On Sun, Mar 24, 2019 at 05:40:33AM +0000, Peter Fairbrother wrote:
On 21/03/19 09:21, Zenaan Harkness wrote:
Q1. What % of the air is CO2?
… CO2 is less than a mere four 100ths of 1%! As a decimal it is 0.038%. As a fraction it is 1/27 th of 1%. (Measurements for CO2 vary from one source to another from 0.036% - 0.039% due to the difficulty in measuring such a small quantity and due to changes in wind direction e.g. whether the air flow is from an industrialized region or a volcanic emission etc)
i.e. the measured concentration changes if the air flow is from an industrialized region
So even according to you mankind's contribution is measurable.
Local delta's are measurable "at coordinate", which can be fed into any number of computer models to estimate aggregates per area or per globe. So the global "man-made" CO2 contribution delta is estimatable, even though the global aggregate % change is not measurable, due to margins of error and the limits and errors of measuring equipment. The measurability is not a contentious point, so little use in making this a contention. Seek truth in the presentations of each, and we find truth in one another. This is perhaps the useful place to start.
Getting real, NOAA measure global average CO2 to about five figures of accuracy - presently it is 411.75 ppm. People who use different methods sometimes argue about the last figure, so let's say it is routinely measured accurate to maybe 4.5 digits.
Over the million years before 1900 CO2 global average levels hovered around 220 ppm, and never exceeded 300 ppm. In the last few 100 years the level has gone from 280 ppm to 411 ppm.
Which is absolutely fantastic for life on this planet, since at 180ppm and below, most plants die, along with their "high up" food chains... Rumour has it we should now be good for at least a few thousand years from now, even if man goes "fully electric, man, fully electric" overnight.
Will increases in CO2 of this magnitude cause global warming? Well, greenhouse theory says it will. And it always has before.
Greenhouse theory, is anything but concensus. To imply otherwise is disingenuous. Some scientific theory has it that CO2 is a product primarily of the quanta of plant life, plus the temperature of the oceans (and thus oceanic absorption vis a vis release, of CO2). Other scientific theory has it that almost everything is entirely driven by the Sun. There is no concensus that atmospheric CO2 is the cause, and not the consequence of, "global warming" or rather, "global heat levels due to solar, and tectonic, activity".
--------------- Q3. What % of CO2 do humans produce?
… Nature produces nearly all of it. Humans produce only 3%.
You are looking at it the wrong way.
Though I personally doubt it, it may be that humans only produce 3% as much CO2 as per year as nature does. But an increase of 3% per year,
"increase per year" is vastly different to "total over all modern time, i.e. industrial revolution" - someone would need to look at the source for this 3% number so that we can talk about it without wildly flapping in the wind about compound exponential fear mongering ...
if not compensated for, is 30% in ten years, or 300% in 100 years.
People may argue up and down about that, but the simple fact is that CO2 levels rose from 280 pm to 411 ppm over the last few 100 years. This is a man-made increase. There is no natural CO2 regulation process (other than major volcanism or fires, which did not happen) which could work that fast.
Which means that human activities have increased the amount of CO2 in the atmosphere by 32% over the last few 100 years.
Possibly, or possibly we're in a particularly "good for life" solar and tectonic "warming" cycle. You and I both are likely just parroting assumptions based on preferred viewpoitns, rather than science. And on that basis, I prefer my viewpoints over yours as "more grounded in science" <chuckle>
• It is true that CO2 can absorb heat a little faster than nitrogen and oxygen but it becomes no hotter because it cannot absorb anymore heat than there is available to the other gases.
Greenhouse theory has nothing to do with CO2 in the atmosphere getting hot.
The basic mechanism controlling the Earth's temperature is: the sun shines light and shortwave infrared on the ground. The ground absorbs them and gets warm. At night the heat from the warm ground is radiated into space as long wave infra-red.
CO2 interferes with this process because it reflects the outgoing long wave infra-red back towards the ground (it does not reflect the incoming short wave infrared.)
This may sound strange - how can only 400 ppm of CO2 reflect long wave IR? But if you think about it, 400 ppm of the 50 km tall atmosphere is roughly equivalent to a pound per square foot of the earth's surface - or travelling through 10 feet of CO2 at normal atmospheric pressure - enough for the beginnings of a mirror.
Need some hard science on that to make sense of anything other than our personally preferred assumptions... and not just computer models, but actual calculations which are peer reviewed and "generally agreed or at least not disputed by those who would" kind of science.