| What was the weather
like in the Incan land of Tuyantunsuyu (present-day Peru, Bolivia, and Ecuador)
in the year 1503 A. D.? Did moderate rains bring harvests of plenty, filling
the ruler's granaries and the people's stomachs, or did the skies open up
with fury, flooding the countryside and destroying the crops upon which
this vast empire depended? Since the dawn of human existence, the rhythms
of human societies like Tuyantunsuyu have been intimately linked to the
rhythms of nature. Aside from the daily cycle of light and dark and the
seasonal change from summer to winter, the most important natural rhythm
Climate (the statistical or average expression of daily weather events)
dictates when the first killing frost arrives, how long the growing season
will last, the quantity and location of game animals, the severity of winter
livestock kills, the productivity of coastal fisheries. In short, climate
throughout most of history has determined when every group of human beings
from farmers to fishermen to hunters would suffer and when they would prosper.
As we approach the 21st century, human societies are once again realizing
the vital role that climate plays in our daily lives.
Turn your attention (and your imagination) to Australia in 1807 A. D.
Both the aboriginal inhabitants of the continent and the newly arrived
European settlers worry and wonder whether this will be a year marked
by drought and fire, or one blessed by life-giving rains. Their fate,
like that of the Incas thousands of miles and hundreds of years from them,
was tied to the variations of a climatic system whose mysteries scientists
are only beginning to understand, the El Niño/Southern
Oscillation (ENSO for short).
Many scientists believe that studying the past behavior of ENSO is the key to understanding how it will act in the future. These people call themselves paleoclimatologists and their goal is to gather
as much information as possible about past climates. You are about to learn how paleoclimatologists use innovative techniques to unlock the door to new understandings of the ways in which the tropical climate system works. Surprisingly enough, their
most powerful tools, tools that can potentially tell us what the climate was like in Peru in 1503 or Australia in 1837, are the beautiful coral reefs like this that dot Earth's tropical oceans.
Department of Biology, University of Houston
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