Part 136 (1/2)

169 theories for why global warming is causing a s.h.i.+ft in the Hadley cells

Lu et al., ”Expansion of the Hadley Cell Under Global Warming.”

170 the difference in average temperatures

Jennifer Francis and Stephen Vavrus, ”Evidence Linking Arctic Amplification to Extreme Weather in Mid-Lat.i.tudes,” Geophysical Research Letters 39 (2012).

171 The widening of the Hadley cells

Lu et al., ”Expansion of the Hadley Cell Under Global Warming.”

172 on the edge of persistent water shortages anyway

Personal communication with Dargan Frierson, May 25, 2012.

173 human alteration of the same natural climate feature

Rudolph Kuper and Stefan Kropelin, ”Climate-Controlled Holocene Occupation in the Sahara: Motor of Africa's Evolution,” Science, August 11, 2006.

174 barrel loop atmospheric currents known as the Ferrel cells

National Oceanic and Atmospheric Administration, ”JetStream-Online School for Weather,” October 2011,