Elements of Weather
5. No, plate tectonics cannot explain short-term changes because the rate of plate movement is very slow. The climatic changes brought about by continental drift are very gradual and happen on a scale of millions of years.
6. The major influences of these eruptions upon climate was a cooling effect produced by a slight increase in the earth's albedo. This albedo change resulted from the large quantities of sulfur dioxide emitted and the aerosol particles formed from this gas. Reaching the stratosphere where it persisted for some time, this aerosol increased the earth's albedo, reducing the amount of solar radiation absorbed by the earth.
7. The massive explosive eruption of the Indonesian volcano, Mt. Tambora.
8. Variations in the shape of the earth's orbit (which occur on a cycle of from 90-100 thousand years) cause variations in the difference between aphelion and perihelion, which, in turn, causes variations in the amount of solar energy received at those times. Changes in the angle that the earth's axis makes with the plane of its orbit cause variations in seasonal temperature contrasts. As in the case with the preceding variable, the wobbling of the earth's axis over a period of about 26,000 years results in variations in seasonal temperature contrasts.
9. Recent studies tend to confirm the Milankovitch cycles and predict an impending ice age.
10. One possible connection links cold periods in Europe and North America to times when sunspots were absent or nearly so and warmer periods to times when sunspots were plentiful. A second proposed sun-climate connection suggests that droughts in the western United States are linked to the 22-year sunspot cycle. These possible relationships are not widely accepted because, despite much research, no connection between solar variations and weather has ever been unequivocally established.