No, the US is responsible for 15% of global CO2 emissions. China emit around twice as much (with around 4x the population), but their emissions aren't growing over the last 10 years. In fact, they have increased their energy consumption by a lot in that decade (commensurate with becoming much richer), partly with renewables and partly by replacing bad uses of fossil fuels with better ones. Neither is their population growing. India and Africa together emit less than the US for around 6x the pop. They have a lot of population growth ahead of them, and a fair amount of getting wealthier, before they start to eat up a 1/4 drop in US emissions.

A bit ridiculous to claim that global warming is caused by the dirt poor and the not yet born 'wanting to consume like Americans' when it's obvious that at least half of Americans are determined to continue consuming like Americans whatever the cost.

Your argument basically seems to boil down to "the most polluting country can't reduce use of its most polluting energy source because other countries exist and emit anything at all".