title: Detecting anthropogenic footprints in sea level rise.
abstract: While there is scientific consensus that global and local mean sea level (GMSL and LMSL) has risen since the late nineteenth century, the relative contribution of natural and anthropogenic forcing remains unclear. Here we provide a probabilistic upper range of long-term persistent natural GMSL/LMSL variability (P=0.99), which in turn, determines the minimum/maximum anthropogenic contribution since 1900. To account for different spectral characteristics of various contributing processes, we separate LMSL into two components: a slowly varying volumetric component and a more rapidly changing atmospheric component. We find that the persistence of slow natural volumetric changes is underestimated in records where transient atmospheric processes dominate the spectrum. This leads to a local underestimation of possible natural trends of up to ∼1 mm per year erroneously enhancing the significance of anthropogenic footprints. The GMSL, however, remains unaffected by such biases. On the basis of a model assessment of the separate components, we conclude that it is virtually certain (P=0.99) that at least 45% of the observed increase in GMSL is of anthropogenic origin.
authors.affiliation: Department of Civil Engineering, Research Institute for Water and Environment, University of Siegen, Paul-Bonatz-Strasse 9-11, 57076 Siegen, Germany.
authors.forename: Sönke
authors.initials: S
authors.lastname: Dangendorf
authors.affiliation: IMEDEA (UIB-CSIC), Miquel Marquès, 21, E-07190 Esporles, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Marcos
authors.affiliation: Department of Mathematics, University of Siegen, Walter-Flex-Strasse 3, 57072 Siegen, Germany.
authors.forename: Alfred
authors.initials: A
authors.lastname: Müller
authors.affiliation: Helmholtz-Centre Geesthacht, Max-Planck-Strasse 1, 21502 Geesthacht, Germany.
authors.forename: Eduardo
authors.identifier: http://orcid.org/0000-0002-7264-5743
authors.initials: E
authors.lastname: Zorita
authors.affiliation: Departement of Geoscience and Remote Sensing, Delft University of Technology, Stevinweg 1, 2628 Delft, Netherlands.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Riva
authors.affiliation: Department of Mathematics, University of Siegen, Walter-Flex-Strasse 3, 57072 Siegen, Germany.
authors.forename: Kevin
authors.initials: K
authors.lastname: Berk
authors.affiliation: Department of Civil Engineering, Research Institute for Water and Environment, University of Siegen, Paul-Bonatz-Strasse 9-11, 57076 Siegen, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Jensen