Other studies and simulations suggest a more substantial rise in temperature will occur even if we were to stop all emissions today. Already there are reports of local hot spots where the temperature rise is on the order of 5 degrees Celsius.

Expressing temperature rise in terms of a probability or likelihood to an accuracy of 1% seems a little strange.

Finally, the hypothesis is poorly stated. Rather than using "hit" it would be better to say "reached or exceeded".

It's so hard watching the Keeling Curve go up 3ppm a year.

500ppm is really not far off. Crossing 400 was so scary. Seeing it march relentlessly up is wild. How can the CO2 more than double in my lifetime? Egads.

We talk about a 1.5C critical rise- but what about after? Does the CO2 go up forever? Does it go to 800 in 2122, where people are just fatigued and fuzzy all the time?