Overall profits would naturally drop if consumers consumed less. Not profit margins. Margins would settle at some arbitrary amount not really tied to our consumption.

In other words prices would not natural decrease. They might even increase. Your personal wealth should increase more though as you overall decide to buy less. Ie. Smaller cars, fewer ATVs, don't upgrade your Xbox as soon.

But with all this additional spare money individuals have because they are consuming less, it is only human nature to eventually spend it and ultimately end up right back with the same personal carbon footprint. The only way I could see a sustained reduction is if governments added significant taxes to nearly every product that was energy intensive in its construction.

In other words food and housing and that car and ATV would need to increase significantly to encourage smaller houses, small cars, purchases of more efficient food stock etc. Things like digital entrainment that have a fixed cost should ultimately have a low carbon footprint as the reproduction of it per person is minimal. The cost would be low.

The ideal ecological system is where people sit at home and watch TV all day expending the least amount of calories so we eat less. People only work the minimal hours to build a ten foot by twenty foot house and ensure they have food and water. Outside of that, have few pleasures. The reality is that people will consume to near the maximum they can afford. And even if you do not consume much and leave your children large inheritances, they will simply do the consumption for you. Just delayed a bit.