Superfact 91: Without greenhouse gases, the Earth’s average surface temperature would drop from the current 15 Celsius (59 Fahrenheit) to approximately -18 Celsius (0 Fahrenheit), which is an average temperature drop of 33 degrees Celsius. If you removed carbon dioxide from the atmosphere but let the other greenhouse gases stay the drop would be 30 degrees Celsius. In both cases most of the planet would freeze. This is referred to as snowball Earth.
Our planet is much warmer than it otherwise would be because of greenhouse gases. Carbon dioxide, or CO2, is the most important of the greenhouse gases. We are rapidly warming the atmosphere with our carbon dioxide emissions as explained by these articles from NASA and NOAA. If we did the opposite and removed CO2 from the atmosphere we would be cooling the atmosphere. As mentioned, if we removed all greenhouse gases from the atmosphere the planet’s average temperature would drop by 33 degrees Celsius and this NASA article claims it would take 50 years to reach that temperature.
If we removed only carbon dioxide and let all the other greenhouse gases remain, we would get an almost as big temperature drop of 30 degrees Celsius according to the calculations done by this article. Some of you may know that water vapor provides a larger portion of the warming than CO2. In fact, 75% of the greenhouse effect is caused by water vapor and clouds. This seems contradictory. However, when the atmosphere cools, the water vapor will rain out of the atmosphere unlike CO2. Basically, water vapor will adjust to the temperature whilst CO2 is forcing the temperature. It is crucial to understand this difference. That is why CO2 is the most important greenhouse gas. In summary, we need just the right amount of CO2 for a healthy climate.
I consider this a super fact because it is true, it is an important fact, and I believe it is a surprising fact to many, especially those who doubt carbon dioxide’s importance to the global warming we are experiencing. I called it global warming but whether you call it global warming, climate change, or climate disruption, we are talking about the same thing.
Snowball Earth
Scientists believe there have been at least two major “Snowball Earth” events between 720 and 635 million years ago where ice and snow covered nearly the entire planet. These snowball earth events were triggered by natural events, likely a plunge in sunlight, followed by a plunge in carbon dioxide not entering the atmosphere, and amplified by sunlight reflecting back into space. All three effects made Earth cooler. The recent ice ages were likely caused primarily by earth’s orbital cycles. Climate changed in the past due to natural phenomena, but that does not mean that the current very rapid warming (rapid geologically speaking) is natural.
If you want to understand why we can be so sure that it is our CO2 emissions that is causing the current global warming, not the sun, not volcanoes, not orbital cycles, and not another natural process, please check out the list of evidence in the second part of this post “Global Warming is Happening and is Caused by us”.
Hothouse Venus
The opposite of snowball Earth is hot Venus. Venus is the hottest planet in the solar system due to an extreme runaway greenhouse effect. Surface temperatures are averaging around 465 degrees Celsius (870 degrees Fahrenheit). The thick atmosphere of Venus is composed primarily of carbon dioxide with clouds of sulfuric acid. This causes a greenhouse effect that traps heat.
Despite the fact that Mercury is much closer to the sun (58 million kilometers versus 108 million kilometers) and receives nearly four times as much sunlight per unit area than Venus, Mercury is on average much cooler. The reason is that Mercury’s atmosphere is thin and without a greenhouse effect.
The YouTube video below from NASA explains the greenhouse effect on Venus. It is just one minute long.
To see the Other Super Facts click here
Super Facts 
Very interesting post, Thomas. I think I’ll just stay on Earth as long as possible.
LikeLike
A very important super fact post, Thomas. Thank you very much. We should be taking much better care of our planet.
LikeLike