Paula Leighton, SciDev.Net

Central America and the Caribbean will see a major decrease in summer rainfall by the end of the century because of climate change, say researchers.

They made their prediction, published in the Proceedings of the National Academy of Sciences today, by comparing ten computer simulations of climate change in the region.

All the models calculated that, by the end of the 21st century, the area would receive less rainfall between June and August, although they did not agree on which year this trend would become detectable.

The predicted drop in rainfall varied between models. On average, they suggested that by the last 30 years of the century, there would be 25 per cent less rain than during 1901–1960.

Although this equates to a reduction of just 0.5–1 millimetre of rain a day over most of the region, the researchers say this figure is substantial as the region currently receives just two millimetres of rain a day in the summer.

The researchers, led by David Neelin of the University of California at Los Angeles, United States, say this drop in rainfall "stands out as demanding attention".

But Hugo Beltrami, a professor of environmental sciences at Canada's St. Francis Xavier University, says the results are interesting but should be treated with caution.

"Comparing models is tricky, due to their variation in resolution and coverage," he told SciDev.Net. "Reaching accurate conclusions is particularly difficult, especially when studying areas as extensive as the Caribbean and Central America."

Link to paper in Proceedings of the National Academy of Sciences

Reference: Proceedings of the National Academy of Sciences 103, 6110 (2006)