March 25, 1994


Man is a creature fit for any climate, and necessity and determination soon reconcile him to anything.

Ferdinand Wrangell, Polar explorer, 1840

If you read about science in the textbooks, you are left with the impression that science progresses because one great scientist has a great idea, and then every other scientist just jumps on the bandwagon and science moves forward. Certainly brilliant scientists are important, but that is only part of the story. Galileo wouldn't have discovered the moons of Jupiter if someone else hadn't invented the telescope.

Climatology is hot at the moment, particularly paleoclimatology, the study of climate in the distant past. We now have computers and satellites that can observe the earth and the sun and take their temperatures. Thanks to the people who supply the oil industry, there are drilling rigs that can go very deep and remove cores of rock or ice. Thanks to an interest in the environment, particularly in the area of global warming, there is money available -yes, you can't buy or run one of those drilling rigs without big bucks.

So now climatology is where genetics was at the turn of the century. It is attracting bright young people and for good reason. Groups of scientists and engineers are drilling holes in the mile thick ice sheets in the arctic, antarctic and Greenland. New clever methods to analyze infinitesimal amounts of chemicals and the analysis of isotopes of oxygen and other elements permit people to take these ice core samples and have some idea how warm or cold it was when the snow fell that made the ice. They can also detect volcanic ash that tells of large volcanic eruptions. Who knows what exciting findings those ice cores will yield?

Anyone who thinks that climate is simply a matter of carbon dioxide and the greenhouse affect doesn't know much about the subject. A few year ago we had an exceptionally hot summer and some people were saying "see, we are getting global warming." The next year Mt. Pinatubo blew its top and dumped some 20,000,000 tons of sulfur dioxide into the upper atmosphere and the global temperature went down 0.25¤C. This year the East and Midwest got rains and cold, but we in California have had a relatively mild winter and the southland got a lot of rain. Weather is a complicated business and climate is even more complicated. There is little question that the activities of Homo sap. will be important, but it is only part of the picture, even though people tend to think that we are the only things of importance in the the universe. We also tend to think that nothing really important happened before we were born.

In New York, where I grew up, I could see the effects of the great glacier on the ground. Great boulders were scraped along and eventually deposited on the ground by the ice sheet that once covered much of North America. The experts tell us that we are now in the Holocene interglacial period, a period of warm temperatures that started about 10,000 years ago. For the 100,000 years before that it was glacial. Before that there was another period of warming, more great glaciers, and another warm time.

Scientist just love to find cycles and there are lots of cycles that may influence climate. Variations in the position of the earth's axis relative to the sun yield different cycles of 23,000, 41,000 and 100,000 years. The 11 year sunspot cycle affects climate and weather. Geologic factors such as the rise of mountains can have a profound affect, particularly on local climate. Volcanic dust can have a profound affect. The impact of asteroids or meteors can produce major worldwide changes in temperature. Ocean currents and salt concentration, which we are just beginning to understand, can have large affects on weather and climate.

It is worth considering that marvelous as these ice core projects are, they are infinitesimally small samples of a special part of a large and complicated world. They are, nevertheless, a giant step in our understanding of climate.

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