title: Attributing physical and biological impacts to anthropogenic climate change.
abstract: Significant changes in physical and biological systems are occurring on all continents and in most oceans, with a concentration of available data in Europe and North America. Most of these changes are in the direction expected with warming temperature. Here we show that these changes in natural systems since at least 1970 are occurring in regions of observed temperature increases, and that these temperature increases at continental scales cannot be explained by natural climate variations alone. Given the conclusions from the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report that most of the observed increase in global average temperatures since the mid-twentieth century is very likely to be due to the observed increase in anthropogenic greenhouse gas concentrations, and furthermore that it is likely that there has been significant anthropogenic warming over the past 50 years averaged over each continent except Antarctica, we conclude that anthropogenic climate change is having a significant impact on physical and biological systems globally and in some continents.
authors.affiliation: NASA/Goddard Institute for Space Studies and Columbia Center for Climate Systems Research, 2800 Broadway, New York, New York 10025, USA. crosenzweig@giss.nasa.gov
authors.forename: Cynthia
authors.initials: C
authors.lastname: Rosenzweig
authors.forename: David
authors.initials: D
authors.lastname: Karoly
authors.forename: Marta
authors.initials: M
authors.lastname: Vicarelli
authors.forename: Peter
authors.initials: P
authors.lastname: Neofotis
authors.forename: Qigang
authors.initials: Q
authors.lastname: Wu
authors.forename: Gino
authors.initials: G
authors.lastname: Casassa
authors.forename: Annette
authors.initials: A
authors.lastname: Menzel
authors.forename: Terry L
authors.initials: TL
authors.lastname: Root
authors.forename: Nicole
authors.initials: N
authors.lastname: Estrella
authors.forename: Bernard
authors.initials: B
authors.lastname: Seguin
authors.forename: Piotr
authors.initials: P
authors.lastname: Tryjanowski
authors.forename: Chunzhen
authors.initials: C
authors.lastname: Liu
authors.forename: Samuel
authors.initials: S
authors.lastname: Rawlins
authors.forename: Anton
authors.initials: A
authors.lastname: Imeson
mesh_terms: D000383:Agriculture; D016208:Databases, Factual; D017753:Ecosystem; D016468:Forestry; D005843:Geography; D017752:Greenhouse Effect; D049673:History, 20th Century; D049674:History, 21st Century; D006802:Human Activities; D007053:Ice; D038622:Internationality; D008386:Marine Biology; D015233:Models, Statistical; D013696:Temperature
chemical_list: D007053:Ice