State of Our Climate Atmospheric CO2 Concentration
20 April 2016 Scripps ' Levels exceeded 409 parts per million for the first time in recorded history this month. NOAA 10 Mar 2016 'Carbon dioxide levels are increasing faster than they have in hundreds of thousands of years. It’s explosive compared to natural processes'. Today’s human-made CO2 increase is 200 times faster, a dramatic rate compared to natural processes, Pieter Tans, leader of NOAA’s Global Greenhouse Gas Reference Network
Preindustrial concentration (WMO) CO2 278 ppm
Dec 2016. Press release and links CO2 rate of atmospheric CO2 increase is unprecedented in Earth history at 3 ppm/year 2015 and 2016. Atmospheric CO2 concentration history: it is also the highest in 15-20 million years.
At over 400 ppm atmospheric CO2 is the highest in 15-20 million years 2009 A. Tripati Coupling of CO2 ... of the Last 20 Million Years 2013 Yi Ge Zhang A 40-million-year history of atmospheric CO2