OREGON STATE UNIVERSITY

OSU professor computes ag cost of El Nino

05/04/1998

CORVALLIS, Ore. - If weather forecasters could predict El Nino events with perfect accuracy, farmers in the United States could save $323 million a year in crop losses associated with the unusual ocean warming El Nino brings.

But even if farmers used the current, less-than-perfect El Nino forecasting system when planting their crops, they could save $250 million annually.

Those are among the findings of a new research paper to appear in June in Climatic Change, an academic journal for those researching and monitoring shifts in the Earth's climate.

Richard Adams, a professor of agricultural and resource economics at Oregon State University, is a principal author of the research paper, titled "The Value of Improved ENSO Prediction to U.S. Agriculture." ENSO stands for El Nino Southern Oscillation.

Although the term El Nino has become synonymous with a series of strong Pacific storms of the type that swamped southern California this past winter, those storms are just one of El Nino's effects.

The name actually refers to ocean warming of designated areas off the Pacific coasts of Ecuador and Peru. If the five-month average surface temperature in these tropical Pacific regions is warmer by 0.5 degrees C between October to December, then that is classified as an El Nino event.

But ENSO also refers to the opposite event: If the average surface temperature in the same area and time period is 0.5 degrees C colder, then the year is classified an El Viejo, or below-normal ocean temperature year.

Being able to predict whether an upcoming winter would bring El Nino or El Viejo conditions would allow farmers to plan crops that would better withstand the unusual climatic year.

Scientists already have improved their forecasting of such ocean warming-or-cooling events up to 18 months in advance through a system of temperature monitoring equipment established in the southern Pacific ocean.

Farmers already are making use of this network. For example, strawberry farmers in California prepared for last winter's El Nino event by planting their crops on higher, well-drained fields in anticipation of lowland flooding.

Adams' study focuses on a 40-year period between 1947-1986. Nine of those were El Nino years, in which the water temperature was warmer than average.

The water temperature was colder than average for 12 of those years. By studying crop yields for the nine most valuable crops in the United States and putting them into a computer model, Adams and the other researchers who participated in the study were able to estimate both the crop yields and the economic effects of the changes in those yields.

The most recent research document is an expanded version of a study that Adams and the other authors conducted on the effects of El Nino on crops in the southeastern United States.

Adams also was involved with the first systematic study of the economic effects of climate change effects on agriculture, published in 1988. These and related research findings have been used by federal agencies such as the Environmental Protection Agency and the National Oceanic and Atmospheric Administration, and by similar international agencies.

Adams has worked at OSU since 1983, specializing in environmental and natural resource economics during a time when accelerated warming of the Earth has drawn considerable concern.

"The results of our recent study demonstrate that long-range forecasts of ENSO events, even if not perfect, have considerable economic value to the agricultural community," he said.