Standardized Greenland (GISP2) ice-core volcanic sulfate (Zielinski et al., Science 264, 948 (1994) Year Volcanic Sulfate 1990 1985 1980 7.86 1975 -0.09 1970 56.60 1965 -0.39 1960 -7.49 1955 2.35 1950 -5.43 1945 -3.21 1940 -13.22 1935 -12.54 1930 -6.91 1925 17.10 1920 7.52 1915 24.95 1910 15.90 1905 13.58 1900 -12.30 1895 -6.67 1890 -1.92 1885 11.11 1880 0.75 1875 -3.25 1870 -2.23 1865 2.49 1860 3.39 1855 6.38 1850 -5.68 1845 5.22 1840 -4.35 1835 14.73 1830 25.37 1825 -1.81 1820 1.08 1815 45.95 1810 21.85 1805 -6.22 1800 -7.45 1795 1.52 1790 -0.92 1785 22.80 1780 33.26 1775 -2.02 1770 -2.93 1765 12.45 1760 3.05 1755 3.35 1750 -9.94 1745 -7.00 1740 11.48 1735 2.30 1730 14.03 1725 -1.69 1720 4.13 1715 -0.86 1710 -2.29 1705 -0.99 1700 2.85 1695 24.18 1690 -8.77 1685 -9.88 1680 -7.77 1675 5.19 1670 5.91 1665 10.07 1660 3.78 1655 -5.83 1650 -4.04 1645 9.77 1640 35.78 1635 4.91 1630 -1.90 1625 -2.42 1620 -1.60 1615 -3.71 1610 -5.35 1605 25.77 1600 9.95