The Goldilocks Planet
The four billion year story of earth's climate
Jan Zalasiewicz & Mark Williams, Central, 551.609 Z22G 2012
Skimmed.
I looked more closely at the discussion of the Maunder (sunspot) Minimum ( p220-223 ) and "The early Anthropocene hypothesis" ( p232-237 ). What evidence is available to estimate past climate, particularly temperature? And where and when? Calibrated thermometers did not appear until the 1750s, and systematic records until the 1850s in western Europe and the east-coast United States; a very small slice of time and space.
The Maunder Minimum from 1645 to 1715 correlates with the middle of the Little Ice Age starting in 1300 to 1550 (disagreement on labeling) and ending around 1850.
The book claims (p221) that increased sunspot activity strengthens the earth's magnetic shield (huh?) which blocks cosmic rays. Cosmic rays can nucleate water droplets and make clouds ... no sunspots, more clouds.
- Or ... more clouds, fewer opportunities to observe and record sunspots?
Ruddiman, W.F. 2003 The anthropogenic Greenhouse Era began thousands of years ago. Climate Change 61, 261-293.
Ruddiman, W.F. 2007 The early anthropogenic hypothesis: challenges and responses. Reviews of Geophysics 45, RG4001, 1-37.
Ruddiman and Ellis, E.C. 2009 Effect of per-capita land-use changes on Holocene forest cleance and CO2 emissions. Quaternary Science Reviews 28, 3011-15.
Stocker, T. (2009) Making the paper. Nature 461, 446.