Researchers at Australia's Commonwealth Scientific and Industrial Research Organization said they used a climate model that included the effects of tiny particles called aerosols produced primarily in North America.
The study, led by Leon Rotstayn, principal scientist at the Center for Australian Weather and Climate Research, suggests aerosols can drive changes in atmospheric and oceanic circulation in the Southern Hemisphere.
The scientists said their model results suggest human-generated aerosols from the Northern Hemisphere may have contributed to increased rainfall in northwestern and central Australia, and decreased rainfall in parts of southern Australia.
The study was presented at Australia's Monash University last week during a joint conference of the Global Energy and Water Cycle Experiment and the Integrated Land Ecosystem-Atmosphere Processes Study.
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