“The CO2 measured at the Mauna Loa Baseline Atmospheric Observatory in Hawaii hit 405.1 parts per million last year, the National Oceanic and Atmospheric Administration announced. ” – Scientific American
We’ve done it again, but really, the record level simply means we haven’t succeeded in reversing the trend. The previous 10,000 years had levels closer to 280 parts per million. Increases have happened, but the recent increases are 100 to 200 times faster than natural. At this rate, we should hit 410 ppm within two years. Carbon Dioxide is a greenhouse gas and persists long enough to increase global temperatures. Even with a reversal in the trend, existing CO2 could continue to increase temperatures. Without a reversal in the trend, effects like rising sea levels, shifting growing seasons, and disruptive weather patterns should continue and increase.

“Atmospheric Carbon Dioxide Hits Record Levels” – Scientific American
Pingback: Data That Matters March 2017 | Pretending Not To Panic