Challenges and Recent Progress in Understanding High Latitude Climate Change

Some of the most rapid changes on the planet are taking place at high-latitudes. These changes appear in many Earth System components, including the ocean, atmosphere, cryosphere, and marine and terrestrial ecosystems, with regional and global implications. The changes are the result of a complex interplay between the components operating through a variety of processes and feedbacks. There is often a disagreement about the relative importance (and sometimes even the sign) of processes and feedbacks influencing high latitude changes, and the interactions can be difficult to tease out. I will describe strategies our team have been developing in Earth System Models to better understand the interactions, and processes that drive the planet's response to agents of change (including emissions of greenhouse gases, and aerosol and aerosol precursors, or land and water usage), and when those interactions are operating locally or acting through far field interactions. These strategies involve a combination of traditional and unusual techniques for decomposing and isolating Earth system processes, feedbacks and responses to better understand their role in our changing planet. I will touch on some of our (and other's) recent and current research using these strategies to better understand the planet, and some of our conclusions.