Not all present were scientists (a great many were politicians). In any case "scientists" who sideline discussions off topic aren't any better. The article you posted wasn't relevant at all to the OP.

It is pertinent to a discussion of US Politics that the US was booed - virtually unanimously. Previously the US had us on their side - but now with a change of government that has ceased to be the case.

The US is becoming increasingly more isolated, and as the US economy weakens, unless it begins to recognize that we are all on this planet together, it is likely to become more so.

Although of course China also needs to clean up its act (and in many ways - by no means only WRT carbon emissions) its hypocritical of the US to say 'you first' when the average Chinese carbon footprint is miniscule compared to the average American.

A dose of reality wouldn't hurt.

And the world booing is perhaps a small dose of that.