Well, when the global food chain collapses with the environment, I think 'working people' will be overshadowed by 'starving' people.
Global warming isn't likely to cut total arable land or food production (if anything, it'll likely increase it), but it definitely changes the distribution of arable land. Current breadbaskets like Southern Europe, South Asia, and Brazil might see frequent droughts; currently desolate areas like the Sahara or Canadian Shield may become fertile again. If countries can work out trade deals so that food gets to where it needs to, things can work out. If they start closing borders and saying "fuck you I got mine", there will be widespread starvation and war in many regions.
Canada and Russia becoming new bread baskets is a possible near-term future, but you'll have a lower total amount of incident input energy at those latitudes, meaning that even greater arable land areas will produce significantly less food.
Those are “positive checks” on population.