Table of Contents
International Journal of Atmospheric Sciences
Volume 2016, Article ID 9657659, 7 pages
http://dx.doi.org/10.1155/2016/9657659
Research Article

Detecting Warming Hiatus Periods in CMIP5 Climate Model Projections

1Cornell University, Ithaca, NY 14850, USA
2NASA Langley Research Center, Hampton, VA 23681, USA

Received 12 February 2016; Revised 5 May 2016; Accepted 15 June 2016

Academic Editor: Prodromos Zanis

Copyright © 2016 Tony W. Li and Noel C. Baker. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The observed slow-down in the global-mean surface temperature (GST) warming from 1998 to 2012 has been called a “warming hiatus.” Certain climate models, operating under experiments which simulate warming by increasing radiative forcing, have been shown to reproduce periods which resemble the observed hiatus. The present study provides a comprehensive analysis of 38 CMIP5 climate models to provide further evidence that models produce warming hiatus periods during warming experiments. GST rates are simulated in each model for the 21st century using two experiments: a moderate warming scenario (RCP4.5) and high-end scenario (RCP8.5). Warming hiatus periods are identified in model simulations by detecting (1) ≥15-year periods lacking a statistically meaningful trend and (2) rapid changes in the GST rate which resemble the observed 1998–2012 hiatus. Under the RCP4.5 experiment, all tested models produce warming hiatus periods. However, once radiative forcing exceeds 5 W/m2—about 2°C GST increase—as simulated in the RCP8.5 experiment after 2050, nearly all models produce only positive warming trends. All models show evidence of rapid changes in the GST rate resembling the observed hiatus, showing that the climate variations associated with warming hiatus periods are still evident in the models, even under accelerated warming conditions.