Yannick Donnadieu

French National Centre for Scientific Research | CNRS · Institut national des sciences de l'univers (INSU)

Paleoclimate model simulations provide reference data to help interpret the geological record and offer a unique opportunity to evaluate the performance of current models under diverse boundary conditions. Here, we present a dataset of 35 climate model simulations of the warm early Eocene Climatic Optimum (EECO; ~ 50 million years ago) and correspo...

Databases of 3D paleoclimate model simulations are increasingly used within global biogeochemical models for the Phanerozoic Eon. This improves the accuracy of the surface processes within the biogeochemical models, but the approach is limited by the availability of large numbers of paleoclimate simulations at different pCO2 levels and for differen...

Diapycnal mixing in the ocean interior is largely fueled by internal tides. Mixing schemes that represent the breaking of internal tides are now routinely included in ocean and earth system models applied to the modern and future. However, this is more rarely the case in climate simulations of deep‐time intervals of the Earth, for which estimates o...

Databases of 3D paleoclimate model simulations are increasingly used within global biogeochemical models for the Phanerozoic Eon. This improves the accuracy of the surface processes within the biogeochemical models, but the approach is limited by the availability of large numbers of paleoclimate simulations at different pCO2 levels and for differen...

Most of the primary productivity in the ocean comes from phytoplankton, and is impacted, among other things, by the amount of nutrients available, as well as by temperature. The Late Miocene and Pliocene were marked by global aridification, linked to the emergence of the large deserts, likely increasing the input of dust and thus nutrients into the...

The Miocene (23.03–5.33 Ma) is recognized as a period with close to modern‐day paleogeography, yet a much warmer climate. With large uncertainties in future hydroclimate projections, Miocene conditions illustrate a potential future analog for the Earth system. A recent opportunistic Miocene Model Intercomparison Project 1 (MioMIP1) focused on synth...

Diapycnal mixing in the ocean interior is largely fueled by internal tides. Mixing schemes that represent the breaking of internal tides are now routinely included in ocean and earth system models applied to the modern and future. However, this is more rarely the case in climate simulations of deep-time intervals of the Earth, for which estimates o...

Earth's hydrological cycle is expected to intensify in response to global warming, with a “wet‐gets‐wetter, dry‐gets‐drier” response anticipated over the ocean. Subtropical regions (∼15°–30°N/S) are predicted to become drier, yet proxy evidence from past warm climates suggests these regions may be characterized by wetter conditions. Here we use an...

The Asian monsoons are triggered by complex interactions between the atmosphere, Asian and African orography, and the surrounding oceans, resulting in highly seasonal climate and specific regional features. It was thought that the Asian monsoon was established during the Neogene, but recent evidence for monsoon-like precipitation seasonality occurr...

The Late Miocene Biogenic Bloom (LMBB) is a late Miocene to early Pliocene oceanographic event characterized by high accumulation rates of opal from diatoms and calcite from calcareous nannofossils and planktic foraminifera. This multi‐million year event has been recognized in sediment cores from the Pacific, Atlantic, and Indian Oceans. Based on e...

Estimates of global mean near‐surface air temperature (global SAT) for the Cenozoic era rely largely on paleo‐proxy data of deep‐sea temperature (DST), with the assumption that changes in global SAT covary with changes in the global mean deep‐sea temperature (global DST) and global mean sea‐surface temperature (global SST). We tested the validity o...

During the late Miocene, global cooling occurred alongside the establishment of near‐modern terrestrial and marine ecosystems. Significant (3°C–5°C) sea surface cooling from 7.5 to 5.5 Ma is recorded by proxies at midlatitudes to high latitudes, yet the magnitude of tropical cooling and the role of atmospheric carbon dioxide (pCO2) in driving this...

Surface currents constitute an efficient transport agent for (larvae of) marine faunas, while the circulation of water masses in the ocean interior drives nutrient redistribution, ventilates the ocean and contributes to shaping surface biological productivity and the benthic redox landscape. Therefore, a robust understanding of ocean circulation, b...

Mechanisms that drive cyclicity in marine sediment deposits during hothouse climate periods in response to Earth's orbit variations remain debated. Orbital cycles fingerprint in the oceanographic records results from the combined effect of terrestrial (e.g., Weathering derived nutrient supply, freshwater discharge) and oceanic (e.g., productivity,...

The Permian–Triassic Mass Extinction (PTME), life’s most severe crisis1, has been attributed to intense global warming triggered by CO2 emissions from Large Igneous Province volcanism2–8. It remains unclear, however, why super-greenhouse conditions persisted for around five million years after the volcanic episode, when Earth system feedbacks shoul...

Inconsistencies in the Eocene climates of East Asia have been revealed in both geological studies and simulations. Several earlier reconstructions showed an arid zonal band in mid‐latitude China, but others showed a humid climate in the same region. Moreover, previous Eocene modeling studies have demonstrated that climate models can simulate both s...

Earth's hydrological cycle is expected to intensify in response to global warming , with a 'wet-gets-wetter, dry-gets-drier' response anticipated. The subtrop-ics (~15-30°N/S) are predicted to become drier, yet proxy evidence from past warm climates suggests these regions may be characterised by wetter conditions. Here we use an integrated data-mod...

The Ordovician global cooling trend observed by several temperature proxies, which coincides with one of the most significant evolutionary diversifications on Earth, is yet to be fully understood. This study presents new simulations of pCO2 and surface temperatures using a spatially resolved climate-carbon cycle Earth system model fed with refined...

The Modern Ocean is characterized by the formation of deep‐water in the North Atlantic Ocean (i.e., NADW). This feature has been attributed to the modern geography, in which the Atlantic Ocean is a large basin extending from northern polar latitudes to the Southern Ocean, the latter enabling the connection of the otherwise isolated Atlantic with th...

Earth’s long-term climate may have profoundly influenced plant evolution. Local climatic factors, including water availability, light, and temperature, play a key role in plant physiology and growth, and have fluctuated substantially over geological time. However, the impact of these key climate variables on global plant biomass across the Phaneroz...

The early Eocene (∼56–48 Myr ago) is characterized by high CO2 estimates (1,200–2,500 ppmv) and elevated global temperatures (∼10°C–16°C higher than modern). However, the response of the hydrological cycle during the early Eocene is poorly constrained, especially in regions with sparse data coverage (e.g., Africa). Here, we present a study of Afric...

The early Eocene greenhouse climate maintained by high atmospheric CO2 concentrations serves as a testbed for future climate changes dominated by increasing CO2 forcing. In particular, the early Eocene Arctic region is important in the context of future CO2 driven climate warming in the northern polar region and associated shrinking Arctic sea ice....

The drivers of the evolution of the South Asian Monsoon remain widely debated. An intensification of monsoonal rainfall recorded in terrestrial and marine sediment archives from the earliest Miocene (23–20 million years ago (Ma)) is generally attributed to Himalayan uplift. However, Indian Ocean palaeorecords place the onset of a strong monsoon aro...

Here, we compare the ocean overturning circulation of the early Eocene (47–56 Ma) in eight coupled climate model simulations from the Deep‐Time Model Intercomparison Project (DeepMIP) and investigate the causes of the observed inter‐model spread. The most common global meridional overturning circulation (MOC) feature of these simulations is the ant...

The first forests appeared on the continents during the Givetian stage of the Devonian. The fossil record shows that, by the end of the Devonian, vascular plants and forests were common and widespread in the wet lowlands. Although the impact of this major event on chemical weathering of the continents is reasonably known, the coeval change in physi...

At the junction of greenhouse and icehouse climate states, the Eocene–Oligocene Transition (EOT) is a key moment in Cenozoic climate history. While it is associated with severe extinctions and biodiversity turnovers on land, the role of terrestrial climate evolution remains poorly resolved, especially the associated changes in seasonality. Some pal...

The early Eocene (~56-48 million years ago) is characterised by high CO2 estimates (1200-2500 44 ppmv) and elevated global temperatures (~10 to 16°C higher than modern). However, the response 45 of the hydrological cycle during the early Eocene is poorly constrained, especially in regions with 46 sparse data coverage (e.g. Africa). Here we present...

The Miocene period saw substantially warmer Earth surface temperatures than today, particularly during a period of global warming called the Mid Miocene Climatic Optimum (MMCO; ∼17–15 Ma). However, the long‐term drivers of Miocene climate remain poorly understood. By using a new continuous climate‐biogeochemical model (SCION), we can investigate th...

Although the role of Earth’s orbital variations in driving global climate cycles has long been recognized, their effect on evolution is hitherto unknown. The fossil remains of coccolithophores, a key calcifying phytoplankton group, enable a detailed assessment of the effect of cyclic orbital-scale climate changes on evolution because of their abund...

Supplementary Information and Figures

Supplementary Information and Figures File

During the late Miocene, global cooling occurred alongside the establishment of near-modern terrestrial and marine ecosystems. Significant (3 to 5 °C) sea surface cooling from 7.5 to 5.5 Ma is recorded by proxies at mid to high latitudes, yet the magnitude of tropical cooling and the role of atmospheric carbon dioxide (pCO2) in driving this trend a...

During the late Miocene, global cooling occurred alongside the establishment of near-modern terrestrial and marine ecosystems. Significant (3 to 5 °C) sea surface cooling from 7.5 to 5.5 Ma is recorded by proxies at mid to high latitudes, yet the magnitude of tropical cooling and the role of atmospheric carbon dioxide (pCO2) in driving this trend a...

Plants are likely to have had a profound influence on Earth’s long-term climate through their role in drawing down CO2 and emitting O2 into the atmosphere and their interactions with soils and minerals. Local climatic factors, including water availability, light, and temperature, play a key role in plant physiology and growth and have fluctuated su...

Recent studies suggest increasing sensitivity to orbital variations across the Eocene-Oligocene greenhouse to icehouse climate transition. However, climate simulations and paleoenvironmental studies mostly provide snapshots of the past climate, therefore overlooking the role of this short-term variability in driving major environmental changes and...

The Cenomanian‐Turonian period recorded one of the largest disruptions to the oxygen and carbon cycles, the Oceanic Anoxic Event 2 (OAE2, 94 Ma). This event is global, yet paleo‐reconstructions document heterogeneous ocean oxygenation states and sedimentary carbon contents, temporally and spatially, suggesting that several mechanisms are at play. T...

Marine ecosystems with a diverse range of animal groups became established during the early Cambrian (~541 to ~509 Ma). However, Earth’s environmental parameters and palaeogeography in this interval of major macro-evolutionary change remain poorly constrained. Here, we test contrasting hypotheses of continental configuration and climate that have p...

The Miocene epoch, spanning 23.03–5.33 Ma, was a dynamic climate of sustained, polar amplified warmth. Miocene atmospheric CO2 concentrations are typically reconstructed between 300 and 600 ppm and were potentially higher during the Miocene Climatic Optimum (16.75–14.5 Ma). With surface temperature reconstructions pointing to substantial midlatitud...

At the junction of greenhouse and icehouse climate phases, the Eocene-Oligocene Transition (EOT) is a key moment in the history of the Cenozoic climate. Yet, while it is associated with severe extinctions and biodiversity turnovers, terrestrial climate evolution remains poorly resolved. Paleobotanical and geochemical continental records suggest a m...

It is important to understand how Earth's surface conditions have changed over geological timescales and what has driven these changes. Much of this understanding comes from combining geological and geochemical data with global biogeochemical models, but designing and running computer models over these vast timeframes poses a serious challenge. Tra...

We present results from an ensemble of eight climate models, each of which has carried out simulations of the early Eocene climate optimum (EECO, ∼ 50 million years ago). These simulations have been carried out in the framework of the Deep-Time Model Intercomparison Project (DeepMIP; http://www.deepmip.org, last access: 10 January 2021); thus, all...

The Phanerozoic period covers the last 542 million years of Earth’s history, about 12% of the history of our planet. With regard to the evolution of life, the Phanerozoic experienced major events such as the rapid diversification of multicellular organisms which first appeared in the Cambrian (541–485 Ma), the colonization of continental surfaces b...

A new and innovative workflow predicts presence, type and thickness of marine carbonates through geological Time and Space. It couples exhaustive data mining, accurate paleogeography and deep time paleoclimate modeling to reveal the waning and waxing of carbonate deposition throughout geological history with many, yet unmapped, implications for geo...

The origins and development of the arid and highly seasonal steppe-desert biome in Central Asia, the largest of its kind in the world, remain largely unconstrained by existing records. It is unclear how Cenozoic climatic, geological, and biological forces, acting at diverse spatial and temporal scales, shaped Central Asian ecosystems through time....

The early Eocene (∼55 Ma) was the warmest period of the Cenozoic and was most likely characterized by extremely high atmospheric CO2 concentrations. Here, we analyze simulations of the early Eocene performed with the IPSL-CM5A2 Earth system model, set up with paleogeographic reconstructions of this period from the DeepMIP project and with different...

The ongoing surge of international research on Asian Climate and Tectonics enables to better assess interactions between forcing mechanisms (global climate, India-Asia collision, Tibetan Plateau growth) and paleoenvironmental changes (monsoons, aridification), land-sea distribution, surface processes, paleobiogeographic evolution and the global car...

These files contain the output of Cretaceous global climate simulations conducted using the coupled ocean-atmosphere FOAM general circulation model. They are available every 10 Myrs between 150 Ma and 60 Ma, both included. For each time slice, numerous CO2 levels were used. Files are provided in netcdf format, fully compatible with GIS softwares,...

A century ago, the pioneering book published in 1924 Die Klimate der geologischen Vorzeit explained by plate motion the evolution of vegetation revealed in sedimentary records. Nevertheless, they did not invoke climate changes. In the second part of the 20th century, the intricate relationship between tectonics, long‐term carbon cycle, and climate...

The Cenozoic onset and development of the Asian monsoons remain unclear and have generated much debate, as several hypotheses regarding circulation patterns at work in Asia during the Eocene have been proposed in the last decades. These include a) the existence of modern-like monsoons since the early Eocene; b) that of a weak South Asian Monsoon (S...

The effects of orography on climate are investigated with a coupled ocean–atmosphere general circulation model (IPSL-CM5). Results are compared with previous investigations in order to dig out robust consequences of the lack of orography on the global scale. Emphasis is made on the thermohaline circulation whose sensitivity to orography has only be...