BOULDER, Colorado, June 12 (TNSrpt) -- The Cooperative Institute for Research in Environmental Sciences issued the following news: * * * Groundwater levels in the US Southwest more sensitive to climate shifts than in the Pacific Northwest Scientists use fossil groundwater, model simulations to identify regional differences in aquifer response during period of past warming * During the last ice age, when massive ice sheets blanketed large portions of North America, weather patterns pushed st  more