This trend of increases is evident in the NOAA ESRL global CO2 concentration as measured since January, 1980.
What is more concerning is that the five year rate of increase has moved up to 12.90 ppm compared to February 2013. The return to increasing five year change rates may indicate rising global CO2 emissions as much as the impact of northern hemisphere winter.
Source: NOAA ESRL and Apocalyspe4Real
These global CO2 increases become more stark when placed against earlier base concentration averages.
Since 1980, with a base of 338.45 ppm, a 20.42 percent increase.
Since 1958, with a base of 315.97 ppm a 29.25 percent increase.
Since 1880, with a base of 290.8 ppm, a 40.44 percent increase.
Since 1750, with a base of 278 ppm, a 46.90 percent increase.
It is quite likely the global CO2 monthly average will move above 409 ppm, but less likely to reach a 410 ppm monthly average in May or June of 2018. But a global monthly average above 410 ppm has high probability of occurring in 2019.