Human CO2 will Destroy our Planet!…or Will It?

Vern Scott
6 min readMar 18, 2021

I had more or less accepted on scientific “faith” that CO2 produced by humans was contributing to a potential runaway warming problem. Further research reveals that while this is true in the short term (just witness the rate of recent CO2 rise, glacial melting and extreme weather), long term “runaway” CO2 warming may be a remote possibility, mostly due to the Milankovitch Cycle (changes in the earth’s orbit and tilt angle). Are the resulting controversies a politicization of climate science at work?

Glaciers are now melting and CO2 is up, but CO2 gobbling glaciation will reoccur due to the Milankovitch Cycle

I feel much better about the earth’s future after today’s research, especially after reading about how we survived the Cretaceous Thermal Maximum 90 million years ago (when temperatures rose 14 degrees F and CO2 was 1,000 ppm, only to be moderated by glaciation and possibly plate tectonics). The main thing is, this has happened before and apparently Mother Earth has ways to offset the damage (CO2 was even 9,000 ppm 500 million years ago!). The interesting thing is how much uncertainty there is on the whys and hows of both previous CO2 increases and decreases, which begins to make one feel less sure of the climate science theories of today. There has definitely been a rapid CO2 increase during the industrial period, (250 ppm to 410 ppm today), but just how bad is this? Is it a runaway problem (probably not, since there tends to be moderating forces). Do the resultant high temperatures create disastrous results? Well yes and no, yes obviously in terms of rising sea levels, melting glaciers, and extreme weather events, but no, not anything the earth hasn’t seen before or cannot apparently deal with. It is certainly a test of our human resilience, but then resilience and adaptation is more or less the history of our species. (Bice,Norris,2002),(Mulhern,2020)

Let’s begin with the aforementioned Cretaceous Thermal Maximum, when CO2 was 2–1/2 times higher than today, and the earth was HOT (no polar ice, oceans perhaps 90 degrees F!). Scientists believe that these conditions were created by massive methane releases, perhaps related to receding of polar ice, plus volcanic activity and tectonic movements (this was also when “pangaea” was separating into modern day continents). At this point, it is interesting to note that scientists are not sure whether tectonic movement CREATES CO2 or ABSORBS CO2, or maybe I’m misunderstanding. It might be said that new ocean pathways and currents (such as those created by continental drifts) may tend to absorb CO2 (due to movement of colder water to the surface, which more easily dissolves CO2). It may also be said that rifts or upwelling in the earth’s crusts may tend to release CO2, due to the escaping of heat and previously trapped gases. In any case, the dire warming events of the Cretaceous were soon moderated. (Scott,Lindsey,2020),(Andrews,2016),(Huber,McLeod,Watkins,Coffin,2018)

Dinosaurs thrived during the extremely hot Cretaceous Thermal Maximum 90 million years ago, when CO2 was over 1,000 ppm

Now let’s examine the main causes of glaciation, variations in the earth’s orbit and tilt angle, called Milankovitch Cycles. Roughly every 100,000 years, the Earth’s orbit is made more extreme by the gravitational pull of the outer planets (chiefly Jupiter and Saturn), which makes us colder in Winters. In addition, the Earth’s axis has a tilt angle that varies from 22.1 to 24.5 degrees (and back), at a 41,000 year interval. There are other orbital, tilt, and “wobble” effects, astronomically understood but not completely understood with respect to climate change. The best evidence is that during the last 1 million years, glaciation has followed the 100,000 year cycle, and prior to that the 41,000 year cycle. Thus, though the Earth’s orbit is the dominant predictor of glaciation, there may have been some event 1 million years ago that made it more so. Also, scientists don’t completely understand the interaction between glaciation and CO2 absorption. It is believed that glaciation absorbs CO2, since again, it is known that CO2 dissolves more readily in colder water. It is also believed that ice caps may contain methane release, and that iron blowing into seas from drier continents encourages CO2 absorbing phytoplankton growth (which sends CO2 to the ocean bottom). Ocean “upwelling” (more common in coastal areas or those affected by wind and currents), initially releases CO2, but cools surface water and feeds phytoplankton, ultimately reducing CO2. Ice-Albedo Feedback (in which growing ice caps reflect solar radiation and further cool the planet, or the reverse-which appears to be happening now) is another major warming/cooling factor. Research into all these areas are growing and evolving, with new instrumentation and data creating ever-more theories. (Buis,2020),(Campisano,2012),(Riebeek,2008),(Ness-Cohn,2019)

The breakup of Panagaea during the Cretaceous (with associated tectonic movements, volcanic activity, escaping gases creating CO2, and new ocean current forming and iron-laden dust diminishing CO2 )

This information raises the question “will there ever be a danger of a runaway greenhouse effect”, which is relevant since industrial CO2 release has led to warming which has led to ice cap melting, which has led to natural methane release…and more warming. At this point, many bring up the planet Venus, which was known to have had water 3.9 billion years ago. It is believed that the Sun grew brighter and hotter at that time, vaporizing Venus’ water and destroying its atmosphere (in a runaway fashion, since more CO2 made the planet hotter, which created more CO2, etc). Inevitably, the same will happen to us, but not for another 1.5 billion years or so (enough time to move to another planet?). There seems to be several CO2 moderating factors that would offset a “runaway greenhouse effect”, including glaciation, ocean upwelling, and phytoplankton for starters (receding glaciers free up minerals that become phytoplankton food). After all, we are still in a very good position relative to the Sun, much better than Venus or Mars, not too hot or too cold, certainly able to moderate our comfort levels by moving to a better place (indeed, this is again the history of humanity…relocating according to the climate). A potential wild card may be human-caused plastics, fertilizers, chemicals, etc that could negatively effect phytoplankton. Though a “runaway greenhouse” scenario may be remote, I guess erring on the side of caution would include a phaseout of fossil fuel burning and increase of human-fostered plant growth (not to mention wise-use of manufactured chemicals). Fossil fuel phase out, conveniently, is also practical for reasons of energy efficiency and economy. By the way, seeding the oceans with iron to stimulate phytoplankton seems on the face of things an easy way to decrease CO2 (but it may be more problematic than we initially realize). (,2019),(Linnert,Robinson,Lees,Bown,Perez-Rodriguez,et al,2014),(Carlowicz,2004),(,2020)

Variations in the Earth’s orbit and tilt angle create glacial, or “Milankovitch” cycles

Conclusions? Well on the political side, the right-wingers seem to have an inordinate love of fossil fuel and denial of climate change data, which likely reveals their love of short term oil profits and hatred of environmental cleanup. But the left wing seems a bit chicken-littlish on the subject (and one wonders if some of this is driven by a vegan/solar/tree hugging orthodoxy). After all, CO2 was increasing before the industrial age and has been sky-high at times before humans existed, yet the planet survived. Don’t look for us to become Venus or Mars any time soon (but remember that eventually, we WILL become Venus, in about 1.5 billion years when the Sun gets bigger/brighter). We seem to have been gifted with a planet that moderates CO2 levels with periodic, orbit affected glaciation, among other things. For the short-term (until we can figure out how to reign in CO2), we can expect more forest fires, stronger hurricanes and storms, more flooding, and more drought, all of which will force us to relocate (probably to more northerly latitudes, away from the coasts). The best reasons to abandon fossil fuels may be the increasing costs of extracting them (relative to solar, which is getting cheaper), their inefficiencies, plus the costs of their cleanup. The evidence implies that fossil fuels definitely contribute to climate change, but are not solely responsible, nor is the earth not prepared to moderate their CO2 contribution. (Sundermier,2018)

Enjoy these other Vern Scott Energy and Transportation Articles:

What a National Infrastructure Upgrade Should Be

Energy Efficiency, Not Warming, will Sell Renewables

Fighting Cow Flatulence

Affordable 3D Printed Structures

Who Will Invent the Catalytic Converter of the Global Warming Age?

The Far-Off Future of Renewables



Vern Scott

Scott lives in the SF Bay Area and writes confidently about Engineering, History, Politics, and Health