London (July 26, 2007)- An international team of scientists has established a link between changing rainfall patterns and global warming. The scientists showed that human influence has caused an increase annual average rainfall in the mid-latitudes of the Northern Hemisphere and a decrease in India and parts of Africa. “We show that anthropogenic forcing has had a detectable influence on observed changes in average precipitation within latitudinal bands,” the researchers wrote in their paper, which was published in the journal Nature.
“These changes cannot be explained by internal climate variability or natural forcing,” the scientists said. The team cited an increase in greenhouse gases and sulphate aerosols in the atmosphere as major drivers of the change. Natural factors such as volcanic eruptions contributed to a lesser extent.
“This study shows that there has been a significant human effect on global rainfall patterns, with human influence causing a decrease in rainfall in some regions, and an increase in rainfall in others,” said co-author Nathan Gillett of the Climatic Research Unit at the University of East Anglia.