Near-term climate change : Projections and predictability

Bindoff, Nathaniel L. and Durack, Paul J. and Slater, Andrew and Cameron-Smith, Philip and Chikamoto, Yoshimitsu and Clifton, Olivia and Ginoux, Paul and Holland, Marika and Holmes, Christopher and Infanti, Johnna and Jacob, Daniel and John, Jasmin and Knutson, Thomas and Lawrence, David and Lu, Jian and Murphy, Daniel and Naik, Vaishali and Robock, Alan and Vavrus, Steve and Ishii, Masayoshi and Corti, Susanna and Fichefet, Thierry and García-Serrano, Javier and Guemas, Virginie and Gray, Lesley and Hawkins, Ed and Smith, Doug and Stevenson, David S. and Voulgarakis, Apostolos and Weisheimer, Antje and Wild, Oliver and Woollings, Tim and Young, Paul and Krinner, Gerhard and Klimont, Zbigniew and Sedláček, Jan and van den Hurk, Bart and van Noije, Twan (2014) Near-term climate change : Projections and predictability. In: Climate Change 2013 - the Physical Science Basis : Working Group I Contribution to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, pp. 953-1028. ISBN 9781107057999

Abstract

This chapter assesses the scientific literature describing expectations for near-term climate (present through mid-century). Unless otherwise stated, ‘near-term’ change and the projected changes below are for the period 2016-2035 relative to the reference period 1986-2005. Atmospheric composition (apart from CO2; see Chapter 12) and air quality projections through to 2100 are also assessed. Decadal Prediction. The nonlinear and chaotic nature of the climate system imposes natual limits on the extent to which skilful predictions of climate statistics may be made. M.del-based ‘predictability’ studies, which probe these limits and investigate the physical mechanisms involved, support the potential for the skilful prediction of annual to decadal average temperature and, to a lesser extent precipitation. Predictions for averages of temperature, over large regions of the planet and for the global mean, exhibit positive skill when verified against observations for forecast periods up to ten years (high confidence). Predictions of precipitation over some land areas also exhibit positive skill. Decadal prediction is a new endeavour in climate science. The level of quality for climate predictions of annual to decadal average quantities is assessed from the past performance of initialized predictions and non-initialized simulations. {11.2.3, Figures 11.3 and 11.4}. In current results, observation-based initialization is the dominant contributor to the skill of predictions of annual mean temperature for the first few years and to the skill of predictions of the global mean surface temperature and the temperature over the North Atlantic, regions of the South Pacific and the tropical Indian Ocean for longer periods (high confidence).