Tara Banerjee will work with Kris Karnauskas to improve fundamental understanding of the drivers of global climate change and atmospheric dynamics by quantifying the 1) climate and 2) dynamical forcing efficacies of key forcing agents, and 3) the role of internal variability in each case. In today’s changing world, understanding our planet’s climate sensitivity to increasing atmospheric carbon dioxide is critical to future climate projections that inform policy makers. Climate sensitivity is quantified in terms of changes in global mean surface temperature in response to global mean radiative forcings. The project will use 35, 165-year transient experiment simulations spanning the historical period (1850-2015), using NCAR's fully coupled Earth System Model. It will provide valuable results that quantify the degree and impacts of climate change, reconcile model-observational discrepancies, and inform both long- and short-term climate policy.