Trouble is, especiallly when you're talking about 500M people, that term "poverty" is a very slippery and unless defined, pretty meaningless term.
Poverty to someone on benefits in UK city has a different meaning than it does to a war-torn city in Yemen.
Also, even in the UK, thousands of people can enter "poverty" without their living standards changing at all, simply if others living standards went up and theirs didn't.
Poverty nearly always is used as "relative" poerty, which is often polititically loaded but does little to reflect actual hardship in the real world.