English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The early Earth's environment is controversial. Climatic estimates range fromhot to glacial, and inferred marine pH spans strongly alkaline to acidic.Better understanding of early climate and ocean chemistry would improve ourknowledge of the origin of life and its coevolution with the environment. Here,we use a geological carbon cycle model with ocean chemistry to calculateself-consistent histories of climate and ocean pH. Our carbon cycle modelincludes an empirically justified temperature and pH dependence of seafloorweathering, allowing the relative importance of continental and seafloorweathering to be evaluated. We find that the Archean climate was likelytemperate (0-50 {\deg}C) due to the combined negative feedbacks of continentaland seafloor weathering. Ocean pH evolves monotonically from 6.6 (+0.6,-0.4)(2{\sigma}) at 4.0 Ga to 7.0 (+0.7,-0.5) (2{\sigma}) at the Archean-Proterozoicboundary, and to 7.9 (+0.1,-0.2) (2{\sigma}) at the Proterozoic-Phanerozoicboundary. This evolution is driven by the secular decline of pCO2, which inturn is a consequence of increasing solar luminosity, but is moderated bycarbonate alkalinity delivered from continental and seafloor weathering.Archean seafloor weathering may have been a comparable carbon sink tocontinental weathering, but is less dominant than previously assumed, and wouldnot have induced global glaciation. We show how these conclusions are robust toa wide range of scenarios for continental growth, internal heat flow evolutionand outgassing history, greenhouse gas abundances, and changes in the bioticenhancement of weathering.

Constraining the climate and ocean pH of the early Earth with a geological carbon cycle model