The University of Arizona

Climate Modeling

photo of the super computer Blue Sky

Blue Sky is a computer at the the National Center for Atmospheric Research in Boulder, Colorado devoted to running climate models in support of the Intergovernmental Panel on Climate Change.
Credit: The University Corporation for Atmospheric Research

How Climate Models Work
News headlines about climate change research are often based on climate models. But to most people, how models function is mysterious. This section describes various aspects of state-of-the-art climate models, including model representation of time and space, the role greenhouse gas emissions play, and how models are evaluated.

Global Scale Modeling
Models have improved over the years, making their projections more reliable. This section describes some of the improvements and why they have made model projections more trustworthy.

Uncertainty in Global Models
Despite the many advances in recent years, uncertainties remain in Global Climate Model projections. This section considers some uncertainties that relate to physical factors. These include the difficulty in modeling clouds and the challenges of assessing the counteractive cooling effect of airborne pollution particles.

Regional Modeling
As Global Climate Models (GCMs) have improved, so have the prospects for regional models. This section describes how some of the GCM improvements influence regional models’ ability to accurately predict climate features with effects at smaller spatial scales, such as the jet stream, tropical storms, and elevation effects.

Downscaling Techniques
Modelers typically use either statistical downscaling or dynamical downscaling to convert input from Global Climate Models into information that can be refined at the regional scale. These techniques are described here, as is sensitivity analysis, a method for considering the vulnerability of a sector or organization to climate change.