Sulfate in Greenland Ice Peaked During the Time of Greatest Global Warming
Volcanic sulphate per century (black) is unusually high during periods of rapid warming (red), suggesting major periods of volcanism are contemporaneous with global warming. Volcanic sulphate ranges from 0 to 2028 ppb. “Volcanic” sulphate during the 20th century was caused primarily by anthropogenic emissions from northern Russia, northern Europe, and central North America (Barrie et al., 1981) (Ward, 2009). The most recent value of volcanic sulfate per century shown (1910 ppb) is twice the sum observed during the 50 years from 1935 through 1984.Volcanic sulfate data are from Zielinski et al. (1996) (Data, Volcanic markers).
The isotopic content of ice expressed as a ratio δ18O = 18O/16O is a proxy for regional Greenland temperatures (Fisher et al., 1996). The total change in temperature in Greenland may have been in the range of 8 to 15oC (Huber et al., 2006) or around 16oC (Lang, 1999). The increase in equatorial Pacific sea surface temperature since the last glacial maximum is approximately 2.8oC (Lea, 2000). δ18O data are from (White et al., 1997) (Data, Stacked).