If by that you mean that the outbound radiation of Earth will increase to provide negative feedback due to black-body radiation, then that's absolutely right. T

If by that you mean that the outbound radiation of Earth will increase to provide negative feedback due to black-body radiation, then that's absolutely right. T^4 in fact, like you said. But if the greenhouse gas levels are coming up 50% higher than they ever were just a few hundred years ago... anyway, I shan't talk about it any more. It is too complex to do justice here.