Mate, it's not, it's based on extraordinarily well understood theories around the how chemical bonds and the electromagnetic spectrum work. That is the theory behind the mechanism for anthropogenic climate change is based on exactly the same science that allows big chunks of the infrastructure of civilisation to work - that is, chemistry, quantum physics and arithmetic/accountancy.
You. Literally YOU. Can trivially measure the impact of different gases on temperature.
Telling the difference between natural and human produced is probably not doable by you personally, however, human burned pollution tends to have different atomic markers from naturally occurring. We have mandatory pollution reporting. We can do basic maths to find reasonably close numbers to how much of the pollution is natural and how much is from us.
With regard to “the prediction models are always wrong” fake news propaganda bullshit:
They are always wrong in a way that’s worse for us by underestimating the bad impacts. Every time we improve the models, the outcomes are worse even faster than the models predict, and we have to find why.
Yet you don't know nothing, you believe in catastrophic scenarios.
We can measure anecdotaly that temperature is slightly rising. The reason why is it happening and happend in history multiple times is topic for debate that we can explore.
However your tone is not open for debate and use exactly same words as those you fight against.
It is not “up for debate” that various gasses cause a rise in temperature.
You are pretending that our scientific knowledge is at 1600 levels to come to your insane conclusions.
You claim that I’m not open for debate, but it’s actually just that there is no debate here. You’re a just printing demonstrable lies on to the internet, for what?
posed in ignorance (perhaps genuine ignorance, perhaps feigned) above, we (humans) have been measuring gas properties in isolation for 200 years (and more) and have been specifically measuring (and storing as bottled samples) atmospheric gas composition since the start of the Cold War.. seventy odd years or so now.
Much of our high quality environmental data comes from cold war research - ocean tempretures were first mapped at large scale by Scripps in order to use thermoclines to pinpoint submarines and other sounds in water.
This and other global references informs us about the changing atmospheric makeup and other experiments inform us about the increase in trapped heat from incoming solar radiation.