Humans have caused 1.5 °C of long-term global warming according to new estimates

Don't take me wrong, I'm not in the denial camp, quite the opposite in fact. But I cringe when I read a non sequitur like this:

> “If you plot global temperatures against the concentration of CO2 in the atmosphere, they both fall on a remarkably straight line, much straighter than current theory would predict,” said Dr Jarvis. “That line tells you not only how much the Earth has warmed since pre-industrial times, but also how much of that warming can be blamed on human activity.”

How can a straight line tell us anything more than a mere correlation between the two measures, without any hint about which is the cause and which is the effect?

Thankfully we have isotopes to demonstrate the cause and effect relation. Why the article doesn't use that instead of this correlation logic, I don't know, so you're not wrong, but it doesn't seem very relevant to argue here about whether it's caused by us when that's well-established in other ways

Isotopes and atmosphere libraries can confirm the sources along with recent satellites that can map CO2 emmissions in real time .. all this goes to confirm the theory of scratched on an envelope a hundred years+ past and laid out in a paper with physics and equations and all that jazz back in '67

“Thermal Equilibrium of the Atmosphere with a Given Distribution of Relative Humidity” - Manabe & Wetherald

Not hard to find and not a bad read for those that passed high school physics and had exposure to first year university STEM coursework.

The basic notion is, well, basic - the more blankets you throw on the bed, the more heat stays trapped.

The blanket in this case is CO2 which is "transparent" to incoming light from the sun but not so transparent to heat energy radiating outwards from the land and sea surface.

The properties here are easy to demonstrate, the increase are documented, the effects followed.