co2 measurements in our atmosphere topped 400 parts per million (ppm) twice in the past six days based on measurements taken daily atop Mt. Mauna Loa in Hawaii. The level Jan. 15 was 400.20, down slightly from the 400.59 measurement the day before.

The level yesterday, Jan. 18, was 399.48.

January 18 - 399.48

January 17 - Unavailable

January 16 - 399.75

January 15 - 400.20

January 14 - 400.59

Week beginning on January 11, 2015: 400.14 ppm

Weekly value from 1 year ago: 397.47 ppm

Weekly value from 10 years ago: 378.61 ppm

Pre-industrial level determined to be 280 ppm

For more information go to http://www.esrl.noaa.gov/gmd/ccgg/trends/weekly.html, or http://keelingcurve.ucsd.edu/