Atmospheric CO₂ over the Past 66 Million Years from Marine Archives

Annual Review of Earth and Planetary Sciences, Год журнала: 2021, Номер 49(1), С. 609 - 641

Опубликована: Март 23, 2021

Throughout Earth's history, CO 2 is thought to have exerted a fundamental control on environmental change. Here we review and revise reconstructions from boron isotopes in carbonates carbon organic matter over the Cenozoic—the past 66 million years. We find close coupling between climate throughout Cenozoic, with peak levels of ∼1,500 ppm Eocene greenhouse, decreasing ∼500 Miocene, falling further into ice age world Plio–Pleistocene. Around two-thirds Cenozoic drawdown explained by an increase ratio ocean alkalinity dissolved inorganic carbon, likely linked change balance weathering outgassing, remaining one-third due changing temperature major ion composition. Earth system sensitivity explored may vary different time intervals. The record highlights truly geological scale anthropogenic change: Current were last seen around 3 years ago, cuts emissions are required prevent return Miocene or coming century. ▪ Myr alkenones reviewed re-evaluated. estimates proxies show agreement, yielding consistent picture evolution ocean-atmosphere Cenozoic. coupled Myr, providing broad constraints sensitivity. Twenty-first-century potential not since much warmer climates distant past.

Язык: Английский

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Framing, Context, and Methods

Cambridge University Press eBooks, Год журнала: 2023, Номер unknown, С. 147 - 286

Опубликована: Июнь 29, 2023

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Язык: Английский

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The Rising Threat of Atmospheric CO2: A Review on the Causes, Impacts, and Mitigation Strategies

Environments, Год журнала: 2023, Номер 10(4), С. 66 - 66

Опубликована: Апрель 14, 2023

The increasing levels of carbon dioxide (CO2) in the atmosphere have become a major environmental challenge due to their contribution global warming. primary drivers increase atmospheric CO2 concentrations are combustion fossil fuels, deforestation, agricultural practices, or production cement, which play significant role concentration atmosphere. However, efforts being made mitigate negative effects emissions, including capture and storage (CCS) technologies that aim from industrial processes store it underground geological formations. Methane, another potent greenhouse gas, is contributor climate change mainly produced by activities such as livestock farming rice cultivation. To address this, sustainable reducing meat consumption adopting climate-smart techniques, crucial. Ultimately, future can be secured for planet generations implementing effective measures, use energy sources, improvements efficiency, responsible land emissions both methane.

Язык: Английский

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Human impacts outpace natural processes in the Amazon

Science, Год журнала: 2023, Номер 379(6630)

Опубликована: Янв. 26, 2023

Amazonian environments are being degraded by modern industrial and agricultural activities at a pace far above anything previously known, imperiling its vast biodiversity reserves globally important ecosystem services. The most substantial threats come from regional deforestation, because of export market demands, global climate change. Amazon is currently perched to transition rapidly largely forested nonforested landscape. These changes happening much too for species, peoples, ecosystems respond adaptively. Policies prevent the worst outcomes known must be enacted immediately. We now need political will leadership act on this information. To fail biosphere, we our peril.

Язык: Английский

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Revisiting the Holocene global temperature conundrum

Nature, Год журнала: 2023, Номер 614(7948), С. 425 - 435

Опубликована: Фев. 15, 2023

Язык: Английский

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Atomic-level insights into surface engineering of semiconductors for photocatalytic CO2 reduction

Journal of Energy Chemistry, Год журнала: 2021, Номер 67, С. 309 - 341

Опубликована: Окт. 25, 2021

Photocatalytic conversion of CO2 into solar fuels provides a bright route for the green and sustainable development human society. However, realization efficient photocatalytic reduction reaction (CO2RR) is still challenging owing to sluggish kinetics or unfavorable thermodynamics basic chemical processes CO2RR, such as adsorption, activation, product desorption. To overcome these shortcomings, recent works have demonstrated that surface engineering semiconductors, introducing vacancy, doping, cocatalyst loading, serves effective promising strategies improved CO2RR with high activity selectivity. The essential reason lies in activation pathways can be optimized regulated through reconstruction atomic electronic structures. Herein, this review, we focus on research advances about rational design semiconductor CO2RR. selectivity will reviewed. In addition, theoretical calculations along situ characterization techniques spotlight clarify process. aim review provide deep understanding guidance semiconductors

Язык: Английский

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Phylogenomic analyses highlight innovation and introgression in the continental radiations of Fagaceae across the Northern Hemisphere

Nature Communications, Год журнала: 2022, Номер 13(1)

Опубликована: Март 14, 2022

Northern Hemisphere forests changed drastically in the early Eocene with diversification of oak family (Fagaceae). Cooling climates over next 20 million years fostered spread temperate biomes that became increasingly dominated by oaks and their chestnut relatives. Here we use phylogenomic analyses nuclear plastid genomes to investigate timing pattern major macroevolutionary events ancient genome-wide signatures hybridization across Fagaceae. Innovation related seed dispersal is implicated triggering waves continental radiations beginning rapid lineages resulting unparalleled transformation forest dynamics within 15 following K-Pg extinction. We detect introgression at multiple time scales, including predating origination genus-level diversity. As moved into newly available habitats Miocene, secondary contact between previously isolated species occurred. This resulted adaptive introgression, which may have further amplified white Eurasia.

Язык: Английский

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Spatial patterns of climate change across the Paleocene–Eocene Thermal Maximum

Proceedings of the National Academy of Sciences, Год журнала: 2022, Номер 119(42)

Опубликована: Окт. 10, 2022

The Paleocene–Eocene Thermal Maximum (PETM; 56 Ma) is one of our best geological analogs for understanding climate dynamics in a “greenhouse” world. However, proxy data representing the event are only available from select marine and terrestrial sedimentary sequences that unevenly distributed across Earth’s surface, limiting view spatial patterns change. Here, we use paleoclimate assimilation (DA) to combine model information create spatially complete reconstruction PETM state precedes it (“PETM-DA”). Our data-constrained results support strong polar amplification, which absence an extensive cryosphere, related temperature feedbacks loss seasonal snow on land. response hydrological cycle warming consists narrowing Intertropical Convergence Zone, off-equatorial drying, intensification monsoons winter storm tracks. Many these features also seen simulations future change under increasing anthropogenic emissions. Since PETM-DA yields estimate surface air temperature, rigorous global mean (5.6 ∘ C; 5.4 C 5.9 C, 95% CI) can be used calculate equilibrium sensitivity (ECS). We find ECS was 6.5 (5.7 7.4 CI), much higher than present-day range. This supports increases substantially when greenhouse gas concentrations high.

Язык: Английский

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Global production patterns: Understanding the relationship between greenhouse gas emissions, agriculture greening and climate variability

Environmental Research, Год журнала: 2023, Номер 245, С. 118049 - 118049

Опубликована: Дек. 31, 2023

Язык: Английский

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Assessment of Equilibrium Climate Sensitivity of the Community Earth System Model Version 2 Through Simulation of the Last Glacial Maximum

Geophysical Research Letters, Год журнала: 2021, Номер 48(3)

Опубликована: Янв. 15, 2021

Abstract The upper end of the equilibrium climate sensitivity (ECS) has increased substantially in latest Coupled Model Intercomparison Projects phase 6 with eight models (as this writing) reporting an ECS > 5°C. Community Earth System version 2 (CESM2) is one such high‐ECS model. Here we perform paleoclimate simulations Last Glacial Maximum (LGM) using CESM2 to examine whether its high realistic. We find that simulated LGM global mean temperature decrease exceeds 11°C, greater than both cooling estimated from proxies and by earlier model (CESM1). large attributed a strong shortwave cloud feedback newest atmosphere Our results indicate incompatible constraints projected future warming CESM2, similarly ECS, thus likely too large.

Язык: Английский

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