On 24/03/19 10:25, Zenaan Harkness wrote:
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.
eh? The measuring equipment works fine. The overall measured - not estimated, measured - change is from 280 ppm to 411 ppm. That is easily measurable, and measured. The global aggregate %ge change is 46.8% increase over 170 years. Nearly half as much again. The margins of error of the %ge change are around 1 part in 1,000. So it's pretty accurate - not 45%, not 47%, but 46.odd%. Estimates for more recent periods are accurate to about 1 part in 10,000. Pretty darn accurate. There is no accuracy problem.
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.
Greenhouse theory is simply the prediction that glass, increased CO2 etc levels etc increase the reflection of long-wave IR back to the ground, so decreasing heat lost into space. And guess what, it both works and is directly measurable. One lesser-known prediction of greenhouse theory is that the present average temperature of the earth should be around 15 C - if there was no global warming, the average temperature would be -18 C. And yes, greenhouse theory itself is consensus. Some details of what is happening now are a little fuzzy, and extrapolation quickly gets lost because the earth is so complex and politics, but overall we are slowly getting there.
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".
You are a bit out of date there. Consensus pretty much exists amongst non-conflicted scientists. Both those theories have some truth in them, but the first is irrelevant in view of the measured increase in CO2 levels, the second is misstated - agreed the sun has a major long-term influence, yes, but not the recent short term influence seen in practice.
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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
It's your number .. and irrelevant anyway. Fact: CO2 levels have increased, measurably, from 280 to 411 ppm, in the modern era. Fact: This happened too fast to have happened naturally without signs we would have clearly seen, so it must be man-made.
flapping in the wind about compound exponential fear mongering ...
No evil exponentials need get involved. Suppose there is 400 tons in the atmosphere, nature produces 100 tons per year, nature removes 100 tons per year. Now if man adds 3 tons per year for a hundred years, without any increase in the removal by nature there will be 300 extra tons in the atmosphere. In reality nature will take up some of the slack, so lets say the increase is only 150 tons. Or, to put it in real numbers; in 1850 there were 1,480 Gt of CO2 in the atmosphere. Today there is 2,166 Gt, an increase of 686 Gt. Estimated human CO2 release in that period, based on the amount of coal, gas and oil burnt, is about 1,340 Gt. So nature has absorbed an extra 654 Gt. The rate at which nature recycled CO2 isn't immediately relevant, but it is estimated at about 350 Gt/y.
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.
We are. But that part of the cycle causes change at the rate of about 50 ppm total over several thousand years, not 131 ppm over 170 years. The recent rate of change is well outside anything in the recent fossil record.
You and I both are likely just parroting assumptions based on preferred viewpoitns, rather than science.
No. What assumptions? I guess I assume the measured increase in CO2 is real, and that by greenhouse theory increased atmospheric CO2 decreases global cooling - both of these are, or should be, non-contentious.
And on that basis, I prefer my viewpoints over yours as "more grounded in science" <chuckle>
Normally I wouldn't care any - but this sort of wilful stupidity could end up killing everyone.
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.
Eh? It's the simplest of back-of-an-envelope, measure-it-yourself stuff. Back of an envelope to calculate the thickness of CO2, which I just did (I also calculated the Gt numbers above, indeed I calculate most numbers when I give them - keeps me honest, keeps me in practice, and gives me a better overview). Measure-it-yourself, well if I must, but it's easier just to look up the long-wave IR absorbance spectrum of CO2. Measuring long wavelength IR spectra in a gas is a bit unwieldy, I haven't done it in 45 years. Note that I haven't said anything about how significant today's levels are - mainly because I don't really know. But I am a little worried about the possibility of an end-Permian level extinction event. Or worse, end of all life on earth - the sun is hotter now. -- Peter Fairbrother