Past extreme warming events linked to massive carbon release from thawing permafrost

  title={Past extreme warming events linked to massive carbon release from thawing permafrost},
  author={Robert M. DeConto and Simone Galeotti and Mark Pagani and David Tracy and Kevin M. Schaefer and Tingjun Zhang and David D. Pollard and David J. Beerling},
Between about 55.5 and 52 million years ago, Earth experienced a series of sudden and extreme global warming events (hyperthermals) superimposed on a long-term warming trend. The first and largest of these events, the Palaeocene–Eocene Thermal Maximum (PETM), is characterized by a massive input of carbon, ocean acidification and an increase in global temperature of about 5 °C within a few thousand years. Although various explanations for the PETM have been proposed, a satisfactory model that… 

A seasonality trigger for carbon injection at the Paleocene–Eocene Thermal Maximum

Abstract. The Paleocene–Eocene Thermal Maximum (PETM) represents a ~170 kyr episode of anomalous global warmth ~56 Ma ago. The PETM is associated with rapid and massive injections of 13C-depleted

Very large release of mostly volcanic carbon during the Paleocene-Eocene Thermal Maximum

Boron isotope data are presented that show that the ocean surface pH was persistently low during the PETM, and enhanced burial of organic matter seems to have been important in eventually sequestering the released carbon and accelerating the recovery of the Earth system.

Widespread Warming Before and Elevated Barium Burial During the Paleocene‐Eocene Thermal Maximum: Evidence for Methane Hydrate Release?

It is speculated the most complete explanation for early warming and rise in Ba supply is that hydrate dissociation acted as a positive feedback and caused the CIE, which implies hydrates are more temperature sensitive than previously considered, and may warrant reconsideration of the political assignment of 2 °C warming as a safe future scenario.

Maximum Eocene Thermal − Extreme warming of tropical waters during the Paleocene

The Paleocene–Eocene Thermal Maximum (PETM), ca. 56 Ma, was a major global environmental perturbation attributed to a rapid rise in the concentration of greenhouse gases in the atmosphere.

High latitude hydrological changes during the Eocene Thermal Maximum 2

Reduced carbon cycle resilience across the Palaeocene–Eocene Thermal Maximum

Abstract. Several past episodes of rapid carbon cycle and climate change are hypothesised to be the result of the Earth system reaching a tipping point beyond which an abrupt transition to a new

Open Research Online Extreme warming of tropical waters during the Paleocene-Eocene Thermal Maximum

The Paleocene–Eocene Thermal Maximum (PETM), ca. 56 Ma, was a major global environmental perturbation attributed to a rapid rise in the concentration of greenhouse gases in the atmosphere.



Astronomical pacing of late Palaeocene to early Eocene global warming events

A distinct carbonate-poor red clay layer in deep-sea cores from Walvis ridge is reported, which is term the Elmo horizon, which has similar geochemical and biotic characteristics as the Palaeocene–Eocene thermal maximum, but of smaller magnitude, suggesting that it represents a second global thermal maximum.

Subtropical Arctic Ocean temperatures during the Palaeocene/Eocene thermal maximum

It is shown that sea surface temperatures near the North Pole increased from ∼18 °C to over 23‬°C during this event, which suggests that higher-than-modern greenhouse gas concentrations must have operated in conjunction with other feedback mechanisms—perhaps polar stratospheric clouds or hurricane-induced ocean mixing—to amplify early Palaeogene polar temperatures.

Paleocene-Eocene Thermal Maximum and the Opening of the Northeast Atlantic

The Paleocene-Eocene thermal maximum (PETM) has been attributed to a sudden release of carbon dioxide and/or methane. 40Ar/39Ar age determinations show that the Danish Ash-17 deposit, which overlies

Possible methane-induced polar warming in the early Eocene

Estimates of Eocene wetland areas are considered and it is suggested that the flux of methane, an important greenhouse gas, may have been substantially greater during the Eocene than at present.

Rapid Acidification of the Ocean During the Paleocene-Eocene Thermal Maximum

Geochemical data from five new South Atlantic deep-sea sections indicate that a large mass of carbon dissolved in the ocean at the Paleocene-Eocene boundary and that permanent sequestration of this carbon occurred through silicate weathering feedback.

Dissociation of oceanic methane hydrate as a cause of the carbon isotope excursion at the end of the Paleocene

Isotopic records across the “Latest Paleocene Thermal Maximum“ (LPTM) indicate that bottom water temperature increased by more than 4°C during a brief time interval (<104 years) of the latest

Enhanced chemistry-climate feedbacks in past greenhouse worlds

Results from a series of three-dimensional Earth system modeling simulations indicate that the greenhouse worlds of the early Eocene and late Cretaceous maintained high concentrations of methane, tropospheric ozone, and nitrous oxide, and point to chemistry-climate feedbacks as possible amplifiers of climate sensitivity in the Anthropocene.

Multiple early Eocene hyperthermals: Their sedimentary expression on the New Zealand continental margin and in the deep sea

The Paleocene–Eocene thermal maximum (PETM) ca. 55.5 Ma was a geologically brief interval characterized by massive influx of isotopically light carbon, extreme changes in global climate, and profound

Early Cenozoic decoupling of the global carbon and sulfur cycles

[1] Changes in carbon and sulfur cycling over geologic time may have caused considerable modification of atmospheric and oceanic composition and climate. Here we calculate pyrite sulfur (Spy) and