@jopo, I've seen enough of these discussions to know that you...

@jopo,

I've seen enough of these discussions to know that you are casting pearls before swine when it comes to the immutable laws of Physics and Chemistry. Because the shillery reckons The Science is Settled.

Planetary climate is an outworking of the multiplex interactions between indeterminate numbers of complex, chaotic, open, non-linear and multi-variate chemical and physical systems.

Suffice to say that there are obviously umpteen layers upon layers of variables that are at play which result in inordinate statistical and scientific uncertainty to make "The Science is Settled" be a total contradiction to the field of Science itself.

Earth is a really, tiny cosmic body, with dynamic internal structures and surfaces, covered in part by large bodies of water possessing their own dynamic cycles, and enveloped in a wafer thin blanket of gases, and this vibrant collection of matter is orbiting around a Sun at a speed of 107,000km/hr while the Sun itself is orbiting around the black hole at the centre of our galaxy at a speed of 800,000 km/hr. And all of this is being bombarded with high-energy cosmic gamma rays. And the entire shooting box is subject to all kinds of other factors that are sure to exist and about which we know sweet nothing.

So, in the wake of that diatribe, for anyone to say,

"There is a definite causal relationship between a certain variable and Earth's changing climate and that variable is human activity, to the exclusion of all the other vast matrix of factors." is, by definition, lacking in scientific rigour.

Hence, distilling the influence on a planet's climate down to just one single factor - viz., human activity - to the exclusion of all the other many variables (some which are certainly still unknown) - and then concluding definitive causality, is unscientific on any objective measure.