Uncertainty in climate change projections arises due to imperfections in climate models, the unpredictable nature of internal climate variability, and uncertainty surrounding the future pathway of greenhouse gas emissions. As a result, the climate community relies on ensembles of climate model simulations that attempt to explore and span uncertainty in these factors.
NE CASC Fellow Ambarish Karmalkar evaluates new methods including North American Regional Climate Change Assessment Program (NARCCAP) and the North America Coordinated Regional Climate Downscaling Experiment (NA-CORDEX) to address this uncertainty.
- In current climate models there are regions across the United States where the choices are inadequate to span known ranges of seasonal mean temperature and precipitation projections, including not capturing the high-end winter warming projections for the Northeast.
- Modeling methods show large variations in their ability to simulate the observed temperature trends.
- The simulated temperature trends are not systematically related to model performance over the historical period. In fact, models with the same skill in capturing seasonal mean climatology have been found to exhibit very different temperature trends over the historical period.
Karmalkar, A.V., 2018. Interpreting Results from the NARCCAP and NA-CORDEX Ensembles in the Context of Uncertainty in Regional Climate Change Projections. Bull. Amer. Meteor. Soc., 99, 2093–2106, https://doi.org/10.1175/BAMS-D-17-0127.1
This publication is part of NE CASC project Multi-model regional model simulations for future climate scenarios.
Written by Communications Intern Mike Crowley