Thanks for your comment. Continuing to add CO2, as we certainly will do, will continue to warm the earth-atmosphere system - at smaller and smaller rates, approaching infinitesimal. What will be the final warming? the so-called "equilibrium climate sensitivity"(ECS)? Opinions differ (surprise!)
Estimates range from ~0.5 C (Prof Lindzen, MIT) to ~1 C (Judith Curry) to a range between 1 C and 4.5 C (IPCC). I'm quoting from memory; I'm in the ~1 C camp (i.e., "a lukewarmer.") The limit you ask about would be the extreme IPCC value.
I appreciate your concern with "safety" but there is really no choice. Renewables simply can't provide the energy needed to raise 3 billion or so people out of poverty.