Paleo Slide Set: Coral Paleoclimatology
Reef flat, Palau Archipelago (Micronesia).

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 
is climate. 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 Nino/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.

Photo Credits:
Jerry Wellington
Department of Biology, University of Houston