Theoretically and what many scientists have said is, no, we still haven't crossed that threshold yet, but are dangerously close.
The problem is that we as a society are not willing to do what is necessary to avoid it. For instance, in electrical generation you have more coal, gas and oil plants than we should have. Yet no one is actually doing something to rapidly get rid of them. Albeit an alternative would be to reduce electrical energy consumption, but I doubt our consumer society will be for that. Another thing is simply allowing certain techs back into the mix like nuclear. We can't just toss it out, we need it as a stop gap measure to maintain a healthy grid if we intend to reduce reliance on fossil fuels.
Cars? People loathe car pooling to reduce cars on the road and public mass transportation is a joke in several developed or developing countries. No real push to get people off the road on single ride car rides. In fact, it seems people are further incentivized to drive more.
Now, doing all that is well and swell, but that still leaves the problem of CO2 still in the air. It won't come out of the atmosphere that easily and it'll take nature a good amount of time to get rid of it. This time will become extended as we refuse to stop deforestation and invest in reforestation projects. Look at the Amazon basin, I believe earlier this year a report came out that it is not a net neutral carbon emitter instead of a net negative. That means loggers down there have cut down enough trees that the Amazon is no longer able to sequester CO2 quickly.
I could go on and on, but you get the gist. We as a collective species simply don't give a flying crap and are content with tossing the can down the road and hitting that snooze button when in reality we are almost at time.
