If humans cause global warming, then humans also cause the drying climate and lack of precipitation caused by global warming, at least according to new research.

Laurence Livermore National Laboratory (LLNL) scientists found in a new study that a lack of ocean and land precipitation cannot be of natural cause and must be attributed to human activity, according to a press release.

The researchers work was published Monday in the journal Proceedings of the National Academy of Sciences.

"Both these changes are occurring simultaneously in global precipitation and this behavior cannot be explained by natural variability alone," said LLNL lead author Kate Marvel. "External influences such as the increase in greenhouse gases are responsible for the changes."

The warming climate has already shown some of its adverse affects on the weather and such trends are expected continue. For example, wet regions will become wetter and dry regions will become drier. Hurricanes, thunderstorms and rainfall can be more severe and dry climates make natural disasters like forest fires and droughts much worse.

"In combination, manmade increases in greenhouse gases and stratospheric ozone depletion are expected to lead to both an intensification and redistribution of global precipitation," said Céline Bonfils, another LLNL study author. "The fact that we see both of these effects simultaneously in the observations is strong evidence that humans are affecting global precipitation."

The researchers compared climate model affirmations with previous global observations. The Global Precipitation Climatology Project developed a model spanning from 1972 to 2012 finding that natural occurrences do not change precipitation patterns. In some instances, natural changes in the climate can intensify precipitation, but it is rare for these to happen together naturally.

"Most previous work has focused on either thermodynamic or dynamic changes in isolation," Marvel said. "By looking at both, we were able to identify a pattern of precipitation change that fits with what is expected from human-caused climate change."