title: Climatic irregular staircases: generalized acceleration of global warming.
abstract: Global warming rates mentioned in the literature are often restricted to a couple of arbitrary periods of time, or of isolated values of the starting year, lacking a global view. In this study, we perform on the contrary an exhaustive parametric analysis of the NASA GISS LOTI data, and also of the HadCRUT4 data. The starting year systematically varies between 1880 and 2002, and the averaging period from 5 to 30 yr - not only decades; the ending year also varies . In this way, we uncover a whole unexplored space of values for the global warming rate, and access the full picture. Additionally, stairstep averaging and linear least squares fitting to determine climatic trends have been sofar exclusive. We propose here an original hybrid method which combines both approaches in order to derive a new type of climatic trend. We find that there is an overall acceleration of the global warming whatever the value of the averaging period, and that 99.9% of the 3029 Earth's climatic irregular staircases are rising. Graphical evidence is also given that choosing an El Niño year as starting year gives lower global warming rates - except if there is a volcanic cooling in parallel. Our rates agree and generalize several results mentioned in the literature.
authors.affiliation: Belgian National Fund of Scientific Research (F.R.S.-FNRS), Belgium.|Earth and Life Institute, Georges Lemaître Centre for Earth and Climate Research, Université catholique de Louvain, Louvain-la-Neuve, Belgium.
authors.forename: Bernard
authors.initials: B
authors.lastname: De Saedeleer
references.citation: Nature. 2014 Jan 16;505(7483):276-8
references.pmid: 24429612
references.citation: Science. 2014 Aug 22;345(6199):860-1
references.pmid: 25146261
references.citation: Proc Natl Acad Sci U S A. 2009 Feb 10;106(6):1704-9
references.pmid: 19179281
references.citation: Proc Natl Acad Sci U S A. 2006 Sep 26;103(39):14288-93
references.pmid: 17001018
references.citation: Science. 2014 Aug 22;345(6199):897-903
references.pmid: 25146282