title: Abrupt climate change.
abstract: Large, abrupt, and widespread climate changes with major impacts have occurred repeatedly in the past, when the Earth system was forced across thresholds. Although abrupt climate changes can occur for many reasons, it is conceivable that human forcing of climate change is increasing the probability of large, abrupt events. Were such an event to recur, the economic and ecological impacts could be large and potentially serious. Unpredictability exhibited near climate thresholds in simple models shows that some uncertainty will always be associated with projections. In light of these uncertainties, policy-makers should consider expanding research into abrupt climate change, improving monitoring systems, and taking actions designed to enhance the adaptability and resilience of ecosystems and economies.
authors.affiliation: Department of Geosciences and EMS Environment Institute, Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: R B
authors.initials: RB
authors.lastname: Alley
authors.forename: J
authors.initials: J
authors.lastname: Marotzke
authors.forename: W D
authors.initials: WD
authors.lastname: Nordhaus
authors.forename: J T
authors.initials: JT
authors.lastname: Overpeck
authors.forename: D M
authors.initials: DM
authors.lastname: Peteet
authors.forename: R A
authors.initials: RA
authors.lastname: Pielke
authors.forename: R T
authors.initials: RT
authors.lastname: Pierrehumbert
authors.forename: P B
authors.initials: PB
authors.lastname: Rhines
authors.forename: T F
authors.initials: TF
authors.lastname: Stocker
authors.forename: L D
authors.initials: LD
authors.lastname: Talley
authors.forename: J M
authors.initials: JM
authors.lastname: Wallace