The University of Hawaii has announced that a university-led study has found that natural climate swings are the root cause of intensified monsoon rainfall in the Northern Hemisphere.
By examining the past 30 years of climate data, researchers found that summer monsoons have increased in intensity by a greater degree than can be attributed to greenhouse-gas warming alone. Intensity has increased by 9.5 percent per degree of global warming, compared to the predicted increase of 2.6 percent.
Researchers attribute much of the intensification to cooling of the eastern Pacific, which is the result of natural long-term fluctuations in ocean surface temperatures. Another natural climate swing, the Atlantic Multidecadal Oscillation, contributes to the monsoon escalation.
Image: Monsoon clouds in Arizona (Credit: Wikimedia Commons)