Air density 2.7 billion years ago limited to less than twice modern levels by fossil raindrop imprints

  title={Air density 2.7 billion years ago limited to less than twice modern levels by fossil raindrop imprints},
  author={Sanjoy M. Som and David C. Catling and Jelte P. Harnmeijer and Peter M. Polivka and Roger Buick},
According to the ‘Faint Young Sun’ paradox, during the late Archaean eon a Sun approximately 20% dimmer warmed the early Earth such that it had liquid water and a clement climate. Explanations for this phenomenon have invoked a denser atmosphere that provided warmth by nitrogen pressure broadening or enhanced greenhouse gas concentrations. Such solutions are allowed by geochemical studies and numerical investigations that place approximate concentration limits on Archaean atmospheric gases… 

Geoscience: Fossil raindrops and ancient air

An analysis of fossil imprints of ancient raindrops suggests that the density of the atmosphere 2.7 billion years ago was much the same as that today. This result casts fresh light on a long-standing

Hydrogen-Nitrogen Greenhouse Warming in Earth's Early Atmosphere

It is shown that with an atmospheric composition consistent with the most recent constraints, the early Earth would have been significantly warmed by H2-N2 collision–induced absorption, key to warming the atmosphere of theEarly Earth.

The Archean atmosphere

The Archean eon data imply that substantial loss of hydrogen oxidized the Earth, and detailed understanding of the coevolving solid Earth, biosphere, and atmosphere remains elusive, however.

Examining the role of varying surface pressure in the climate of early Earth

Abstract. During the Archean Eon in 2.7 billion years ago, solar luminosity was about 75 % of the present-day level, but the surface temperature was suggested to similar to or even higher than

Atmospheric CO2 levels from 2.7 billion years ago inferred from micrometeorite oxidation

This model reproduces the observed oxidation state of micrometeorites at 2.7 Ga for an estimated atmospheric CO2 concentration of >70% by volume, which would help resolve how the Late Archean Earth remained warm when the young Sun was ~20% fainter.

Ancient micrometeorites suggestive of an oxygen-rich Archaean upper atmosphere

The model of atmospheric micrometeorite oxidation suggests that Archaean upper-atmosphere oxygen concentrations may have been close to those of the present-day Earth, and that the ratio of oxygen to carbon monoxide was sufficiently high to prevent noticeable inhibition of oxidation by Carbon monoxide.

Is the Faint Young Sun Problem for Earth Solved?

Stellar evolution models predict that the solar luminosity was lower in the past, typically 20-25% lower during the Archean (3.8-2.5 Ga). Despite the fainter Sun, there is strong evidence for the

Exploring the faint young Sun problem and the possible climates of the Archean Earth with a 3‐D GCM

Different solutions have been proposed to solve the “faint young Sun problem,” defined by the fact that the Earth was not fully frozen during the Archean despite the fainter Sun. Most previous



Nitrogen-enhanced greenhouse warming on early Earth

Early in Earth’s history, the Sun provided less energy to the Earth than it does today. However, the Earth was not permanently glaciated, an apparent contradiction known as the faint young Sun

Atmospheric composition and climate on the early Earth

  • J. KastingM. Howard
  • Geology, Geography
    Philosophical Transactions of the Royal Society B: Biological Sciences
  • 2006
It is argued, following others, that this interpretation of oxygen isotope data is incorrect—the same data can be explained via a change in isotopic composition of seawater with time, which implies that the early Earth was warm, not hot.

A revised, hazy methane greenhouse for the Archean Earth.

Geological and biological evidence suggests that Earth was warm during most of its early history, despite the fainter young Sun. Upper bounds on the atmospheric CO2 concentration in the Late

Theoretical constraints on oxygen and carbon dioxide concentrations in the Precambrian atmosphere.

  • J. Kasting
  • Environmental Science
    Precambrian research
  • 1987

Oxygen and hydrogen isotope evidence for a temperate climate 3.42 billion years ago

The results indicate that the Palaeoarchaean ocean was isotopically depleted relative to the modern ocean and far cooler than previously thought.

Dating the rise of atmospheric oxygen

It is found that syngenetic pyrite is present in organic-rich shales of the 2.32-Gyr-old Rooihoogte and Timeball Hill formations, South Africa, indicating that atmospheric oxygen was present at significant levels during the deposition of these units.

Evidence from massive siderite beds for a CO2-rich atmosphere before ~ 1.8 billion years ago

It is generally thought that, in order to compensate for lower solar flux and maintain liquid oceans on the early Earth, methane must have been an important greenhouse gas before ∼2.2 billion years

Biogeochemical modelling of the rise in atmospheric oxygen

Understanding the evolution of atmospheric molecular oxygen levels is a fundamental unsolved problem in Earth's history. We develop a quantitative biogeochemical model that simulates the