What prediction can you make about future levels of carbon dioxide (co2) in the atmosphere?

The CO2 level will rise up to the mark of 508 PPM by 2050.

Explanation:

The CO2 concentration in year 2017 has reached 405 ppm before this period the CO2 concentration has never exceeded 300 ppm.  In the last 800,000 years, CO2 level has reached its maximum in year 2017.  

As per NOAA, the CO2 level has been calculated based on the population estimate of UN and thus there exists three estimates –

a)With low population estimates, the CO2 level will reach 439 PPM by 2050

b)With medium population estimates, the CO2 level will reach 471 PPM by 2050

c)With high population estimates, the CO2 level will reach 508 PPM by 2050

the most speciallized is b. grizzly bear