Paleocene–Eocene Thermal Maximum

Paleocene-Eocene Thermal MaximumPETMPaleocene-Eocene transitionPalaeocene-Eocene Thermal Maximuma very hot timeglobal thermal maximum at the Paleocene-Eocene boundarymost recentmuch warmerPalaeocene–Eocene Thermal MaximumPaleocene Eocene Thermal Maximum
The Paleocene–Eocene Thermal Maximum (PETM), alternatively "Eocene thermal maximum 1" (ETM1), and formerly known as the "Initial Eocene" or "Late Paleocene Thermal Maximum", was a time period with more than 5–8 °C global average temperature rise across the event.wikipedia
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Paleocene

PalaeoceneLate PaleocenePaleocene epoch
This climate event occurred at the time boundary of the Paleocene and Eocene geological epochs.
The end of the epoch was marked by the Paleocene–Eocene thermal maximum (PETM), which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification.

Eocene

Late EoceneMiddle EoceneEocene Epoch
This climate event occurred at the time boundary of the Paleocene and Eocene geological epochs.
The evolution of the Eocene climate began with warming after the end of the Palaeocene–Eocene Thermal Maximum (PETM) at 56 million years ago to a maximum during the Eocene Optimum at around 49 million years ago.

Ocean acidification

acidificationacidified the oceansacidification of the oceans
Since at least 1997, the Paleocene–Eocene Thermal Maximum has been investigated in geoscience as an analog to understand the effects of global warming and of massive carbon inputs to the ocean and atmosphere, including ocean acidification.
The most notable example is the Paleocene-Eocene Thermal Maximum (PETM), which occurred approximately 56 million years ago when massive amounts of carbon entered the ocean and atmosphere, and led to the dissolution of carbonate sediments in all ocean basins.

Cenozoic

Cenozoic EraCainozoicAge of Mammals
Of these, the PETM was the most extreme and perhaps the first (at least within the Cenozoic).
The Earth's climate had begun a drying and cooling trend, culminating in the glaciations of the Pleistocene Epoch, and partially offset by the Paleocene-Eocene Thermal Maximum.

North Atlantic Igneous Province

Thulean PlateauBritish Tertiary Volcanic ProvinceBrito-Arctic province
The onset of the Paleocene–Eocene Thermal Maximum has been linked to volcanism and uplift associated with the North Atlantic Igneous Province, causing extreme changes in Earth's carbon cycle and a 5 °C temperature rise.
Activity of the NAIP 55 million years ago may have caused the Paleocene–Eocene Thermal Maximum, where a large amount of carbon was released into the atmosphere and the Earth substantially warmed.

Δ13C

δ 13 Cδ'' 13 CPDB
The period is marked by a prominent negative excursion in carbon stable isotope ([[δ13C|]]) records from around the globe; more specifically, there was a large decrease in 13 C/ 12 C ratio of marine and terrestrial carbonates and organic carbon.
The release of large amounts of methane clathrate can impact on global δ 13 C values, as at the Paleocene–Eocene Thermal Maximum.

Paleogene

PalaeogenePaleogene PeriodLower Tertiary
The configuration of oceans and continents was somewhat different during the early Paleogene relative to the present day.
The end of the Paleocene (55.5/54.8 Mya) was marked by the Paleocene–Eocene Thermal Maximum, one of the most significant periods of global change during the Cenozoic, which upset oceanic and atmospheric circulation and led to the extinction of numerous deep-sea benthic foraminifera and on land, a major turnover in mammals.

Messel pit

MesselMessel Pit Fossil SiteMessel shales
The Messel pit biota, dated to the middle of the thermal maximum, indicate a tropical rainforest environment in South Germany.
The period was very close to the Paleocene–Eocene Thermal Maximum and the climate and ecology of the site were very different.

Climate across Cretaceous–Paleogene boundary

Climate across Cretaceous-Paleogene boundary66myaclimate of the early Palaeogene
This warming was superimposed on "long-term" early Paleogene warming, and is based on several lines of evidence.
This global cooling has been periodically disrupted by warm events such as the Paleocene–Eocene Thermal Maximum.

Anoxic event

anoxicanoxiaoceanic anoxic event
This may be due to bottom-water anoxia, or by changing ocean circulation patterns changing the temperatures of the bottom water.
The Paleocene–Eocene Thermal Maximum (PETM), which was characterized by a global rise in temperature and deposition of organic-rich shales in some shelf seas, shows many similarities to oceanic anoxic events.

Kaolinite

kaolinchina claykaolin clay
During the PETM, sediments are enriched with kaolinite from a detrital source due to denudation (initial processes such as volcanoes, earthquakes, and plate tectonics).
During the Paleocene–Eocene Thermal Maximum sediments were enriched with kaolinite from a detrital source due to denudation.

Extinction event

mass extinctionmass extinctionsextinction events
The PETM is accompanied by a mass extinction of 35-50% of benthic foraminifera (especially in deeper waters) over the course of ~1,000 years – the group suffering more than during the dinosaur-slaying K-T extinction (e.g., ).
The most dramatic example of sustained warming is the Paleocene–Eocene Thermal Maximum, which was associated with one of the smaller mass extinctions.

Toarcian turnover

Pliensbachian-Toarcian extinctionToarcian
Whether they only occurred during the long-term warming, and whether they are causally related to apparently similar events in older intervals of the geological record (e.g. the Toarcian turnover of the Jurassic) are open issues.

Eocene Thermal Maximum 2

ETM-2Elmo horizonEocene Layer of Mysterious Origin
Another hyperthermal clearly occurred at approximately 53.7 Ma, and is now called ETM-2 (also referred to as H-1, or the Elmo event).
The most extreme and best-studied event, the Paleocene-Eocene Thermal Maximum (PETM or ETM-1), occurred about 1.8 million years before ETM-2, at approximately 55.5 Ma. Other hyperthermals likely followed ETM-2 at nominally 53.6 Ma (H-2), 53.3 (I-1), 53.2 (I-2) and 52.8 Ma (informally called K, X or ETM-3).

Abrupt climate change

Climate surpriseabruptabrupt changes
Past events include the end of the Carboniferous Rainforest Collapse, Younger Dryas, Dansgaard-Oeschger events, Heinrich events and possibly also the Paleocene–Eocene Thermal Maximum.

Clathrate gun hypothesis

destabilise the environmentdissociationlarge releases of underwater methane
At one point there seemed to be stronger evidence that runaway methane clathrate breakdown may have caused drastic alteration of the ocean environment (such as ocean acidification and ocean stratification) and of the atmosphere over timescales of tens of thousands of years during the Paleocene–Eocene Thermal Maximum 56 million years ago, and most notably the Permian–Triassic extinction event, when up to 96% of all marine species became extinct, 252 million years ago.

Coccolithophore

coccolithophoridcoccolithophorescoccolithophorids
However, the strong acids used to simulate the natural increase in acidity which would result from elevated concentrations may have given misleading results, and the most recent evidence is that coccolithophores (E. huxleyi at least) become more, not less, calcified and abundant in acidic waters.
Of particular interest are fossils dating back to the Palaeocene-Eocene Thermal Maximum 55 million years ago.

Methane clathrate

methane hydratemethane hydratesmethane ice
The most obvious feedback mechanism that could amplify the initial perturbation is that of methane clathrates.
Events possibly linked in this way are the Permian-Triassic extinction event and the Paleocene-Eocene Thermal Maximum.

Climate sensitivity

Equilibrium climate sensitivity50% increase in atmospheric CO2are net positive
The Paleocene–Eocene Thermal Maximum provides a good opportunity to study the climate system when it is in a warm state.

Azolla event

800,000 years of arctic azolla bloomsa particularly swift reduction
* Paleocene-Eocene Thermal Maximum

Epoch (geology)

epochepochsgeological epoch
This climate event occurred at the time boundary of the Paleocene and Eocene geological epochs.

Carbon cycle

carboncarbon cyclingglobal carbon cycle
The onset of the Paleocene–Eocene Thermal Maximum has been linked to volcanism and uplift associated with the North Atlantic Igneous Province, causing extreme changes in Earth's carbon cycle and a 5 °C temperature rise.

Stable isotope ratio

stable isotopestableisotope ratio
The period is marked by a prominent negative excursion in carbon stable isotope ([[δ13C|]]) records from around the globe; more specifically, there was a large decrease in 13 C/ 12 C ratio of marine and terrestrial carbonates and organic carbon.

Carbon-12

12 CCarbon 12Hoyle state
The period is marked by a prominent negative excursion in carbon stable isotope ([[δ13C|]]) records from around the globe; more specifically, there was a large decrease in 13 C/ 12 C ratio of marine and terrestrial carbonates and organic carbon.

Carbonate

carbonatescarbonaceousCO 3
The period is marked by a prominent negative excursion in carbon stable isotope ([[δ13C|]]) records from around the globe; more specifically, there was a large decrease in 13 C/ 12 C ratio of marine and terrestrial carbonates and organic carbon.