Explore high-dimensional hierarchical models for large-scale geophysical applications in this 24-minute conference talk by Lassi Roininem from LUT University. Delve into the world of uncertainty quantification (UQ) and its application in understanding complex physical systems and decision-making under uncertainty. Learn how Gaussian Process (GP) emulators can replace computationally expensive and complex codes, approximating functional relationships crucial for UQ purposes. Gain insights into the theoretical and numerical aspects of GP emulation, with a focus on real-world applications featuring 'large' characteristics, such as complex physical and numerical models or extensive datasets. Discover how these techniques are applied to global challenges like climate, tsunami, and earthquake problems, as part of a workshop bringing together early-career researchers and experts in the field.