Comments on: Maybe not a greenhouse effect after all? https://habitablezone.com/2012/05/01/not-a-greenhouse-effect-at-all/ Fri, 03 Apr 2026 22:41:18 -0700 hourly 1 http://wordpress.org/?v=3.3.1 By: ER https://habitablezone.com/2012/05/01/not-a-greenhouse-effect-at-all/#comment-14633 ER Wed, 02 May 2012 03:44:21 +0000 http://habitablezone.com/?p=14563#comment-14633 What I find most disturbing is a rise in atmospheric CO2 of approximately 25% in a little over half a century. That's an awful lot in a very short time; its not what you'd expect from a geological process. What I find most disturbing is a rise in atmospheric CO2 of approximately 25% in a little over half a century. That’s an awful lot in a very short time; its not what you’d expect from a geological process.

]]> By: bowser https://habitablezone.com/2012/05/01/not-a-greenhouse-effect-at-all/#comment-14632 bowser Wed, 02 May 2012 03:43:11 +0000 http://habitablezone.com/?p=14563#comment-14632 http://www.youtube.com/watch?v=7n_m3q7XYz4 http://www.youtube.com/watch?v=7n_m3q7XYz4

]]> By: ER https://habitablezone.com/2012/05/01/not-a-greenhouse-effect-at-all/#comment-14631 ER Wed, 02 May 2012 03:34:55 +0000 http://habitablezone.com/?p=14563#comment-14631 ...may be that CO2 levels may not necessarily be hostile to marine life, but rapid changes may be. Also, extinctions may be caused by a variety of other events; impacts, vulcanism, tectonic activity, climate change from other causes,and so on. Its pretty clear there's not much we can do about these events, but they are probably only apparent over deep geological time (except for the impacts!). …may be that CO2 levels may not necessarily be hostile to marine life, but rapid changes may be. Also, extinctions may be caused by a variety of other events; impacts, vulcanism, tectonic activity, climate change from other causes,and so on. Its pretty clear there’s not much we can do about these events, but they are probably only apparent over deep geological time (except for the impacts!).

]]> By: ER https://habitablezone.com/2012/05/01/not-a-greenhouse-effect-at-all/#comment-14630 ER Wed, 02 May 2012 03:26:35 +0000 http://habitablezone.com/?p=14563#comment-14630 The first shellfish and corals evolved to survive in the CO2 levels that existed AT THE TIME THEY AROSE. The extinction occurred during a time of quickly changing acid levels that the organisms could not adapt to quickly enough: like the one we're undergoing now (unless some mechanism kicks in to turn it around). For that matter, the first marine life must have evolved when there was no free oxygen in the atmosphere at all, CO2 levels were through the roof and sea water acidity was very high. And note the spike in CO2 levels on that chart right around the time of the extinction event in the article. That is consistent with the article's conclusions. The general trend of CO2 levels since the Permian extinction event has been down. The trend over the last 60 years (the data coverage I linked to), has been climbing. Incidentally, CO2 dissolves in water to form a weak acid, it doesn't kill things outright, but it interferes with the formation of carbonates for shells. It doesn't have to kill everything, just interrupt the food chain to provoke an extinction. The excess carbon is removed from the water by limestone (CaCO3) formation. But calcium carbonate also dissolves in water, so an equilibrium is eventually reached. A sudden surge or shortage of CO2 can provoke change in the water's pH. This is what they think is killing the coral now. I'm only speculating, but I would bet that big dip in CO2 levels starting around -450Myr is due to the colonization of the land by plants. Multicellular life arose over half a billion years ago, about the time that CO2 curve was peaking, I'd wager. The first shellfish and corals evolved to survive in the CO2 levels that existed AT THE TIME THEY AROSE. The extinction occurred during a time of quickly changing acid levels that the organisms could not adapt to quickly enough: like the one we’re undergoing now (unless some mechanism kicks in to turn it around).

For that matter, the first marine life must have evolved when there was no free oxygen in the atmosphere at all, CO2 levels were through the roof and sea water acidity was very high. And note the spike in CO2 levels on that chart right around the time of the extinction event in the article. That is consistent with the article’s conclusions.

The general trend of CO2 levels since the Permian extinction event has been down. The trend over the last 60 years (the data coverage I linked to), has been climbing.

Incidentally, CO2 dissolves in water to form a weak acid, it doesn’t kill things outright, but it interferes with the formation of carbonates for shells. It doesn’t have to kill everything, just interrupt the food chain to provoke an extinction. The excess carbon is removed from the water by limestone (CaCO3) formation. But calcium carbonate also dissolves in water, so an equilibrium is eventually reached. A sudden surge or shortage of CO2 can provoke change in the water’s pH. This is what they think is killing the coral now.

I’m only speculating, but I would bet that big dip in CO2 levels starting around -450Myr is due to the colonization of the land by plants. Multicellular life arose over half a billion years ago, about the time that CO2 curve was peaking, I’d wager.

]]> By: TB https://habitablezone.com/2012/05/01/not-a-greenhouse-effect-at-all/#comment-14629 TB Wed, 02 May 2012 03:06:30 +0000 http://habitablezone.com/?p=14563#comment-14629 <p>The question is why these much higher CO2 levels didn't make the oceans a lot more hostile to life 500 million years ago than during the Great Extinction?</p> It's possible an expert on ancient climates and lifeforms has already figured this out, but it's a disconnection. <a href="http://en.wikipedia.org/wiki/Extinction_event" rel="nofollow">Here's something</a> on marine extinction events. <img src="http://upload.wikimedia.org/wikipedia/commons/thumb/0/06/Extinction_intensity.svg/320px-Extinction_intensity.svg.png" alt="" /> The graph shown on the website is labeled and explained. "P-Tr" is the event discussed in the original article. The question is why these much higher CO2 levels didn’t make the oceans a lot more hostile to life 500 million years ago than during the Great Extinction?

It’s possible an expert on ancient climates and lifeforms has already figured this out, but it’s a disconnection.

Here’s something on marine extinction events.

The graph shown on the website is labeled and explained. “P-Tr” is the event discussed in the original article.

]]> By: bowser https://habitablezone.com/2012/05/01/not-a-greenhouse-effect-at-all/#comment-14628 bowser Wed, 02 May 2012 02:50:54 +0000 http://habitablezone.com/?p=14563#comment-14628 And no human beings, cultures and civilizations existed then. And no human beings, cultures and civilizations existed then.

]]> By: TB https://habitablezone.com/2012/05/01/not-a-greenhouse-effect-at-all/#comment-14626 TB Wed, 02 May 2012 02:32:22 +0000 http://habitablezone.com/?p=14563#comment-14626 <p>Ancient CO2 levels</p> <a href="http://earthguide.ucsd.edu/virtualmuseum/climatechange2/07_1.shtml" rel="nofollow">Here.</a> On the scale on the left side of the chart, current levels would be about 1.3 <img src="http://earthguide.ucsd.edu/virtualmuseum/images/raw/CCC_Fig4_2_1.jpg" alt="CO2" /> The article explains where a lot of this stuff went to. The scientists may be correct, but they need to correlate this information into the theory too. The first shellfish and corals evolved between 500 and 550 million years ago. Ancient CO2 levels

Here.

On the scale on the left side of the chart, current levels would be about 1.3

CO2

The article explains where a lot of this stuff went to.

The scientists may be correct, but they need to correlate this information into the theory too. The first shellfish and corals evolved between 500 and 550 million years ago.

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