What is the climate system able to do ‘on its own’?
- Publisher: Tellus B
(issn: 1600-0889, eissn: 0280-6509)
The climate of the Earth, like planetary climates in general, is broadly controlled by solar irradiation, planetary albedo and emissivity as well as its rotation rate and distribution of land (with its orography) and oceans. However, the majority of climate fluctuations that affect mankind are internal modes of the general circulation of the atmosphere and the oceans. Some of these modes, such as El Nino-Southern Oscillation (ENSO), are quasi-regular and have some longer-term predictive skill; others like the Arctic and Antarctic Oscillation are chaotic and generally unpredictable beyond a few weeks. Studies using general circulation models indicate that internal processes dominate the regional climate and that some like ENSO events have even distinct global signatures. This is one of the reasons why it is so difficult to separate internal climate processes from external ones caused, for example, by changes in greenhouse gases and solar irradiation. However, the accumulation of the warmest seasons during the latest two decades is lending strong support to the forcing of the greenhouse gases. As models are getting more comprehensive, they show a gradually broader range of internal processes including those on longer time scales, challenging the interpretation of the causes of past and present climate events further.Keywords: climate change, general circulation models, natural climate variability(Published: 12 March 2013)Citation: Tellus B 2013, 65, 20189, http://dx.doi.org/10.3402/tellusb.v65i0.20189This publication is part of a Thematic Cluster with papers presented at a conference held in Stockholm 21 - 23 May 2012, to honor the late Professor Bert Bolin for his outstanding contributions to climate science and his efforts to create a dialogue between policy makers and the scientific community. All papers within the cluster will be published online as soon as they have been accepted for publication. When all papers belonging to the cluster have been published, they will be summarized with a foreword describing the background and scope of the conference.Read the other papers from this thematic cluster here