A Hazy Atmosphere on Early Earth

A Hazy Atmosphere on Early Earth

Most scientists think Earth’s early atmosphere looked similar to that of today—dominated by nitrogen and carbon dioxide, largely transparent, and having clouds scattered across the globe. This view contrasts with RTB’s model where Earth’s early atmosphere was translucent (rather than transparent) such that the Sun, Moon, and stars could not be seen regularly from Earth’s surface. One recent paper provides some evidence that supports RTB’s model.

And God said, “Let there be light,” and there was light…. And there was evening, and there was morning—the first day….
And God said, “Let there be lights in the vault of the sky to separate the day from the night, and let them serve as signs to mark sacred times, and days and years,… And there was evening, and there was morning—the fourth day. (Genesis 1:3, 5b; 1:14, 19)

RTB’s creation model takes these two miracles, on creation days one and four, as describing two different changes to the atmosphere. Day one saw a clearing of the atmosphere so that sunlight could now reach Earth’s surface. Day four brought a further clearing so that the objects providing the light could be seen from Earth’s surface. This interpretation means that between the two “days,” Earth’s atmosphere was hazy and/or cloudy like a rainy day (or a really smoggy day for those big city dwellers).

Most markers of Earth’s early atmosphere indicate that it consisted of carbon dioxide, water vapor, and nitrogen—similar to today’s atmosphere, minus the oxygen. If so, one would reasonably expect the atmosphere to look like it does today, with clouds scattered over the globe but otherwise clear skies. Yet one additional component on the early Earth may have led to a hazy, translucent atmosphere.

A team of scientists studying 2.65 billion-year-old geological features in South Africa found evidence that methane and other organic materials played an important role in the planet’s atmosphere prior to the great oxygenation event.1 Just like on Titan (one of Saturn’s moons) today, these organics likely produced a haze in the atmosphere that would have shielded Earth’s surface from a sizable amount of the Sun’s radiation. One outstanding question pertains to how much haze the organics would produce. In their search for an answer, the team found two stable states of methane concentrations—a higher one that produced a significant haze and a lower one that produced very little. The fact that methane exists in these two stable states leads to a plausible scenario that matches the RTB model.

Early in Earth’s history there was a larger methane concentration. Photosynthetic life was also present, which introduced more oxygen to the atmosphere. Though oxygen reacts with the methane, it also reacts with many other things throughout the planet’s atmosphere and interior. Consequently, early Earth would consume oxygen faster than it was produced; thus, preventing early atmospheric oxygen levels from rising. So simply having oxygen-producing life present on the planet wouldn’t have significantly lowered the methane concentration.

However, by about 2.5 billion years ago, Earth’s oxygen sinks had filled up and the atmospheric oxygen increased dramatically (during the great oxygenation event), causing the methane concentration level to drop and go from a hazy to a clear state. It remains in this clear state to the present day.

Although plausible, not enough scientific data exists to validate or falsify this scenario. Since the prevailing view of the early atmosphere stands in contrast to the RTB model, it represents a fruitful arena to test creation model predictions.

  1. Aubrey L. Zerkle et al., “A Bistable Organic-rich Atmosphere on the Neoarchaean Earth,” Nature Geoscience (published online March 18, 2012), doi:10.1038/ngeo1425, https://www.nature.com/ngeo/journal/vaop/ncurrent/abs/ngeo1425.html.