I remember the Heartland Institutes mindless hatchet man Russell Cook commenting on the atmospheric CO2 levels when it first went over 400 ppm. He commented how it was just barely over 400 ppm and was only for a few days. This, he claimed, was no need to be concerned.
As in everything else Russell Cook says, it was all a bunch of crap.
On March 8 and 9, there was a dubious event - the hourly measurements exceeded 410 ppm on the Keeling Curve. This, as far as my research has shown, is the highest daily levels ever recorded. But, it doesn't stop there. The daily, weekly and monthly averages are consistently setting new records. I postulated that the last year we would ever see a CO2 level below 400 ppm would be in 2016. The Scripps Institute, which conducts the measurements made on Mauna Loa, stated they believed 2015 was the last year. It now looks as though they were correct.
The monthly average is currently about 407 ppm, with the yearly peak still to come in May. The fall drop is in the range of of 6 or 7 ppm, which means we will not drop below 400 ppm ever again in our lifetimes. The real goal should be, at this time, of stopping us from exceeding 450 ppm. 400 ppm is long gone and we need to stop focusing on it.
You can read the comments from the Scripp's Institute here. They are pretty bleak.
Where's Russell Cook now? Like I said, everything he says, and by extension, the Heartland Institute, is crap. Unfortunately, that is poor solace for a world destined to live with the damage done.