from AD 818 to 1780 using paired δ18O and Mg/Ca ratio measurements of foraminifer shells from a subdecadally resolved marine sediment core. The reconstructed centennial-scale variations in hydrography correlate with variability in total solar irradiance. We find a similar correlation in a simulation of climate over the past 1,000 years. We infer that the hydrographic changes probably reflect variability in the strength of the subpolar gyre associated with changes in atmospheric circulation. Specifically, in the simulation, low solar irradiance promotes the development of frequent and persistent atmospheric blocking events, in which a quasi-stationary high-pressure system in the eastern North Atlantic modifies the flow of the westerly winds. We conclude that this process could have contributed to the consecutive cold winters documented in Europe during the Little Ice Age.
Click here for full paper (fee). More discussion of this paper can be found here.
I like this fellow. He is inspiring and understands the times.
“On Monday at The New York Meeting, Dr. Ben Carson said he does not believe in gun registration because America’s massive debt could transform the nation into a third-world country in which martial law may be imposed.’ click here
The word “sustainability” has intentionally been associated with “renewable energy” and purposely so, in order to “sell” renewables to the general public. I have no particular objection to renewable energy in general.
But I do object to limiting the definition of “sustainability” to only renewables. For infrastructure and energy sources to be “sustainable”, they must satisfy 3 demands. First, a “sustainable” technology is one that is economically sustainable. It must be self-supporting economically, and so far no renewable energy completely satisfies this requirement. A look at the government subsidies above should give you a clue that these technologies cannot sustain themselves over the long haul (certainly for now).
Second, a “sustainable” technology must be one that is societally sustainable. (If the culture and society do not accept it, it will not be sustainable. Attempting to force acceptance via laws and regulations inevitably fails.)
Third, it must be environmentally sustainable. Assuming for the purposes of discussion that CO2 should be controlled, how much CO2 is produced during the manufacture and installation of a solar panel? Or a wind turbine? How many birds are killed by wind turbines? Or concentrating solar panels? What toxic substances are produced during the production of solar panels and wind turbines? These and many other questions remain regarding the environmental sustainability of renewable energies.
I suspect that tying the idea of renewable energy rigidly to “sustainability” will eventually doom renewable energy on a large scale. Walmart must look for profit to stay afloat. Perhaps their investment in hydrogen fuel cells will pay off and perhaps it will not. Click here