en.wikipedia.org/wiki/Greenhouse_and_icehouse_Earth
3 corrections found
Around the same geologic period of Snowball Earth (it is debated if it was the cause or the result of Snowball Earth), the Great Oxygenation Event (GOE) was occurring.
This mixes up events that were separated by roughly 1.7 billion years. The Great Oxygenation Event happened around 2.4 billion years ago, while the Cryogenian “Snowball Earth” episodes occurred much later, around 720–635 million years ago.
Full reasoning
The timing here is wrong by a very large margin.
- NASA Astrobiology states that the Great Oxidation/Oxygenation Event occurred around 2.4 billion years ago.
- NASA GISS places the Cryogenian Snowball Earth glaciations at roughly 850–635 million years ago (and specifically notes the last one ended around 635 million years ago).
Those dates are not "around the same geologic period"; they are separated by about 1.7 billion years.
A related NASA Astrobiology article also describes the Ediacaran (635–541 million years ago) as the interval after a Snowball Earth event and notes that it was followed by the Cambrian explosion, which is consistent with Snowball Earth being late Precambrian—not contemporaneous with the GOE.
3 sources
- Oxygen Production in Earth's Early Oceans Predates the Great Oxidation Event | NASA Astrobiology
It is widely accepted that around 2.4 billion years ago, the Earth's atmosphere underwent a dramatic change when oxygen levels rose sharply. Called the "Great Oxidation Event" (GOE)...
- "Snowball Earth" Might Have Been Slushy | NASA GISS
The last of these so-called "Snowball Earth" glaciations ended around 635 million years ago... In their simulations of the Cryogenian period (850-635 million years ago)...
- Piecing Together The Narrative of Evolution | NASA Astrobiology
Her specialty is the Ediacaran period some 635 to 541 million years ago. This transitional period came after a snowball Earth event and was followed by the Cambrian explosion...
Earth will likely phase into another interglacial period such as the Eemian
The Eemian was not a future interglacial; it was the last interglacial before the present Holocene. Under natural conditions, the next major transition after the current interglacial would be toward glaciation, not into the Eemian.
Full reasoning
This sentence gets the sequence of glacial cycles backwards.
- The Eemian is the last interglacial, dated by USGS to about 130,000 to 116,000 years ago.
- USGS also states that today we are living in the most recent interglacial, the Holocene.
- A Nature study on future glacial inception concludes that, even without human influence, the current interglacial would probably last for another 50,000 years before the next substantial glaciation—not that Earth would next "phase into" the Eemian or another interglacial directly.
So the Eemian is a past warm interval used as an analogue for today, not the climate state Earth is expected to enter next from the present interglacial.
3 sources
- Last interglacial climates | U.S. Geological Survey
The last interglacial... is arbitrarily dated to begin at approximately 130,000 yr B.P. and end at 116,000 yr B.P. with the onset of the early glacial unit MIS 5d. Approximately 127,000 yr ago the Eemian mixed forests were established in Europe.
- Sea Level and Climate | U.S. Geological Survey
Today we are living in the most recent interglacial, an interval that started about 10,000 years ago and is called the Holocene Epoch by geologists.
- Critical insolation-CO2 relation for diagnosing past and future glacial inception | Nature
...our analysis suggests that even in the absence of human perturbations no substantial build-up of ice sheets would occur within the next several thousand years and that the current interglacial would probably last for another 50,000 years.
which is close to today's levels
250 ppm is not close to today’s atmospheric CO2 level. NOAA reports atmospheric CO2 around 426 ppm in September 2026, and even preindustrial levels were about 270–280 ppm.
Full reasoning
The comparison to "today's levels" is inaccurate.
- NOAA's current Mauna Loa record shows atmospheric CO2 at 426.07 ppm in September 2026.
- NOAA also states that global average atmospheric CO2 in 2024 was 422.80 ppm.
- The same NOAA page notes that preindustrial CO2 was only about 270–280 ppm.
So 250 ppm is not close to present-day atmospheric CO2, and it is even below typical preindustrial levels.
2 sources
- Trends in CO2 - NOAA Global Monitoring Laboratory
Monthly Average Mauna Loa CO2 September 2026: 426.07 ppm ... September 2025: 424.37 ppm.
- Annual Greenhouse Gas Index (AGGI) - NOAA Global Monitoring Laboratory
NOAA's measurements show that the global abundance of atmospheric CO2 in the marine boundary layer reached 422.80 ± 0.10 ppm in 2024... Measurements of air in bubbles trapped in ice cores indicate that global average CO2 abundance was stable at between around 270 - 280 ppm ... around 1850.