title: Role of land-surface changes in arctic summer warming.
abstract: A major challenge in predicting Earth's future climate state is to understand feedbacks that alter greenhouse-gas forcing. Here we synthesize field data from arctic Alaska, showing that terrestrial changes in summer albedo contribute substantially to recent high-latitude warming trends. Pronounced terrestrial summer warming in arctic Alaska correlates with a lengthening of the snow-free season that has increased atmospheric heating locally by about 3 watts per square meter per decade (similar in magnitude to the regional heating expected over multiple decades from a doubling of atmospheric CO2). The continuation of current trends in shrub and tree expansion could further amplify this atmospheric heating by two to seven times.
authors.affiliation: Institute of Arctic Biology; University of Alaska Fairbanks, Fairbanks, AK 99775, USA. terry.chapin@uaf.edu
authors.forename: F S
authors.initials: FS
authors.lastname: Chapin
authors.forename: M
authors.initials: M
authors.lastname: Sturm
authors.forename: M C
authors.initials: MC
authors.lastname: Serreze
authors.forename: J P
authors.initials: JP
authors.lastname: McFadden
authors.forename: J R
authors.initials: JR
authors.lastname: Key
authors.forename: A H
authors.initials: AH
authors.lastname: Lloyd
authors.forename: A D
authors.initials: AD
authors.lastname: McGuire
authors.forename: T S
authors.initials: TS
authors.lastname: Rupp
authors.forename: A H
authors.initials: AH
authors.lastname: Lynch
authors.forename: J P
authors.initials: JP
authors.lastname: Schimel
authors.forename: J
authors.initials: J
authors.lastname: Beringer
authors.forename: W L
authors.initials: WL
authors.lastname: Chapman
authors.forename: H E
authors.initials: HE
authors.lastname: Epstein
authors.forename: E S
authors.initials: ES
authors.lastname: Euskirchen
authors.forename: L D
authors.initials: LD
authors.lastname: Hinzman
authors.forename: G
authors.initials: G
authors.lastname: Jia
authors.forename: C-L
authors.initials: CL
authors.lastname: Ping
authors.forename: K D
authors.initials: KD
authors.lastname: Tape
authors.forename: C D C
authors.initials: CD
authors.lastname: Thompson
authors.forename: D A
authors.initials: DA
authors.lastname: Walker
authors.forename: J M
authors.initials: JM
authors.lastname: Welker
mesh_terms: D000413:Alaska; D001110:Arctic Regions; D017752:Greenhouse Effect; D028222:Picea; D012621:Seasons; D014197:Trees