Your source also says 'The richest 10 percent accounted for half (50 percent) of emissions.'
It’s plausible that very little should be asked of the bottom half, who contribute under ten per cent of emissions if we follow Oxfam’s methodology.⁰ That would exclude nearly everybody in the West, though. And I take it that people on HN do not mean the global middle class when they say ‘middle class’.
0: https://oxfamilibrary.openrepository.com/bitstream/handle/10...