With that difference in atmospheric mass, and the fact that Venus’ atmosphere is mostly CO2, while our atmosphere is mostly Nitrogen, you really cannot compare the two planets in an argument about global warming.

The question is, would a complete elimination of all human produced CO2 dramatically alter the course? We should expect the growth in global CO2 to slow by the same amount of human produced CO2, but would natural sources continue to increase atmospheric CO2 levels?

With all human derived CO2 being eliminated in this scenario, I suspect we would still see a continued rise in atmospheric CO2 due to the naturally produced CO2.

Don’t buy the exponential rise in CO2 concentrations statistically associated with the exponential burning of fossil fuels. Being trained in math you will find that a segment of a sign wave will give you a better fit of the Mauna Loa data than an exponential curve. First, factor out the seasonal cycle. Then fit the data to sine(2*PI*years/a+b), where a is the cycle length in years and b positions the cycle. Use trial and error for a and b to maximize R square. Hint, start with “a” at 350 and vary “b” to maximize R square. then change “a” and repeat. Continue the process until you have found the maximum. This is a natural cycle that can be projected into the future. I predict that CO2 concentrations will continue to rise but at a slower rate and max out in the last half of this century between 500ppm and 600ppm.

CO2 increase has a logarithmic affect on the increase in temperature:
http://www.junkscience.com/Greenhouse/index.html

But as the author carefully is pointing out, the increase in CO2 may be exponential. That might mean a nearly linear (more or less) increase in temperatures, should the co2 increase continue exponentially.

As a skeptic, I salute the logic in this blog. But we cannot ignore logic from any source simply because of its source. Even should the “skeptics” be “deniers” who have no knowledge or degree (I’m a trained mathemetician, but not a climate scientist).

So where does this leave us? If more CO2 is being produced than can be absorbed by the Earth, and it increases exponentially, we will have negative affects. At the very least, if we reach 2000 ppm of CO2, it will make it difficult to breathe and we will have past the point where plants are helped by having more co2. That would truly be a runaway effect, if plants could no longer efficiently absorb co2, and it became difficult to breathe. But the temperature would still only have raised a few degrees.

In other words, exponential CO2 increase may cause huge problems even if global warming is overstated.

Based on your comment,it seems you have bought into an agenda that has blinded you from seeking scientific truths. I believe I am a pretty good environmental scientist having done research in EPA since it’s beginning until I retired eighteen years ago. One reason I retired early was because objective research was being side tracted for political purposes. This year EPA’s endangerment findings is the grave marker for objectivity at an agency that once had a reputation for good science. http://www.carlineconomics.com/. I believe Mike has a better understanding of how it really is than you do. I probably know more about science and math than Mike. Read my presentation http://www.kidswincom.net/climate.pdf. To check on my credentials, google “Fred H. Haynie” with +climate,or +statistics, or +economics,or +corrosion, or +thermodynamics. Other publications can be found with “Fred Haynie” but there are other Fred Haynies.

“However, scientists believe Venus did experience a global runaway greenhouse effect about 3 billion to 4 billion years ago.”

is scientific evidence of any relevance to climate change on Earth.

It may well be true that too much CO2 is bad for life on earth. Inarguably, too little CO2 is even worse. How does this lead you to some idea of the optimal concentration?

Mathematical modeling is fundamental to all good science. The math part is relatively easy. But you can fit curves to data in so many ways that you need a reason to believe that the fitted curve is of any value in extrapolation.

The honest way to do this is to run experiments which test the validity of projections made from the fitted curves. In physics and chemistry, millions of such experiments have been done in an attempt to contradict proposed models. Only a few such models can withstand this pressure. Even then, the scientist continues to probe for inconsistencies.

This CO2 modeling nonsense is science at its worst. You take a set of data. You make some random observation like “population grows exponentially” (it does not) Then you reason that CO2 is related to population (with no evidence as to how). There is no attempt to test with out-of-sample data.

In the background is a political agenda to limit economic growth and increase dictatorial poweres in the hands of a few experts. The correlations asserted between CO2 concentration and climate are laughable, even as pure math.

Maybe simple artificial examples presented honestly would be better for students than to follow the latest pop science craze. I do agree with the comment “children should be scared”…but not of climate change.