A new study from the Lawrence Livermore National Laboratory reveals that observed changes in global precipitation are directly affected by human activities and cannot be explained by natural variability alone. The emissions of heat-trapping and ozone-depletinggases are affecting distribution of precipitation in two ways. Increasing temperatures are making wet regions wetter and dry regions drier. Secondly, atmospheric circulation patterns will push storm tracks and subtropical dry zones toward the poles. Researchers said their observations conclude that El Nino and La Nina are not to blame for the changes. They said that the increase in greenhouse gases is responsible for the changes and that these two effects are occurring simultaneously.