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. 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. Will increases in CO2 of this magnitude cause global warming? Well, greenhouse theory says it will. And it always has before.
--------------- 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, 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.
• 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. -- Peter Fairbrother ppm = parts per million, by weight