New Climate Change Findings and Future Plans

Ensemble historical simulations from 1870 to the present have been conducted with the NCAR Community Climate System Model (CCSM version 3-T85 atmospheric resolution) and the Parallel Climate Model (PCM–T42 atmosphere resolution) with five forcing agents that influence the time evolution of global and regional climate change during the 20th and 21st centuries. The forcings included are natural (volcanoes, solar, and dust aerosols) and anthropogenic (greenhouse gases, ozone (stratospheric and tropospheric) and sulfate aerosols. More recently, experiments have been performed with carbon aerosols and land cover changes. Simulations with various combinations of forcings have also been performed which allows for establishing which of the forcings contribute to the global and regional climate changes. The simulations show that the warming in the early part of the 20th century is mainly due to natural forcing (mostly a solar effect). An analysis of the interannual and decadal variability will be shown with special emphasis on the regional climate change. The talk will include a brief discussion of future plans and the computing resources devoted to climate change research by the U. S. Department of Energy and the National Science Foundation.