On September 7, 2019 at 11:46, Anthony said...
1) if everyone agrees it is not 100% geogenic then does it matter really matter if it is 5% man made or 95% man made (don't get me wrong if it is 5% it means we have a harder job to do but isn't it still better to minimise that 5% or what ever % you feel is right?)
2) also the issue of anthropogenic and geogenic is that the two are not necessarily distinguishable for example the permafrost has a lot of global warming gases trapped in it but because it is frozen they are trapped. Now because of global warming more of more of the permafrost is not permafrost any more and the thaw means those gases are released to exacerbate the problem. Would it be fair to categorize it as natural if it was not an issue for the centuries it remained frozen?
3) it is not just CO2 it takes center stage because in essence it is the easiest to work with and it affects health and literally kills people.
The planet is warming, CO
2 is a greenhouse gas, atmospheric CO
2 content has increased, ergo CO
2 must be the cause. The problem with such a simplistic argument, however, is that it completely ignores historical understanding (global temperatures have been warmer and CO
2 levels higher) and natural variability; i.e. with atmospheric CO
2 content being too low to have any effect, what caused the early 20th century warming and with it increasing what caused the mid 20th century cooling?
That CO
2 is a greenhouse gas is undeniable, but without it and/or the greenhouse effect, life on Earth would not exist. How one can then claim it is killing people (particularly as it's aiding in planetary re-greening and record crop production) is beyond me. CH
4 is also a greenhouse gas, and one, apparently, more potent than CO
2. However, is one aware that its effect in atmosphere is all but negated because the IR wavelengths at which it's active is already swamped by water vapour? Indeed, its effect is so minuscule it's rarely considered in calculations. And CO
2 has a similar problem insofar as its 'effectiveness' when exposed to planetary weather system dynamics is unknown, hence the variety of calculations for climate sensitivity.
The IPCC, of course, would like us to believe the future to be gloomy, but their imperative is one of political change and as we've seen, they are willing to use any evidence, however sketchy, to support this aim. (CO
2 takes centre stage, not because it's the easiest component of the climate system to work with, but the only one to work with.) The more pragmatic of us take the view that what warming there has been is predominately natural and beneficial and now supported by an increasing accumulation of knowledge. Thus, one has to ask oneself, in the vast, chaotic complexity of the Earth's climate system, can a minor atmospheric trace gas really be a control knob? Try as I may, I just cannot see it.