title: Assessing "dangerous climate change": required reduction of carbon emissions to protect young people, future generations and nature.
abstract: We assess climate impacts of global warming using ongoing observations and paleoclimate data. We use Earth's measured energy imbalance, paleoclimate data, and simple representations of the global carbon cycle and temperature to define emission reductions needed to stabilize climate and avoid potentially disastrous impacts on today's young people, future generations, and nature. A cumulative industrial-era limit of ∼500 GtC fossil fuel emissions and 100 GtC storage in the biosphere and soil would keep climate close to the Holocene range to which humanity and other species are adapted. Cumulative emissions of ∼1000 GtC, sometimes associated with 2°C global warming, would spur "slow" feedbacks and eventual warming of 3-4°C with disastrous consequences. Rapid emissions reduction is required to restore Earth's energy balance and avoid ocean heat uptake that would practically guarantee irreversible effects. Continuation of high fossil fuel emissions, given current knowledge of the consequences, would be an act of extraordinary witting intergenerational injustice. Responsible policymaking requires a rising price on carbon emissions that would preclude emissions from most remaining coal and unconventional fossil fuels and phase down emissions from conventional fossil fuels.
authors: Earth Institute, Columbia University, New York, New York, United States of America.
authors: James
authors: J
authors: Hansen
authors: Pushker
authors: P
authors: Kharecha
authors: Makiko
authors: M
authors: Sato
authors: Valerie
authors: V
authors: Masson-Delmotte
authors: Frank
authors: F
authors: Ackerman
authors: David J
authors: DJ
authors: Beerling
authors: Paul J
authors: PJ
authors: Hearty
authors: Ove
authors: O
authors: Hoegh-Guldberg
authors: Shi-Ling
authors: SL
authors: Hsu
authors: Camille
authors: C
authors: Parmesan
authors: Johan
authors: J
authors: Rockstrom
authors: Eelco J
authors: EJ
authors: Rohling
authors: Jeffrey
authors: J
authors: Sachs
authors: Pete
authors: P
authors: Smith
authors: Konrad
authors: K
authors: Steffen
authors: Lise
authors: L
authors: Van Susteren
authors: Karina
authors: K
authors: von Schuckmann
authors: James C
authors: JC
authors: Zachos
mesh_terms: D000818:Animals; D002244:Carbon / Q000737:chemistry*; D057231:Climate Change; D018534:Earth, Planet; D017753:Ecosystem; D006801:Humans; D057766:Policy; D012941:Social Responsibility
chemical_list: D002244:Carbon