I’ll bet it called for massive transfers of money from the USA and other “wealthy” countries to “poor” countries.
Is this covered by papal infallibility?
No, nothing of the sort would even come close to an infallible teaching. The concern is that forays into climate politics would add to the noise in the political realm, not that it will produce a lasting change in the Church.
Not really. Once he strays from stating principles of faith and morals into proposing specific economic policies as solutions, or endorsing specific scientific theories (e.g., "anthropogenic global warming"), the Pope is not infallible at all.
(One should also note that only a definitive teaching can be infallible; a "suggestion" or "proposal" or "discussion" never is.)